MI FB API

REVISION HISTORY¶

Revision No.	Description	Date
3.0	Initial release	07/27/2021
	Modify Figure 1-1, the graphics layer supports overlaying to the SCL PATH, and added related instructions In section 1.5, the chip difference part added the graphics layer overlay to the SCL PATH support in different chips In Section 1.7, added INI parameters configuration	08/08/2021
	Added procfs introduction	08/25/2021
	Refine HW_LAYER_ID and Refine chip difference table	12/17/2021
	Added the difference table of Mochi	02/16/2022
	Added the difference table of Maruko	03/21/2022
	Added support for API “FBIO_WAITFORVSYNC”	04/11/2022
	Added a detailed introduction of FB_BUFFER_LEN	07/07/2022
	Modified "Configure MI_FB startup parameters"	07/08/2022
	Refined procfs & Added error code	11/10/2023
	Added the difference table of Iford	11/13/2023
	Added the difference table of Pcupid	04/16/2024
	Added the description of overlay layer blending position	08/26/2024
	Added the description of Alpha Blending mode	08/26/2024
	Added the description of Modparam	10/30/2024

1. OVERVIEW¶

1.1. Module Description¶

MI_FB is a graphics layer device driver based on Linux Framebuff. It abstracts the display buffer, shields the bottom-level difference of the image hardware, and allows the upper-level APP to directly read and write the display buffer in the graphics mode. The specific location and storage method of the physical display buffer is completed by MI_FB driver. In addition to providing basic functions of Linux Framebuff, MI_FB also provides extended functions such as Alpha between layers, ColorKey, and display area setting.

1.2. Basic Structure¶

MI_FB manages multiple graphics layers. With chip support, each graphics layer can be overlaid on different video processing/output paths.

The video preview overlay path means that the graphics layer can be overlaid on the video display unit which is managed by MI_DISP submodule. If the graphics layer is overlaid on the video display unit, you need to configure MI_DISP submodule first, and then operate MI_FB submodule to draw the graphics layer, finally, the video display unit outputs the overlaid video data to the display device, and the video display unit determines the final display resolution.
Video processing overlay path means that the graphics layer can be overlaid on the video processing unit which is managed by MI_SCL submodule. If the graphics layer is overlaid on the video processing unit, you need to configure MI_SCL submodule, and then operate MI_FB submodule to draw the graphics layer, finally, the video processing unit outputs the overlaid video data to the video encoding unit or to the video display unit for preview playback.

Figure 1‑1: Graphics layer overlay path

From the perspective of application development, there are two ways to draw the graphics layer based on MI_FB.

Method 1: APP uses MI_FB based on Linux file system.

Method 2: Develop APP based on the API provided by MI_FB.

Figure 1‑2: MI_FB usage

Note: The two methods are mutually exclusive, only one of them can be selected for development.

1.3. Module Function¶

Linux Framebuff standard functions supported by MI_FB:

Get fixed info of display device (such as video memory size)
Map (or unmap) physical video memory to virtual memory space
Operate physical video memory like ordinary files
Set hardware display resolution and pixel format
Read, write, display and other operations from any location in the physical video memory
Support setting and obtaining 256-color palette

Extended functions added by MI_FB:

Set and get the Alpha value of the overlay graphics layer
Set and get the ColorKey value of the overlay graphics layer
Set the display position of the current overlay graphics layer (the offset relative to the origin of the screen)
Set the display area of the current overlay graphics layer (supports canvas enlargement display)
Set and get the display status of the current overlay (show/hide)
Manage the size of physical video memory and the number of overlay graphics layers through INI config file
Dynamically synchronized display device output resolution
Support the operation of the CURSOR graphics layer

Linux Framebuff standard functions not supported by MI_FB:

Set and get the Linux Framebuff corresponding to the console
Get real-time info of hardware scanning
Get hardware related info
Set hardware sync timing
Set hardware sync signal mechanism

1.4. Application Scenario¶

Pure Linux

Framebuff-based applications in Linux (such as MiniGUI) can also be developed based on the API interface provided by MI_FB.
Pure rtos

The standard Linux Framebuff framework is not supported under RTOS. Applications can develop UI based on the API interface provided by MI_FB (such as using lightweight lvgl to develop UI).
Dualos

In Dualos, applications running on Linux can be developed based on the standard Framebuff framework or MI_FB API; applications running on RTOS can only be developed based on MI_FB API.

1.5. Chip Difference¶

MI_FB has two forms of user interface. MI_FB adds the concept of FB ID to keep user behavior consistent. The following figure shows the relationship between FB ID and Framebuff device node.

Figure 1‑3: FB ID and device node relationship

MI_FB defines the ID growth sequence to be consistent with the device node of Framebuff, that is, /dev/fbxxx corresponds to FB IDxxx.

Each FB ID of MI_FB controls at most one GUI and one CURSOR layer, which means that the application can use the same FB ID to operate the GUI and CURSOR layer bound to the ID at the same time, GUI can be superimposed on video display unit or video processing unit, the CURSOR layer can only be superimposed on video display unit, and the superimposed output path of GUI and the CURSOR layer is configured in config.ini. Section 1.7.2 describes in detail how to configure the INI.

MI_FB can manage 16 FB IDs. The specific supported IDs are related to the chip capabilities. The differences between different chips are shown in the following table:

The Layer ID corresponds to FB_HWLAYER_ID items in the MI_FB startup parameters, please refer to the Layer ID when configuring the startup parameters.
The hierarchical relationship between different graphics layers in the same video display unit with the same PATH is GUI -> OSD -> CURSOR from bottom up.
Alpha0/1 indicates the actual Alpha value when the color format is ARGB1555 and the Alpha bit is 0/1. On some graphics layers, alpha1 is only supported and Alpha 0 is not supported, which is marked N.

Please refer to the detailed information Section 1.5.11 about the current chip (Pcupid).

1.5.1. Taiyaki¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

CURSOR

0

N

Y

N

Y

N

Y

1.5.2. Takoyaki¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

CURSOR

0

N

Y

N

Y

N

Y

1.5.3. Ispahan¶

Graphics layer		Layer ID	Color Format							Scale Up	Alpha0/1
Graphics layer		Layer ID	ARGB8888	ARGB1555	ARGB4444	RGB565	I2	I4	I8	Scale Up	Alpha0/1
Video processing unit	GUI	NA	N	Y	Y	N	N	N	Y	N	Y

1.5.4. Pudding¶

Graphics layer		Layer ID	Color Format							Scale Up	Alpha0/1
Graphics layer		Layer ID	ARGB8888	ARGB1555	ARGB4444	RGB565	I2	I4	I8	Scale Up	Alpha0/1
Video processing unit	GUI	NA	N	Y	Y	N	N	N	Y	N	Y

1.5.5. Ikayaki¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

1.5.6. Tiramisu¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

CURSOR

0

N

Y

N

Y

N

Y

DISP PATH1

GUI

3

Y

N

Y

N

CURSOR

2

N

Y

N

Y

N

Y

Video processing unit

GUI

NA

N

Y

N

Y

N

Y

1.5.7. Muffin¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

CURSOR

0

N

Y

N

Y

N

Y

OSD

2

N

Y

N

Y

N

Y

DISP PATH1

GUI

9

Y

N

Y

N

CURSOR

8

N

Y

N

Y

N

Y

OSD

10

N

Y

N

Y

N

Y

DISP PATH2

GUI

17

Y

N

Y

N

CURSOR

16

N

Y

N

Y

N

Y

OSD

18

N

Y

N

Y

N

Y

Video processing unit

GUI

NA

N

Y

N

Y

N

Y

The video display unit of the Muffin series of chips has added an OSD graphics layer, typically as the default graphics layer that MI_RGN overlaid to DISP, and if MI_FB wants to use the OSD graphics layer, MI_RGN cannot overlay the OSD to DISP.

1.5.8. Mochi¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

N

CURSOR

0

N

Y

N

Y

N

Y

OSD

2

N

Y

N

Y

N

Y

DISP PATH1

GUI

9

Y

N

Y

N

CURSOR

8

N

Y

N

Y

N

Y

OSD

10

N

Y

N

Y

N

Y

Video processing unit

GUI

NA

N

Y

N

Y

N

Y

The video display unit of the Mochi series of chips has added an OSD graphics layer, typically as the default graphics layer that MI_RGN overlaid to DISP, and if MI_FB wants to use the OSD graphics layer, MI_RGN cannot overlay the OSD to DISP.

1.5.9. Maruko&Souffle¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

2

Y

N

Y

N

Y

Video processing unit

GUI

NA

N

Y

N

Y

N

Y

Video display unit GUI layer, video processing unit GUI layer and SCL/DISP OSD in MI_RGN share the same hardware. FB cannot be used when MI_RGN superimposes OSD on SCL/DISP. And vice versa.

1.5.10. Iford¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

2

Y

N

Y

N

Y

Video processing unit

GUI

NA

N

Video display unit GUI layer and DISP OSD in MI_RGN share the same hardware. FB cannot be used when MI_RGN superimposes OSD on DISP. And vice versa.

1.5.11. Pcupid¶

Graphics layer

Layer ID

Color Format

Scale Up

Alpha0/1

ARGB8888

ARGB1555

ARGB4444

RGB565

I2

I4

I8

Video display unit

DISP PATH0

GUI

1

Y

N

Y

1.6. Principle¶

1.6.1 Graphics layer refresh mode¶

Single buff mode

Figure 1‑4: Single buff refresh mode

In this mode, MI_FB provides a display buff, and app draw directly, which can save memory, but user will see the drawing process of the graphics on the display device. You can also apply for another buff for graphics drawing, and then move it to display buff, but this method will produce jagged.
Double buff mode

Figure 1‑5: Double buff refresh mode

In this mode, MI_FB provides two display buffs. When the graphics layer device is using display buff2, you can draw on buff1, and then switch to the starting position of buff1 by setting the virtual screen offset position. It consumes more memory, but the display effect is the best.

1.6.2 Relationship between virtual screen resolution, visible area and display resolution¶

Figure 1‑6: Relationship between resolutions

The virtual screen size can be regarded as the video memory size provided by MI_FB. You can define the resolution of the visible area (xres, yres) in the config file. MI_FB will adjust the virtual screen resolution (xres_virtual, yres_virtual) according to the range of the visible area. The default screen resolution is xres_virtual=xoffset+xres, xoffset is the offset of the visible area in the horizontal direction of the virtual screen, and xres is width.

MI_FB adjusts yres_virtual according to xres_virtual, pixel format and video memory size; you can freely change the visible area (xoffset, yoffset) within the range of (xres_virtual, yres_virtual) to switch the display content, and the double-buff refresh mode is also implemented based on this.

The graphics layer device reads the memory data from the visible area, and then outputs it to the display device according to the display area attributes configured by user. The display area attributes include the display area range and the offset position relative to the origin of the display screen.

The process from the visible area to the display area supports magnification, that is, the visible area (xres, yres) < display area (dst_width, dst_height) ≤ display device resolution (display width, display height), and the display device resolution is decided by output MI_DISP Timing.

1.7. Development Process¶

1.7.1 Compile Config¶

Enter alkaid project root directory, make menuconfig
Press Enter to enter the Sdk Config sub-option
Press Enter to enter the Interface Compile Config sub-option
Press Space bar to select the fb module
Press Enter to enter the fb module, select the sub-option supported by the chip and recompile the project

After compilation, mi_fb.ko will generated in project/release, and release mi_fb.h and mi_fb_datatype.h to this directory at the same time. It will be packaged into images by default in pure Linux. But in dualos, it will not be packaged by default and needs to be manually compiled and installed.

1.7.2 Configure MI_FB startup parameters¶

MI_FB startup parameters are managed in config.json. “fb_device_disp_path” and “fb_device_video_path” defined in the config.json describes the entry of GUI or Cursor layer parameters of the current platform.

“fb_device_disp_path” describes the configuration information superimposed on the GUI and cursor of the video display unit;
“fb_device_video_path” describes the configuration information superimposed on GUI of the video processing unit.

{
    "mi_fb": {
        "fb_device_disp_path": [
            {
                "fb_hwlayer_id": 1,
                "fb_hwwin_id": 0,
                "fb_hwwin_format": 5,
                "fb_hwlayer_dst": 3,
                "fb_hwlayer_outputcolor": 0,
                "fb_width": 1920,
                "fb_height": 1080,
                "fb_timing_width": 1920,
                "fb_timing_height": 1080,
                "fb_mmap_name": "E_MMAP_ID_FB",
                "fb_buffer_len": 16384,
                "cursor": {
                    "fb_hwlayer_id": 0,
                    "fb_hwwin_id": 0,
                    "fb_hwwin_format": 6,
                    "fb_mmap_name": "E_MMAP_ID_HW_CURSOR"
                }
            },
            {
                //Other GUI and cursor attach to disp path. (If the chip supports)
            }
        ],
        "fb_device_video_path": [
            {
                "fb_buf_id_path": {
                    "fb_gwin_id": 7,
                    "fb_mod": 34,
                    "fb_dev": 1,
                    "fb_chn": 0,
                    "fb_port": 0
                },
                "fb_hwwin_format": 6,
                "fb_width": 1920,
                "fb_height": 1080,
                "fb_timing_width": 1920,
                "fb_timing_height": 1080,
                "fb_buf_cnt": 3
            },
            {
                // Other GUI attach to video path. (If the chip supports)
            }
        ]
    }
}

Note:

1. Adding multiple GUI layers (if supported by the chip) needs to add the new node to “fb_device_disp_path” and “fb_device_video_path” for management.

2. The growth order of /dev/fbxxx device nodes is consistent with the order in path, “fb_device_disp_path” comes first.

The description of each configuration parameter in config.json is as follows:

Parameter	Description
fb_hwlayer_id	The current graphics layer ID (determine which output PATH of the video layer device DISP is superimposed on)
fb_hwwin_id	Hardware device ID
fb_hwwin_format	Describe the canvas pixel format
fb_hwlayer_dst	Describe the location of the current overlay layer blending to the video layer device DISP (OSDB1 foreground/OSDB2 background)
fb_hwlayer_outputcolor	Describe the color space (YUV/RGB) output by the current overlay
fb_width	Describe the visible area range (xres)
fb_height	Describe the visible area range (yres)
fb_timing_width	Describe the display device resolution (display width)
fb_timing_height	Describe the display device resolution (display height)
fb_mmap_name	Video memory application related parameters (default is E_MMAP_ID_FB)
fb_buffer_len	Describe the video memory size (unit: Kbyte)
fb_buf_cnt	Calculate the video memory size of the graphics layer superimposed on the video processing unit
fb_gwin_id	Superimpose the graphics layer GWIN ID of video processing unit
fb_mod	Superimpose the graphics layer MODULE ID of video processing unit
fb_dev	Superimpose the graphics layer DEV ID of video processing unit
fb_chn	Superimpose the graphics layer CHN ID of video processing unit
fb_port	Superimpose the graphics layer PORT ID of video processing unit

Note:

There are two positions where the overlay layer can be blended to the video layer, such as OSDB1 and OSDB2 in Figure 1-7 and Figure 1-8. The blending position is determined by using fb_hwlayer_dst and fb_hwlayer_outputcolor together.
There are two color space conversion units (CSC1 and CSC2) in the video layer, and only one of them will be passed through.
As shown in Figure 1-7, the video layer only passes through color space conversion unit 1, and both OSDB1 and OSDB2 are RGB format data (overlay layer blending to OSDB1 and OSDB2 has the same effect)
- fb_hwlayer_dst = 3, overlay layer blending to OSDB1;
  - fb_hwlayer_outputcolor = 0, the overlay outputs RGB format data
- fb_hwlayer_dst = 12, overlay layer blending to OSDB2;
  - fb_hwlayer_outputcolor = 0, the overlay outputs RGB format data
Figure 1-7 Video layer only passes through color space conversion unit 1
As shown in Figure 1-8, the video layer only passes through color space conversion unit 2, OSDB1 is YUV format data, and OSDB2 is RGB format data
- fb_hwlayer_dst = 3, overlay layer blending to OSDB1;
  - fb_hwlayer_outputcolor = 1, the overlay outputs YUV format data
- fb_hwlayer_dst = 12, overlay blending to OSDB2;
  - fb_hwlayer_outputcolor = 0, the overlay outputs RGB format data
Figure 1-8 Video layer only passes through color space conversion unit 2
By default, the Pcupid video layers only pass through color space conversion unit 1. For a detailed introduction to the color space conversion unit, please refer to the MI_DISP_API document.

1.7.3 Alpha Blending Mode Description¶

Alpha blending can blend the pixels of the current overlay layer with the video layer. There are currently four optional alpha blending modes.

Mode	Calculation Formula
Non-premultiplied mode	pix_color = src_color * src_alpha + dst_color * (1 - src_alpha )
Non-premultiplied mode + plane transparency	pix_color = src_color * src_alpha * plane_alpha + dst_color * (1 - src_alpha * plane_alpha )
Premultiplied mode	pix_color = src_color + dst_color * (1 - src_alpha )
Premultiplied mode + plane transparency	pix_color = src_color * plane_alpha + dst_color * (1 - src_alpha * plane_alpha )

Parameter Description:

color: The color value. When the overlay outputs in YUV format, it represents the YUV component; when the overlay outputs in RGB format, it represents the RGB component
pix_color : The color value of the current pixel after blending
src_color : The color value of the current pixel in the overlay layer
dst_color : The color value of the current pixel in the video layer
src_alpha : The alpha value of the current pixel in the overlay layer, ranging from [0, 1]
plane_alpha : The plane transparency value, value range [0, 0xFFFF], normalized in hardware

Related interfaces:

MI_FB_AlphaMode_e
MI_FB_GetGlobalAlpha
MI_FB_SetGlobalAlpha

1.7.4 Calculation of video memory size at different layers¶

For the GUI layer of "fb_device_disp_path", it is necessary to calculate the maximum memory that may be used in the actual application scenario in advance and fill in "fb_buffer_len". This value is usually determined by the following points:

Maximum UI resolution: W * H
The largest BPP(Byte Per Pixel, such as the BPP of ARGB8888 is 4) in color format
Number of buffer: NUM

fb_buffer_len = W * H * BPP * NUM / 1024 (KByte)

If GUI’s setting includes “cursor” field, FB will apply for 0x20000 Bytes memory for the cursor layer when the corresponding FB_DEVICE applies for memory.

For the GUI layer of "fb_device_video_path", the FB will calculate the required memory size according to FB_WIDTH / FB_HEIGHT / FB_HWWIN_FORMAT / FB_BUF_CNT in the configuration file.

1.7.5 Configure display memory pool for MI_FB¶

The default mma_heap uses a 64-bit physical address space. In the standard framebuffer framework, unsigned long is used to define variables that store physical addresses. If 32-bit compiler is used, data will be lost in a 32-bit environment.

In order to avoid the above errors, it is necessary to configure a separate mma_heap for fb in bootargs and ensure that its address space is within a 32-bit representable range in MI_SYS

The bootargs parameters that need to be added are as follows:

mma_heap=mma_heap_fb,miu=0,sz=0x2040000

Parameter meaning:

mma_heap : Define private pool name
miu : Specify miu id
sz : Specify the size of the private pool

This parameter is configured by default, you can adjust sz as needed.

sz is calculated as follows:

For each additional disp path GUI, add the corresponding fb_buffer_len (KByte).
For each additional cursor, add 0x20000 Bytes (128 KBytes).
For each additional video path GUI, add the memory size required for the fb_device_video_path layer.
For the specific calculation method, please refer to: 1.7.4 Calculation of video memory size at different layers

1.7.6 Interface call¶

There are two types of interface calls: File system call based on standard Linux Framebuff; Interface call based on MI_FB API. Both of them are achieving the same function.

Figure 1‑9: MI_FB interface call process

Steps:

Open the specified FB device
Set pixel format, visible area, etc.
Get video memory info allocated to MI_FB
Map physical video memory to virtual memory space
Call ioctl or MI_FB API to set ColorKey, inter-layer Alpha, display position and area, etc
Operate the virtual memory address to complete the specific drawing task
Unmap video memory
Close the FB device
Exit

1.8. Example¶

This example is based on Linux Framebuff and MI_FB API to display three color blocks arranged in steps of red, orange and blue in the middle of the screen, using the ARGB8888 pixel format.

#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/fb.h>
#include "mi_sys.h"
#include "mi_disp.h"
#include "mi_disp_datatype.h"
#include "mi_fb.h"
#include "mi_fb_datatype.h"

#define LINUX_FRAMEBUFF
#define YUYV_BLACK (0x800080)

static void *framebuffer = NULL;

void set_disp_dev(void)
{
    MI_DISP_PubAttr_t stPubAttr;
    memset(&stPubAttr, 0, sizeof(MI_DISP_PubAttr_t));
    stPubAttr.u32BgColor = YUYV_BLACK;
    stPubAttr.eIntfType  = E_MI_DISP_INTF_TTL;
    stPubAttr.eIntfSync  = E_MI_DISP_OUTPUT_USER;
    MI_DISP_SetPubAttr(0, &stPubAttr);
    MI_DISP_Enable(0);

    MI_DISP_VideoLayerAttr_t stVideoLayerAttr;
    stVideoLayerAttr.stVidLayerDispWin.u16X      = 0;
    stVideoLayerAttr.stVidLayerDispWin.u16Y      = 0;
    stVideoLayerAttr.stVidLayerDispWin.u16Width  = 1024;
    stVideoLayerAttr.stVidLayerDispWin.u16Height = 600;
    stVideoLayerAttr.stVidLayerSize.u16Width     = 1024;
    stVideoLayerAttr.stVidLayerSize.u16Height    = 600;
    MI_DISP_BindVideoLayer(0, 0);
    MI_DISP_SetVideoLayerAttr(0, &stVideoLayerAttr);
    MI_DISP_EnableVideoLayer(0);
}

#ifdef LINUX_FRAMEBUFF
static struct fb_var_screeninfo vinfo = {0};
static struct fb_fix_screeninfo finfo = {0};
// Based on Linux Framebuff
void drawRect_rgb32 (int x0, int y0, int width, int height, int color, struct fb_var_screeninfo *vinfo, struct fb_fix_screeninfo *finfo, char *fb)
{
    const int bytesPerPixel = 4;
    const int stride = finfo->line_length / bytesPerPixel;

    int *dest = (int *) (fb)
        + (y0 + vinfo->yoffset) * stride + (x0 + vinfo->xoffset);

    int x, y;
    for (y = 0; y < height; ++y)
    {
        for (x = 0; x < width; ++x)
        {
            dest[x] = color;
        }
        dest += stride;
    }
}

int main(int argc, char **argv)
{
    const char *devfile = "/dev/fb0";
    int fbFd = 0;
    long int screensize = 0;

    MI_SYS_Init(0);

    //set disp pub
    set_disp_dev();
    fbFd = open(devfile, O_RDWR);
    if(fbFd == -1)
    {
        perror ("Error: cannot open framebuffer device");
        exit(1);
    }
    //get fb_fix_screeninfo
    if(ioctl(fbFd, FBIOGET_FSCREENINFO, &finfo) == -1)
    {
        perror("Error reading fixed information");
        exit(2);
    }
    //get fb_var_screeninfo
    if(ioctl(fbFd, FBIOGET_VSCREENINFO, &vinfo) == -1)
    {
        perror("Error reading variable information");
        exit(3);
    }
    screensize = finfo.smem_len;

    /* Map the device to memory */
    framebuffer = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED,
            fbFd, 0);
    if(framebuffer == MAP_FAILED)
    {
        perror ("Error: Failed to map framebuffer device to memory");
        exit (4);
    }
    //draw red rectangle
    drawRect_rgb32 (vinfo.xres / 8, vinfo.yres / 16,
            vinfo.xres / 4, vinfo.yres / 4, 0xffff0000, &vinfo, &finfo, framebuffer);

    //draw DarkGoldenrod rectangle
    drawRect_rgb32 (vinfo.xres * 3 / 8, vinfo.yres * 5 / 16,
            vinfo.xres / 4, vinfo.yres / 4, 0xffb8860b, &vinfo, &finfo, framebuffer);

    //draw blue rectanble
    drawRect_rgb32 (vinfo.xres * 5 / 8, vinfo.yres * 9 / 16,
            vinfo.xres / 4, vinfo.yres / 4, 0xff0000ff, &vinfo, &finfo, framebuffer);

    munmap(framebuffer, screensize);
    framebuffer = NULL;

    close(fbFd);

    return 0;
}
#else
static MI_FB_VarScreenInfo_t stVarScreenInfo = {0};
static MI_FB_FixScreenInfo_t stFixScreenInfo = {0};
// Based on MI_FB API
void drawRect_rgb32(int x0, int y0, int width, int height, int color, MI_FB_VarScreenInfo_t *vinfo, MI_FB_FixScreenInfo_t *finfo, char *fb)
{
    const int bytesPerPixel = 4;
    const int stride = finfo->u32LineLength/ bytesPerPixel;

    int *dest = (int *) (fb)
        + (y0 + vinfo->u32Yoffset) * stride + (x0 + vinfo->u32Xoffset);

    int x, y;
    for (y = 0; y < height; ++y)
    {
        for (x = 0; x < width; ++x)
        {
            dest[x] = color;
        }
        dest += stride;
    }
}

int main(int argc, char **argv)
{
    MI_S32 s32Ret = 0;
    MI_U8 u8FbId = 0;
    MI_U32 screensize = 0;

    MI_SYS_Init(0);

    //set disp pub
    set_disp_dev();

    s32Ret = MI_FB_Open(u8FbId);
    if(s32Ret != MI_SUCCESS)
    {
        printf("open fb id:%d failed\n", u8FbId);
        exit(1);
    }
    s32Ret = MI_FB_GetFixScreenInfo(u8FbId, &stFixScreenInfo);
    if(s32Ret != MI_SUCCESS)
    {
        printf("get fix screen info failed\n");
        exit(2);
    }

    s32Ret = MI_FB_GetVarScreenInfo(u8FbId, &stVarScreenInfo);
    if(s32Ret != MI_SUCCESS)
    {
        printf("get var screen info failed\n");
        exit(3);
    }
    screensize = stFixScreenInfo.u32SmemLen;
    MI_FB_Mmap(u8FbId, screensize, &framebuffer);
    if(!framebuffer)
    {
        printf("mmap framebuffer failed\n");
        exit(4);
    }
    //draw red rectangle
    drawRect_rgb32 (stVarScreenInfo.u32Xres / 8, stVarScreenInfo.u32Yres/ 8,
         stVarScreenInfo.u32Xres / 4, stVarScreenInfo.u32Yres / 4, 0xffff0000, &stVarScreenInfo, &stFixScreenInfo, framebuffer);

    //draw DarkGoldenrod rectangle
    drawRect_rgb32 (stVarScreenInfo.u32Xres * 3 / 8, stVarScreenInfo.u32Yres * 3 / 8,
         stVarScreenInfo.u32Xres / 4, stVarScreenInfo.u32Yres / 4, 0xffb8860b, &stVarScreenInfo, &stFixScreenInfo, framebuffer);

    //draw blue rectanble
    drawRect_rgb32 (stVarScreenInfo.u32Xres * 5 / 8, stVarScreenInfo.u32Yres * 5 / 8,
            stVarScreenInfo.u32Xres / 4, stVarScreenInfo.u32Yres / 4, 0xff0000ff, &stVarScreenInfo, &stFixScreenInfo, framebuffer);

    MI_FB_Munmap(u8FbId, framebuffer, screensize);
    framebuffer = NULL;

    MI_FB_Close(u8FbId);
    return 0;
}
#endif

2. API REFERENCE¶

Two forms of MI_FB user mode interface:

File operations based on Linux Framebuff, embodied in the form of ioctl. int ioctl(int fd, unsigned long cmd, CMD_DATA_TYPE *cmddata); CMD_DATA_TYPE changes with the parameter cmd, the cmd supported by MI_FB is as follows.

Parameter	Description	Input/Output
fd	The descriptor of Framebuffer device file, which is the return value of calling the open function.	Input
cmd	The main cmds are as follows: FBIOGET_VSCREENINFO: Get screen variable info FBIOPUT_VSCREENINFO: Set screen variable info FBIOGET_FSCREENINFO: Get screen fixed info FBIOPAN_DISPLAY: Set PAN display FBIOGETCMAP: Get color table info FBIOPUTCMAP: Set color table info FBIOGET_SCREEN_LOCATION: Get the overlay display area FBIOSET_SCREEN_LOCATION: Set the overlay display area FBIOGET_SHOW: Get the overlay display status FBIOSET_SHOW: Set the overlay display status FBIOGET_GLOBAL_ALPHA: Get the overlay Alpha attribute FBIOSET_GLOBAL_ALPHA: Set the overlay Alpha attribute FBIOGET_COLORKEY: Get the overlay Colorkey attribute FBIOSET_COLORKEY: Set the overlay Colorkey attribute FBIOGET_DISPLAYLAYER_ATTRIBUTES: Get overlay attribute FBIOSET_DISPLAYLAYER_ATTRIBUTES: Set overlay attribute FBIOGET_CURSOR_ATTRIBUTE: Get Cursor layer attribute FBIOSET_CURSOR_ATTRIBUTE: Set Cursor layer attribute FBIOGET_COMPRESSIONINFO: Get compressed information FBIOSET_COMPRESSIONINFO: Set compressed information	Input
cmddata	Data type corresponding to cmd: Get or set screen variable info: struct fb_var_screeninfo type Get screen fixed info: struct fb_fix_screeninfo type Set PAN display: struct fb_var_screeninfo type Get or set the origin of the screen overlay coordinate: MI_FB_Rectangle_t type Get or set the overlay display status: MI_BOOL type Get or set the overlay Alpha: MI_FB_GlobalAlpha_t type Get or set the overlay Colorkey: MI_FB_ColorKey_t type Get or set the overlay attribute: MI_FB_DisplayLayerAttr_t type Get or set Cursor layer attribute: MI_FB_CursorAttr_t type Get or set compressed information: MI_FB_Compression_t type	Input/Output

Based on MI_FB API in the form of dynamic library or static library, the following APIs are currently supported.

API name	Function
MI_FB_Open	Open FB device
MI_FB_Close	Close FB device
MI_FB_Mmap	Map physical video memory to virtual memory space
MI_FB_Munmap	Unmap physical video memory to virtual memory space
MI_FB_GetVarScreenInfo	Get screen variable info
MI_FB_SetVarScreenInfo	Set screen variable info
MI_FB_GetFixScreenInfo	Get FB fixed info
MI_FB_PanDisplay	Set the display to start at a different offset in the virtual resolution
MI_FB_WaitForVsync	Wait for a signal that screen vertical refresh is complete(Vsync)
MI_FB_GetScreenLocation	Get the display area of the overlay on screen
MI_FB_SetScreenLocation	Set the display area of the overlay on screen
MI_FB_GetDisplayLayerAttr	Get layer info
MI_FB_SetDisplayLayerAttr	Set layer info
MI_FB_GetCursorAttr	Get Cursor layer info
MI_FB_SetCursorAttr	Set Cursor layer info
MI_FB_GetGlobalAlpha	Get overlay Alpha
MI_FB_SetGlobalAlpha	Set overlay Alpha
MI_FB_GetColorKey	Get overlay colorkey
MI_FB_SetColorKey	Set overlay colorkey
MI_FB_SetCmap	Set the color table
MI_FB_GetCmap	Get color table
MI_FB_GetShow	Get the overlay display status
MI_FB_SetShow	Show or hide the overlay
MI_FB_GetCompressionInfo	Get compressed information
MI_FB_SetCompressionInfo	Set compressed information

Section 1.4 introduces the use of two forms of API in different scenarios, you can choose to use one of them according to the actual situation.

Note: Only one of the two calling methods can be selected.

2.1. Standard Function¶

2.1.1 FBIOGET_VSCREENINFO¶

Function

Get screen variable information

Syntax

int ioctl (int fd, FBIOGET_VSCREENINFO, struct fb_var_screeninfo *var);

Description

Use this interface to get screen variable information, including primarily resolution and pixel format.
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_VSCREENINFO ioctl cmd Input

var Variable information structure pointer Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h
Related Interface

FBIOPUT_VSCREENINFO

2.1.2 FBIOPUT_VSCREENINFO¶

Function

Set Framebuffer screen resolution and pixel format, etc.

Syntax

int ioctl (int fd, FBIOPUT_VSCREENINFO, struct fb_var_screeninfo *var);

Description

Use this interface to set screen resolution and pixel format
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOPUT_VSCREENINFO ioctl cmd Input

var Variable information structure pointer Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h
Note

The actual resolution and offset must be guaranteed to be within the virtual resolution range. Otherwise, system will automatically adjust the actual resolution to keep it within the coverage of the virtual resolution range.
Related Interface

FBIOGET_VSCREENINFO

2.1.3 FBIOGET_FSCREENINFO¶

Function

Get Framebuffer fixed information

Syntax

int ioctl (int fd, FBIOGET_FSCREENINFO, struct fb_fix_screeninfo *fix);

Description

Use this interface to get Framebuffer fixed information, including memory start physical address, memory size and line spacing, etc.
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_FSCREENINFO ioctl cmd Input

fix Fixed information structure pointer Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h

2.1.4 FBIOPAN_DISPLAY¶

Function

Set to display from different offsets in the virtual resolution

Syntax

int ioctl (int fd, FBIOPAN_DISPLAY, struct fb_var_screeninfo *var);

Description

Use this interface to set the display position from different offsets in the virtual resolution; the actual resolution remains unchanged. As shown in the Figure 2-1 below, (xres_virtual, yres_virtual) means the virtual resolution, (xres, yres) the resolution actually shown, and (xoffset, yoffset) the offset used.
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOPAN_DISPLAY ioctl cmd Input

var Variable information structure pointer Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h
Note

The actual resolution and offset must be guaranteed to be within the virtual resolution range. Otherwise, the setting will fail.

Figure 2‑1 Setting the Display Position from Different Offsets in the Virtual Resolution

2.1.5 FBIO_WAITFORVSYNC¶

Function

Wait for a signal that screen vertical refresh is complete(Vsync).

Syntax

int ioctl (int fd, FBIO_WAITFORVSYNC, u32 *zero);

Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGETCMAP ioctl cmd Input

zero be sure to pass argument value 0 or it will not work. Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h

2.1.6 FBIOGETCMAP¶

Function

Get color table info.

Syntax

int ioctl (int fd, FBIOGETCMAP, struct fb_cmap_user *cmap);

Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGETCMAP ioctl cmd Input

cmap Describe the color table info Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h
Related Interface

FBIOPUTCMAP

MI_FB_SetCmap

2.1.7 FBIOPUTCMAP¶

Function

Set color table info.

Syntax

int ioctl (int fd, FBIOPUTCMAP, struct fb_cmap_user *cmap);

Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOPUTCMAP ioctl cmd Input

cmap Describe the color table info Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: fb.h
Related Interface

FBIOGETCMAP

MI_FB_GetCmap

2.2. Extended Function¶

2.2.1 FBIOGET_SCREEN_LOCATION¶

Function

Get overlay screen display region

Syntax

int ioctl (int fd, FBIOGET_SCREEN_LOCATION, MI_FB_Rectangle_t* pstRectangle);

Description

Use this interface to get overlay screen display region

Parameter

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_SCREEN_LOCATION	ioctl cmd	Input
pstRectangle	Pointer to MI_FB_Rectangle_t structure, including (x,y) coordinates, width, and height. It refers to the overlay screen display region.	Output

Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_SCREEN_LOCATION

2.2.2 FBIOSET_SCREEN_LOCATION¶

Function

Set overlay screen display region

Syntax

int ioctl (int fd, FBIOSET_SCREEN_LOCATION, MI_FB_Rectangle_t* pstRectangle);

Description

Use this interface to set overlay screen display region

Parameter

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_SCREEN_LOCATION	ioctl cmd	Input
pstRectangle	Pointer to MI_FB_Rectangle_t structure, including (x, y) coordinates, width, and height. It refers to the overlay screen display region.	Input

Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_SCREEN_LOCATION

2.2.3 FBIOGET_SHOW¶

Function

Get current overlay display status

Syntax

int ioctl (int fd, FBIOGET_SHOW, MI_BOOL *bShow);

Description

Use this interface to get current overlay display status

Parameter

Parameter Name	Description	Input/Output
Fd	Framebuffer device file descriptor	Input
FBIOGET_SHOW	ioctl cmd	Input
bShow	Indicate the current overlay status: bShow = MS_TRUE: Current overlay is in Show status bShow = MS_FALSE: Current overlay is in Hidden status	Output

Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_SHOW

2.2.4 FBIOSET_SHOW¶

Function

Show or hide the overlay

Syntax

int ioctl (int fd, FBIOSET_SHOW, MI_BOOL *bShow);

Description

Use this interface to set the overlay display status: show or hide

Parameter

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_SHOW	ioctl cmd	Input
bShow	Display status of the overlay: bShow = MS_TRUE: Show the current overlay bShow = MS_FALSE: Hide the current overlay	Input

Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_SHOW

2.2.5 FBIOGET_GLOBAL_ALPHA¶

Function

Get overlay Alpha setting

Syntax

int ioctl (int fd, FBIOGET_GLOBAL_ALPHA, MI_FB_GlobalAlpha_t *pstAlpha);

Description

Use this interface to get current overlay Alpha setting
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_GLOBAL_ALPHA ioctl cmd Input

pstAlpha Pointer to MI_FB_GlobalAlpha_t structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_GLOBAL_ALPHA

2.2.6 FBIOSET_GLOBAL_ALPHA¶

Function

Set overlay Alpha

Syntax

int ioctl (int fd, FBIOSET_GLOBAL_ALPHA, MI_FB_GlobalAlpha_t *pstAlpha);

Description

Use this interface to set current overlay Alpha function
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOSET_GLOBAL_ALPHA ioctl cmd Input

pstAlpha Pointer to MI_FB_GlobalAlpha_t structure Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_GLOBAL_ALPHA

2.2.7 FBIOGET_COLORKEY¶

Function

Get overlay colorkey

Syntax

int ioctl (int fd, FBIOGET_COLORKEY, MI_FB_ColorKey_t *pstColorKey);

Description

Use this interface to get overlay colorkey
Parameter

Parameter Name Description Input/Output

Fd Framebuffer device file descriptor Input

FBIOGET_COLORKEY ioctl cmd Input

pstColorKey Pointer to MI_FB_ColorKey_t structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_COLORKEY

2.2.8 FBIOSET_COLORKEY¶

Function

Set the overlay colorkey

Syntax

int ioctl (int fd, FBIOSET_COLORKEY, MI_FB_ColorKey_t *pstColorKey);

Description

Use this interface to set current overlay colorkey function
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOSET_COLORKEY ioctl cmd Input

pstColorKey Pointer to MI_FB_ColorKey_t structure Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_COLORKEY

2.2.9 FBIOSET_DISPLAYLAYER_ATTRIBUTES¶

Function

Set graphic layer information

Syntax

int ioctl (int fd, FBIOSET_DISPLAYLAYER_ATTRIBUTES, MI_FB_DisplayLayerAttr_t *pstLayerInfo);

Description

This interface is used to set graphic layer information, including screen display position, canvas resolution, memory resolution, screen display resolution, and capability of pre-multiplication of the graphic layer. For more details, see description with respect to MI_FB_DisplayLayerAttr_t.

Parameter

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_DISPLAYLAYER_ATTRIBUTES	ioctl cmd	Input
pstLayerInfo	Pointer to MI_FB_DisplayLayerAttr_t structure	Output

Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_DISPLAYLAYER_ATTRIBUTES

2.2.10 FBIOGET_DISPLAYLAYER_ATTRIBUTES¶

Function

Get graphic layer information

Syntax

int ioctl (int fd, FBIOGET_DISPLAYLAYER_ATTRIBUTES, MI_FB_DisplayLayerAttr_t *pstLayerInfo);

Description

Used to get graphic layer information, including screen display position, memory resolution, screen display resolution, and capability of pre-multiplication of the graphic layer.
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_DISPLAYLAYER_ATTRIBUTES ioctl cmd Input

pstLayerInfo Pointer to graphic layer structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_DISPLAYLAYER_ATTRIBUTES

2.2.11 FBIOGET_CURSOR_ATTRIBUTE¶

Function

Get cursor graphic layer information

Syntax

int ioctl (int fd, FBIOGET_CURSOR_ATTRIBUTE, MI_FB_CursorAttr_t *pstCursorAttr)

Description

Get cursor graphic layer information, including hotspot, position, Alpha, Colorkey, and visibility.
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_CURSOR_ATTRIBUTE ioctl cmd Input

pstCursorAttr Pointer to MI_FB_CursorAttr_t structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_CURSOR_ATTRIBUTE

2.2.12 FBIOSET_CURSOR_ATTRIBUTE¶

Function

Set cursor graphic layer information

Syntax

int ioctl (int fd, FBIOSET_CURSOR_ATTRIBUTE, MI_FB_CursorAttr_t *pstCursorAttr)

Description

Set cursor graphic layer information, including hotspot, position, Alpha, Colorkey, and visibility
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOSET_CURSOR_ATTRIBUTE ioctl cmd Input

pstCursorAttr Pointer to MI_FB_CursorAttr_t structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_CURSOR_ATTRIBUTE

2.2.13 FBIOGET_COMPRESSIONINFO¶

Function

Get compressed information

Syntax

int ioctl (int fd, FBIOGET_COMPRESSIONINFO, MI_FB_Compression_t *pstCompression)

- Note

**This interface is supported only by Opera chips**

Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOGET_COMPRESSIONINFO ioctl cmd Input

pstCompression MI_FB_Compression_t structure Output
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOSET_COMPRESSIONINFO

2.2.14 FBIOSET_COMPRESSIONINFO¶

Function

Set Compressed Information

Syntax

int ioctl (int fd, FBIOSET_COMPRESSIONINFO, MI_FB_Compression_t *pstCompression)

Note

This interface is supported only by Opera chips
Parameter

Parameter Name Description Input/Output

fd Framebuffer device file descriptor Input

FBIOSET_COMPRESSIONINFO ioctl cmd Input

pstCompression MI_FB_Compression_t structure Input
Return Value
- 0: Successful
- -1: Failed
Requirement
- Header file: mi_fb_datatype.h
Related Interface

FBIOGET_COMPRESSIONINFO

2.3. MI_FB API¶

2.3.1 MI_FB_Open¶

Function

The function is the same as open framebuff device node.
Syntax
```
MI_S32 MI_FB_Open (MI_U32 u32FbId);
```
Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a

Example

MI_S32 s32Ret = MI_SUCCESS;
MI_U32 u32FbId = 0;
void *framebuff = NULL;
MI_U32 u32ScreenSize;
MI_FB_VarScreenInfo_t stVarScreenInfo;
MI_FB_FixScreenInfo_t stFixScreenInfo;

memset(&stVarScreenInfo, 0, sizeof(MI_FB_VarScreenInfo_t));
memset(&stFixScreenInfo, 0, sizeof(MI_FB_FixScreenInfo_t));

s32Ret = MI_FB_Open(u32FbId);
if(MI_SUCCESS == s32Ret)
{
    MI_FB_GetFixScreenInfo(u32FbId, &stFixScreenInfo);
    MI_FB_GetVarScreenInfo(u32FbId, &stVarScreenInfo);
    u32ScreenSize = stFixScreenInfo.u32SmemLen;
    if(u32ScreenSize)
    MI_FB_Mmap(u32FbId, u32ScreenSize, &framebuff);
    if(framebuff)
    {
        draw(x, y, framebuff);
        stVarScreenInfo.u32Xoffset = 0;
        stVarScreenInfo.u32Yoffset = stVarScreenInfo.u32Yres;
        MI_FB_PanDisplay(u32FbId, &stVarScreenInfo);
    }
    MI_FB_Close(u32FbId);
}

Related Interface

MI_FB_Close

2.3.2 MI_FB_Close¶

Function

The function is the same as close framebuff device node.
Syntax
```
MI_S32 MI_FB_Close (MI_U32 u32FbId);
```
Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a
Related Interface

MI_FB_Open

2.3.3 MI_FB_Mmap¶

Function

The function is the same as framebuff mmap.

Syntax

MI_S32 MI_FB_Mmap (MI_U32 u32FbId, MI_U32 u32size, void **pVirAddr);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

u32size buff size Input

pVirAddr Return the mapped virtual address Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a

2.3.4 MI_FB_Munmap¶

Function

The function is the same as framebuff munmap.

Syntax

MI_S32 MI_FB_Munmap (MI_U32 u32FbId, void *pVirAddr, MI_U32 u32Size);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pVirAddr Mapped virtual address Input

u32Size buff size Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a

2.3.5 MI_FB_GetVarScreenInfo¶

Function

The function is the same as FBIOGET_VSCREENINFO.

Syntax

MI_S32 MI_FB_GetVarScreenInfo (MI_U32 u32FbId, MI_FB_VarScreenInfo_t *pstVarScreenInfo);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstVarScreenInfo Describe screen variable info Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetVarScreenInfo

FBIOGET_VSCREENINFO

2.3.6 MI_FB_SetVarScreenInfo¶

Function

The function is the same as FBIOPUT_VSCREENINFO.

Syntax

MI_S32 MI_FB_SetVarScreenInfo (MI_U32 u32FbId, MI_FB_VarScreenInfo_t *pstVarScreenInfo);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstVarScreenInfo Describe screen variable info Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetVarScreenInfo

FBIOPUT_VSCREENINFO

2.3.7 MI_FB_GetFixScreenInfo¶

Function

The function is the same as FBIOGET_FSCREENINFO.

Syntax

MI_S32 MI_FB_GetFixScreenInfo (MI_U32 u32FbId, MI_FB_FixScreenInfo_t *pstFixScreenInfo);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstFixScreenInfo Description屏幕固定信息 Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

FBIOGET_FSCREENINFO

2.3.8 MI_FB_PanDisplay¶

Function

The function is the same as FBIOPAN_DISPLAY.

Syntax

MI_S32 MI_FB_PanDisplay (MI_U32 u32FbId, MI_FB_VarScreenInfo_t *pstVarScreenInfo);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstVarScreenInfo Describe screen variable info Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

FBIOPAN_DISPLAY

2.3.9 MI_FB_WaitForVsync¶

Function

The function is the same as FBIO_WAITFORVSYNC.

Syntax

MI_S32 MI_FB_WaitForVsync (MI_U32 u32FbId);

Parameter

Parameter Description Input/Output

u32FbId FB DEVICE NUMBER Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a

2.3.10 MI_FB_GetScreenLocation¶

Function

The function is the same as FBIOGET_SCREEN_LOCATION.

Syntax

MI_S32 MI_FB_GetScreenLocation (MI_U32 u32FbId, MI_FB_Rectangle_t *pstWinRect);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstWinRect Describe the display area of the overlay on screen Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetScreenLocation

FBIOGET_SCREEN_LOCATION

2.3.11 MI_FB_SetScreenLocation¶

Function

The function is the same as FBIOSET_SCREEN_LOCATION.

Syntax

MI_S32 MI_FB_SetScreenLocation (MI_U32 u32FbId, MI_FB_Rectangle_t *pstWinRect);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstWinRect Describe the display area of the overlay on screen Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetScreenLocation

FBIOSET_SCREEN_LOCATION

2.3.12 MI_FB_GetDisplayLayerAttr¶

Function

The function is the same as FBIOGET_DISPLAYLAYER_ATTRIBUTES.

Syntax

MI_S32 MI_FB_GetDisplayLayerAttr (MI_U32 u32FbId, MI_FB_DisplayLayerAttr_t *pstDisplayLayerAttr);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstDisplayLayerAttr Describe the layer info Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetDisplayLayerAttr

FBIOGET_DISPLAYLAYER_ATTRIBUTES

2.3.13 MI_FB_SetDisplayLayerAttr¶

Function

The function is the same as FBIOSET_DISPLAYLAYER_ATTRIBUTES.

Syntax

MI_S32 MI_FB_SetDisplayLayerAttr (MI_U32 u32FbId, MI_FB_DisplayLayerAttr_t *pstDisplayLayerAttr);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstDisplayLayerAttr Describe the layer info Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetDisplayLayerAttr

FBIOSET_DISPLAYLAYER_ATTRIBUTES

2.3.14 MI_FB_GetCursorAttr¶

Function

The function is the same as FBIOGET_CURSOR_ATTRIBUTE.

Syntax

MI_S32 MI_FB_GetCursorAttr (MI_U32 u32FbId, MI_FB_CursorAttr_t *pstCursorAttr);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCursorAttr Describe the Cursor layer info Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetCursorAttr

FBIOGET_CURSOR_ATTRIBUTE

2.3.15 MI_FB_SetCursorAttr¶

Function

The function is the same as FBIOSET_CURSOR_ATTRIBUTE.

Syntax

MI_S32 MI_FB_SetCursorAttr (MI_U32 u32FbId, MI_FB_CursorAttr_t *pstCursorAttr);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCursorAttr Describe the Cursor layer info Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetCursorAttr

FBIOSET_CURSOR_ATTRIBUTE

2.3.16 MI_FB_GetGlobalAlpha¶

Function

The function is the same as FBIOGET_GLOBAL_ALPHA.

Syntax

MI_S32 MI_FB_GetGlobalAlpha (MI_U32 u32FbId, MI_FB_GlobalAlpha_t *pstAlpha);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstAlpha Describe Alpha of the overlay Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetGlobalAlpha

FBIOGET_GLOBAL_ALPHA

2.3.17 MI_FB_SetGlobalAlpha¶

Function

The function is the same as FBIOSET_GLOBAL_ALPHA.

Syntax

MI_S32 MI_FB_SetGlobalAlpha (MI_U32 u32FbId, MI_FB_GlobalAlpha_t *pstAlpha);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstAlpha Describe Alpha of the overlay Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetGlobalAlpha

FBIOSET_GLOBAL_ALPHA

2.3.18 MI_FB_GetColorKey¶

Function

The function is the same as FBIOGET_COLORKEY.

Syntax

MI_S32 MI_FB_GetColorKey (MI_U32 u32FbId, MI_FB_ColorKey_t *pstClrKey);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstClrKey Describe colorkey info of the overlay Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetColorKey

FBIOGET_COLORKEY

2.3.19 MI_FB_SetColorKey¶

Function

The function is the same as FBIOSET_COLORKEY.

Syntax

MI_S32 MI_FB_SetColorKey (MI_U32 u32FbId, MI_FB_ColorKey_t *pstClrKey);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstClrKey Describe colorkey info of the overlay Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetColorKey

FBIOSET_COLORKEY

2.3.20 MI_FB_SetCmap¶

Function

The function is the same as FBIOPUTCMAP.

Syntax

MI_S32 MI_FB_SetCmap (MI_U32 u32FbId, MI_FB_Cmap_t *pstCmap);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCmap Describe the color table info Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetCmap

2.3.21 MI_FB_GetCmap¶

Function

The function is the same as FBIOGETCMAP.

Syntax

MI_S32 MI_FB_GetCmap (MI_U32 u32FbId, MI_FB_Cmap_t *pstCmap);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCmap Describe the color table info Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetCmap

2.3.22 MI_FB_GetShow¶

Function

The function is the same as FBIOGET_SHOW.

Syntax

MI_S32 MI_FB_GetShow (MI_U32 u32FbId, MI_BOOL *pbShown);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pbShown Overlay display status Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetShow

FBIOGET_SHOW

2.3.23 MI_FB_SetShow¶

Function

The function is the same as FBIOSET_SHOW.

Syntax

MI_S32 MI_FB_SetShow (MI_U32 u32FbId, MI_BOOL bShown);

Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

bShown 1: show 0: hide Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetShow

FBIOSET_SHOW

2.3.24 MI_FB_GetCompressionInfo¶

Function

The function is the same as FBIOGET_COMPRESSIONINFO.

Syntax

MI_S32 MI_FB_GetCompressionInfo(MI_U8 u8FbId, MI_FB_Compression_t *pstCompression);

Note

This interface is supported only by Opera chips
Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCompression compression information Output
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_SetCompressionInfo

FBIOGET_COMPRESSIONINFO

2.3.25 MI_FB_SetCompressionInfo¶

Function

The function is the same as FBIOSET_COMPRESSIONINFO.

Syntax

MI_S32 MI_FB_SetCompressionInfo(MI_U8 u8FbId, MI_FB_Compression_t *pstCompression);

Note

This interface is supported only by Opera chips
Parameter

Parameter Name Description Input/Output

u32FbId FB device number Input

pstCompression Compression information Input
Return Value
- 0: Successful
- Non-zero: Failed, please refer to ERROR CODE for details
Requirement
- Header file: mi_fb.h mi_fb_datatype.h
- Library file: libmi_fb.a
Related Interface

MI_FB_GetCompressionInfo

FBIOSET_COMPRESSIONINFO

3. FB DATA TYPE¶

Data types defined in the Linux Framebuff standard:

Data type	Description
struct fb_bitfield	Bit field information for setting pixel format
struct fb_var_screeninfo	Variable screen information
struct fb_fix_screeninfo	Fixed screen information
struct fb_cmap_user	Describe the color table info

Data types defined in MI_FB:

Data type	Description
MI_FB_BitField_t	Bit field information for setting pixel format
MI_FB_VarScreenInfo_t	Variable screen information
MI_FB_FixScreenInfo_t	Fixed screen information
MI_FB_ColorFmt_e	Collection of pixel formats supported by FB
MI_FB_OuputColorSpace_e	Color space output by FB overlay
MI_FB_DstDisplayPlane_e	The target module that FB overlay output to display chain
MI_FB_DisplayLayerAttrMaskBit_e	Specify the attributes to be updated in MI_FB_DisplayLayerAttr_t
MI_FB_CursorAttrMaskBit_e	Specify the attributes to be updated in MI_FB_CursorAttr_t
MI_FB_DisplayLayerAttr_t	Describe overlay attribute info
MI_FB_AlphaMode_e	Define alpha mode
MI_FB_GlobalAlpha_t	Alpha information structure
MI_FB_ColorKey_t	Colorkey information structure
MI_FB_CursorImage_t	Describe cursor icon data info
MI_FB_CursorAttr_t	Describe Cursor layer info
MI_FB_Rectangle_t	Describe the overlay display area
MI_FB_Cmap_t	Describe the color table info
MI_FB_Compression_t	Describe the compressed information

Note: For data types not listed, please refer to mi_fb_datatype.h

3.1. Standard Data Type¶

3.1.1 struct fb_bitfield¶

Description

Bit field information for setting pixel format

Definition

struct fb_bitfield
{
    __u32 offset;    /* beginning of bitfield */
    __u32 length;    /* length of bitfield */
    __u32 msb_right;    /* != 0: Most significant bit is right */
};

Member

Member	Description	Supportability
offset	Color component start bit	Supported
length	Length of the bit occupied by the color component	Supported
msb_right	Whether the bit on the right is the most significant bit.	Only 0 is supported. That is, the leftmost bit is the most significant bit.

3.1.2 struct fb_var_screeninfo¶

Description

Variable screen information

Definition

struct fb_var_screeninfo
{
    __u32 xres;    /* visible resolution */
    __u32 yres;
    __u32 xres_virtual;    /* virtual resolution */
    __u32 yres_virtual;
    __u32 xoffset;    /* offset from virtual to visible */
    __u32 yoffset;    /* resolution */

    __u32 bits_per_pixel;    /* guess what */
    __u32 grayscale;    /* != 0 Graylevels instead of colors */
    struct fb_bitfield red;    /* bitfield in fb mem if true color, */ struct fb_bitfield green;    /* else only length is significant */ struct fb_bitfield blue;
    struct fb_bitfield transp; /* transparency */

    __u32 nonstd;    /* != 0 Non standard pixel format */

    __u32 activate;    /* see FB_ACTIVATE_* */

    __u32 height;    /* height of picture in mm */
    __u32 width;    /* width of picture in mm */

    __u32 accel_flags;    /* (OBSOLETE) see fb_info.flags */

    /* Timing: All values in pixclocks, except pixclock (of course) */
    __u32 pixclock;    /* pixel clock in ps (pico seconds) */
    __u32 left_margin;    /* time from sync to picture */
    __u32 right_margin;    /* time from picture to sync */
    __u32 upper_margin;    /* time from sync to picture */
    __u32 lower_margin;
    __u32 hsync_len;    /* length of horizontal sync */
    __u32 vsync_len;    /* length of vertical sync */
    __u32 sync;    /* see FB_SYNC_* */
    __u32 vmode;    /* see FB_VMODE_* */
    __u32 rotate;    /* angle we rotate counter clockwise */
    __u32 reserved[5];    /* Reserved for future compatibility */
};

Member

Member	Description	Supportability
xres	Visible screen width (number of pixels)	Supported
yres	Visible screen height (number of pixels)	Supported
xres_virtual	Virtual screen width (image width in memory). When the value is smaller than xres, xres will be modified to be equal to that value.	Supported
yres_virtual	Virtual screen height (image height in memory). When the value is smaller than yres, yres will be modified to be equal to that value. If used in combination with xres_virtual, this parameter can pan image quickly in horizontal or vertical direction.	Supported
xoffset	Number of offset pixels in x direction	Supported, default is 0
yoffset	Number of offset pixels in y direction	Supported, default is 0
bits_per_pixel	Number of bits occupied by each pixel	Supported
grayscale	Grayscale	Not supported, default is 0 (color)
red	Red bit field information in the color component	Supported
green	Green bit field information in the color component	Supported
blue	Blue bit field information in the color component	Supported
transp	Alpha bit field information in the color component	Supported
nonstd	Indicates whether standard pixel format is used	Not supported, default is 0 (standard pixel format supported)
activate	Set the time of activation	Not supported, default is FB_ACTIVATE_NOW (activated immediately)
height	Screen height, unit is mm	Not supported, default is -1
width	Screen width, unit is mm	Not supported, default is -1
accel_flags	Acceleration flag	Not supported, default is -1
pixclock	Time required to show a pixel, unit is ns	Not supported, default is -1
left_margin	Represent the left blanking signal, the right blanking signal, and the horizontal synchronization duration. The sum of these values is equal to the horizontal retrace time in unit of dot clock.	Not supported, default is 64
right_margin
hsync_len
upper_margin	Represent the upper blanking signal, the lower blanking signal, and the vertical synchronization duration. The sum of these values is equal to the vertical retrace time in unit of dot clock.	Not supported, default is -1
lower_margin
vsync_len
sync	Signal synchronization method	Not supported, default is -1
vmode	Scan mode	Not supported, default is -1
rotate	Angle of rotation clockwise	Not supported, default is 0 (no rotation)

Note

The default resolution of the HD device graphics layer is 1280x720; the default resolution of the SD device graphics layer is 720x576, and the cursor layer default resolution is 128x128. The pixel format is ARGB1555.
Related Data Type and Interface

struct fb_bitfield

FBIOGET_VSCREENINFO

FBIOPUT_VSCREENINFO

3.1.3 struct fb_fix_screeninfo¶

Description

Fixed screen information

Definition

struct fb_fix_screeninfo
{
    char id[16];  /* identification string eg "TT Builtin" */
    unsigned long smem_start;    /* Start of frame buffer mem (physical address) */
    __u32 smem_len;    /* Length of frame buffer mem */
    __u32 type;    /* see FB_TYPE_* */
    __u32 type_aux;    /* Interleave for interleaved Planes */
    __u32 visual;    /* see FB_VISUAL_* */
    __u16 xpanstep;    /* zero if no hardware panning */
    __u16 ypanstep;    /* zero if no hardware panning */
    __u16 ywrapstep;    /* zero if no hardware ywrap */
    __u32 line_length;    /* length of a line in bytes */
    unsigned long mmio_start;    /* Start of Memory Mapped I/O (physical address) */
    __u32 mmio_len;    /* Length of Memory Mapped I/O */
    __u32 accel; /* Indicate to driver which specific chip/card we have */
    __u16 reserved[3];    /* Reserved for future compatibility */
};

Member

Member	Description	Supportability
id	Device driver name	Supported
smem_start	Memory start physical address	Supported
smem_len	Memory size	Supported
type	Graphics card type	Fixed to FB_TYPE_PACKED_PIXELS(pixel values closely packed)
type_aux	Auxiliary type	Not supported. Undefined graphics card type under FB_TYPE_PACKED_PIXELS.
visual	Color mode	Not supported, default is FB_VISUAL_TRUECOLOR (true color)
xpanstep	Support horizontal PAN display or not: 0: Not supported ǂ 0: Supported. The value in this case is used to indicate the pixel value per step in the horizontal direction	Fixed to 1
ypanstep	Support vertical PAN display or not: 0: Not supported ǂ 0: Supported. The value in this case is used to indicate the pixel value per step in the vertical direction	Fixed to 1
ywrapstep	Smilar to ypanstep, except that when it is displayed to the bottom, it can be returned to the beginning of the video memory for display.	Not supported, default is 0
line_length	Number of bytes per line	Supported
mmio_start	Memory map I/O start address	Not supported, default is 0
mmio_len	Memory map I/O length	Not supported, default is 0
accel	Indicate the hardware acceleration device supported	Not supported, default is FB_ACCEL_NONE (no acceleration)
reserved	Reserved	Not supported, default is 0

Related Data Type and Interface

FBIOGET_FSCREENINFO

3.1.4 struct fb_cmap_user¶

Description

Describe the color table info。

Definition

struct fb_cmap_user
{
    __u32 start;    /* First entry */
    __u32 len;    /* Number of entries */
    __u32 __user *red;    /* Red values */
    __u32 __user *green;
    __u32 __user *blue;
    __u32 __user *transp;    /* transparency, can be NULL*/
};

Member

Member	Description	Supportability
start	Entry of the first element	Supported
len	Number of elements	Supported
red	Red component start position	Supported
green	Green component start position	Supported
blue	Blue component start position	Supported
transp	Transparency component start position	Supported

3.2. MI_FB Data Type¶

3.2.1 MI_FB_BitField_t¶

Description

Bit field information for setting pixel format
Related Data Type and Interface

MI_FB_GetVarScreenInfo

MI_FB_SetVarScreenInfo

3.2.2 MI_FB_VarScreenInfo_t¶

Description

Variable screen information
Related Data Type and Interface

MI_FB_GetVarScreenInfo

MI_FB_SetVarScreenInfo

3.2.3 MI_FB_FixScreenInfo_t¶

Description

Fixed screen information
Related Data Type and Interface

MI_FB_GetFixScreenInfo

3.2.4 MI_FB_ColorFmt_e¶

Description

Collection of pixel formats supported by FB.

Definition

typedef enum
{
    E_MI_FB_COLOR_FMT_RGB565            = 1,
    E_MI_FB_COLOR_FMT_ARGB4444          = 2,
    E_MI_FB_COLOR_FMT_I8                 = 4,
    E_MI_FB_COLOR_FMT_ARGB8888          = 5,
    E_MI_FB_COLOR_FMT_ARGB1555          = 6,
    E_MI_FB_COLOR_FMT_YUV422             = 9,
    E_MI_FB_COLOR_FMT_I4                  = 13,
    E_MI_FB_COLOR_FMT_I2                  = 14,
    /// Invalid color format.
    E_MI_FB_COLOR_FMT_INVALID
}MI_FB_ColorFmt_e;

Member

Member	Description
E_MI_FB_COLOR_FMT_RGB565	RGB565 format
E_MI_FB_COLOR_FMT_ARGB4444	ARGB444 format
E_MI_FB_COLOR_FMT_I8	I8
E_MI_FB_COLOR_FMT_ARGB8888	ARGB8888 format
E_MI_FB_COLOR_FMT_ARGB1555	ARGB1555 format
E_MI_FB_COLOR_FMT_YUV422	YUV422 format
E_MI_FB_COLOR_FMT_I4	I4
E_MI_FB_COLOR_FMT_I2	I2
E_MI_FB_COLOR_FMT_INVALID	Invalid pixel format

Related Data Type and Interface

MI_FB_DisplayLayerAttr_t

3.2.5 MI_FB_OuputColorSpace_e¶

Description

FBColor space output by FB overlay

Definition

typedef enum
{
    E_MI_FB_OUTPUT_RGB = 0,
    E_MI_FB_OUTPUT_YUV = 1
}MI_FB_OutputClrSpace_e;

Member

Member name Description

E_MI_FB_OUTPUT_RGB RGB ColorSpace

E_MI_FB_OUTPUT_YUV YUV ColorSpace
Related Data Type and Interface

MI_FB_DisplayLayerAttr_t

3.2.6 MI_FB_DstDisplayPlane_e¶

Description

The target module that FB overlay output to display chain, which can select the image adjustment process that the overlay participates in by configuring different display chain.

Definition

typedef enum
{
    E_MI_FB_DST_IP0 = 0,
    E_MI_FB_DST_IP0_SUB = 1,
    E_MI_FB_DST_MIXER2VE = 2,
    E_MI_FB_DST_OP0 = 3,
    E_MI_FB_DST_VOP = 4,
    E_MI_FB_DST_IP1 = 5,
    E_MI_FB_DST_IP1_SUB = 6,
    E_MI_FB_DST_MIXER2OP = 7,
    E_MI_FB_DST_VOP_SUB = 8,
    E_MI_FB_DST_FRC = 9,
    E_MI_FB_DST_VE = 10,
    E_MI_FB_DST_BYPASS = 11,
    E_MI_FB_DST_OP1 = 12,
    E_MI_FB_DST_MIXER2OP1 = 13,
    E_MI_FB_DST_DIP = 14,
    E_MI_FB_DST_COPScaling = 15,
    E_MI_FB_DST_OP_DUAL_RATE = 16,
    E_MI_FB_DST_INVALID = 17,
}MI_FB_DstDisplayPlane_e

Member

Member name Description

E_MI_FB_DST_OP0 OP0 path

E_MI_FB_DST_OP1 OP1 path

Note: Only supports E_MI_FB_DST_OP0/E_MI_FB_DST_OP1
Related Data Type and Interface

MI_FB_DisplayLayerAttr_t

3.2.7 MI_FB_DisplayLayerAttrMaskBit_e¶

Description

Specify the attributes to be updated in MI_FB_DisplayLayerAttr_t

Definition

typedef enum
{
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_POS = 0x1,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_SIZE = 0x2,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_BUFFER_SIZE = 0x4,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_SCREEN_SIZE = 0x8,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_PREMUL = 0x10,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_COLOR_FMB = 0x20,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_OUTPUT_COLORSPACE = 0x40,
    E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_DST_DISP = 0x80,
}MI_FB_DisplayLayerAttrMaskBit_e

Member

Member	Description
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_POS	Update display position
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_SIZE	Update display range
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_BUFFER_SIZE	Update buff size
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_SCREEN_SIZE	Update screen resolution
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_PREMUL	Update premultiply alpha
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_COLOR_FMB	Update pixel format
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_OUTPUT_COLORSPACE	Update output color space
E_MI_FB_DISPLAYLAYER_ATTR_MASK_DISP_DST_DISP	Update the destination module of the overlay output to the display chain

Related Data Type and Interface

MI_FB_DisplayLayerAttr_t

3.2.8 MI_FB_CursorAttrMaskBit_e¶

Description

Specify the attributes to be updated in MI_FB_CursorAttr_t

Definition

typedef enum
{
    E_MI_FB_CURSOR_ATTR_MASK_ICON = 0x1,
    E_MI_FB_CURSOR_ATTR_MASK_POS = 0x2,
    E_MI_FB_CURSOR_ATTR_MASK_ALPHA = 0x4,
    E_MI_FB_CURSOR_ATTR_MASK_SHOW = 0x8,
    E_MI_FB_CURSOR_ATTR_MASK_HIDE = 0x10,
    E_MI_FB_CURSOR_ATTR_MASK_COLORKEY = 0x20,
    E_MI_FB_CURSOR_ATTR_MASK = 0x3F,
}MI_FB_CursorAttrMaskBit_e

Member

Member	Description
E_MI_FB_CURSOR_ATTR_MASK_ICON	Cursor icon changes
E_MI_FB_CURSOR_ATTR_MASK_POS	Cursor position changes
E_MI_FB_CURSOR_ATTR_MASK_ALPHA	Alpha changes
E_MI_FB_CURSOR_ATTR_MASK_SHOW	Show Cursor
E_MI_FB_CURSOR_ATTR_MASK_HIDE	Hide Cursor
E_MI_FB_CURSOR_ATTR_MASK_COLORKEY	Color key changes
E_MI_FB_CURSOR_ATTR_MASK	Identify all settable attributes of the Cursor

Related Data Type and Interface

MI_FB_CursorAttr_t

3.2.9 MI_FB_DisplayLayerAttr_t¶

Description

Describe overlay attribute info

Definition

typedef struct
{
    MI_U32 u32XPos;         /**the x pos of orign point in screen*/
    MI_U32 u32YPos;         /**the y pos of orign point in screen*/
    MI_U32 u32DstWidth;      /**display buffer dest with in screen*/
    MI_U32 u32DstHeight;     /**display buffer dest hight in screen*/
    MI_U32 u32DisplayWidth;  /**the width of display buf in fb */
    MI_U32 u32DisplayHeight;  /**the height of display buf in fb. */
    MI_U32 u32ScreenWidth;   /**the width of screen */
    MI_U32 u32ScreenHeight;  /** the height of screen */
    MI_BOOL bPreMul;        /**the data drawed in buffer whether is premultiply alpha or not*/
    MI_FB_ColorFmt_e eFbColorFmt;     /**the color format of framebuffer*/
    MI_FB_OutputClrSpace_e  eFbOutputColorSpace;   /**output color space*/
    MI_FB_DstDisplayPlane_e  eFbDestDisplayPlane;   /**destination displayplane*/
    MI_U32 u32DisplayInfoMask;    /** display attribute modify mask*/
}MI_FB_DisplayLayerAttr_t;

Member

Member	Description	Supportability
offset	Color component start bit	Supported
u32XPos	The X coordinate of the layer at the origin of the screen.	Supported
u32YPos	The Y coordinate of the layer at the origin of the screen.	Supported
u32DstWidth	The display width of the layer on the screen	Supported
u32DstHeight	The display height of the layer on the screen	Supported
u32DisplayWidth	The width of the video memory resolution.	Supported
u32DisplayHeight	The height of the video memory resolution.	Supported
u32ScreenWidth	The width of the screen display resolution.	Supported
u32ScreenHeight	The height of the screen display resolution.	Supported
bPreMul	Whether the data in FB is premultiplied data.	Supported
eFbColorFmt	FB pixel format.	Supported
u32SetAttrMask	When setting the layer information, the parameter modifies the mask bit.	Supported
eFbOutputColorSpace	Set the Color space of the overlay output	Supported
eFbDestDisplayPlane	Set the destination module of the overlay output to the display chain. The default is E_MI_FB_DST_OP0.	Supported

Related Data Type and Interface

MI_FB_GetDisplayLayerAttr

MI_FB_SetDisplayLayerAttr

3.2.10 MI_FB_AlphaMode_e¶

Description

Define alpha mode

Definition

typedef enum
{
    E_MI_FB_ALPHA_CHANNEL       = 0x01,
    E_MI_FB_ALPHA_INVERT        = 0x02,
    E_MI_FB_ALPHA_PREMULTIPLIED = 0x04,
    E_MI_FB_ALPHA_PLANE_ALPHA   = 0x08,
} MI_FB_AlphaMode_e;

Member

Member	Description
E_MI_FB_ALPHA_CHANNEL	Alpha mode. The alpha mode is global alpha when the bit is 0, the alpha mode is pixel alpha when the bit is 1.
E_MI_FB_ALPHA_INVERT	Alpha invert. The transparency of the screen is invert when the bit is 1.
E_MI_FB_ALPHA_PREMULTIPLIED	Pre-multiplication. The alpha blending is proccessed as premultiplied data when the bit is 1, else it will use default alpha blending.
E_MI_FB_ALPHA_PLANE_ALPHA	Plane alpha. Introduces plane alpha to alpha blending when the bit is 1.

Note
- Alpha mode
  - Global alpha: All pixel use the same alpha value to participate in alpha blending. Global alpha value is set by the member of structure MI_FB_GlobalAlpha_t.
  - Pixel alpha: The alpha value of each pixel uses the alpha value bits of pixel value to participate in alpha blending, such as the bit[31:24] of ARGB8888 pixel.
- Alpha invert: 255 - current alpha.
- Pre-multiplication: Used when user data is premultiplied data. alpha blending with special algorithms. A dedicated pre multiplication algorithm will be used when alpha blending.
- Plane alpha: Introduce user-specified plane alpha(MI_FB_GlobalAlpha_t) when alpha blending.
Related Data Type and Interface

MI_FB_GetGlobalAlpha

MI_FB_SetGlobalAlpha

3.2.11 MI_FB_GlobalAlpha_t¶

Description

Alpha information structure

Definition

typedef struct
{
    MI_U16 u8AlphaMode;
    MI_U16 u16PlaneAlpha;
    MI_U8  u8Alpha0;
    MI_U8  u8Alpha1;
    MI_U8  u8GlobalAlpha;
} MI_FB_GlobalAlpha_t;

Member

Member	Description
u8AlphaMode	Alpha mode. For the definition of bit[3:0], please refer to MI_FB_AlphaMode_e.
u16PlaneAlpha	The value of plane alpha.
u8Alpha0	Alpha0 value, the range is 0~255, the default is 255. In the RGB1:5:5:5 format, when the highest bit is 0, select this value as the Alpha superimposition value.
u8Alpha1	Alpha1 value, the range is 0~255, the default is 255. In the RGB1:5:5:5 format, when the highest bit is 1, select this value as the Alpha superimposition value.
u8GlobalAlpha	Global Alpha value, the range is 0~255, the default is 255. It takes effect when the Alpha channel is enabled.

Related Data Type and Interface

MI_FB_GetGlobalAlpha

MI_FB_SetGlobalAlpha

3.2.12 MI_FB_ColorKey_t¶

Description

Colorkey information structure.

Definition

typedef struct
{
    MI_BOOL bKeyEnable;
    MI_U8 u8Red;
    MI_U8 u8Green;
    MI_U8 u8Blue;
} MI_FB_ColorKey_t

Member

Member Description

bKeyEnable Colorkey enable.
TRUE: Enable
FALSE: Not enable

u8Red Colorkey R component value

u8Green Colorkey G component value

u8Blue Colorkey B component value

Note

RGB555/RGB444/RGB565 needs to be converted to RGB888 format. I2/I4/I8 needs to follow the palette table to set colorkey.
Conversion rules：The highest bit of each component fills the lowest bit up to 8 bits.
- Take RGB565 converts to RGB888 as an example:
  - The R component accounts for 5 bits：R4 R3 R2 R1 R0, completes 8bits: R4 R3 R2 R1 R0 R4 R3 R2
  - The G component accounts for 6 bits：G5 G4 G3 G2 G1 G0，completes 8bits: G5 G4 G3 G2 G1 G0 G5 G4
  - The B component accounts for 5 bits：B4 B3 B2 B1 B0，completes 8bits: B4 B3 B2 B1 B0 B4 B3 B2

convert function

/**
*  Convert the value of colorkey according to the color format.
*  @eFmt: color format.
*  @u32ColorKeyVal: the colorkey value before conversion, input paramter.
*  @stColorKey: the colorkey value after conversion, output paramter.
*/
void convertColorkeyVal(MI_FB_ColorFmt_e eFmt, MI_U32 u32ColorKeyVal, MI_FB_ColorKey_t *pstColorKey)
{
    MI_U8 *pu8R =  &pstColorKey->u8Red;
    MI_U8 *pu8G =  &pstColorKey->u8Green;
    MI_U8 *pu8B =  &pstColorKey->u8Blue;
    switch (eFmt)
    {
        case E_MI_FB_COLOR_FMT_ARGB1555:
        {
            *pu8R = ((u32ColorKeyVal & 0xFFFF) & 0x7C00) >> 10;
            *pu8G = ((u32ColorKeyVal & 0xFFFF) & 0x3E0) >> 5;
            *pu8B = (u32ColorKeyVal & 0xFFFF) & 0x1F;
            *pu8R = *pu8R << 3 | ((*pu8R & 0x1C) >> 2);
            *pu8G = *pu8G << 3 | ((*pu8G & 0x1C) >> 2);
            *pu8B = *pu8B << 3 | ((*pu8B & 0x1C) >> 2);
        }
        break;
        case E_MI_FB_COLOR_FMT_ARGB4444:
        {
            *pu8R = ((u32ColorKeyVal & 0xFFFF) & 0xF00) >> 8;
            *pu8G = ((u32ColorKeyVal & 0xFFFF) & 0xF0) >> 4;
            *pu8B = (u32ColorKeyVal & 0xFFFF) & 0xF;
            *pu8R = (*pu8R << 4) | *pu8R;
            *pu8G = (*pu8G << 4) | *pu8G;
            *pu8B = (*pu8B << 4) | *pu8B;
        }
        break;
        case E_MI_FB_COLOR_FMT_RGB565:
        {
            *pu8R = ((u32ColorKeyVal & 0xFFFF) & 0xF800) >> 11;
            *pu8G = ((u32ColorKeyVal & 0xFFFF) & 0x7E0) >> 5;
            *pu8B = (u32ColorKeyVal & 0xFFFF) & 0x1F;
            *pu8R = (*pu8R << 3) | ((*pu8R & 0x1C) >> 2);
            *pu8G = (*pu8G << 2) | ((*pu8G & 0x30) >> 4);
            *pu8B = (*pu8B << 3) | ((*pu8B & 0x1C) >> 2);
        }
        break;
        case E_MI_FB_COLOR_FMT_I2:
        case E_MI_FB_COLOR_FMT_I4:
        case E_MI_FB_COLOR_FMT_I8:
        case E_MI_FB_COLOR_FMT_ARGB8888:
        {
            *pu8R = ((u32ColorKeyVal) & 0xFF0000) >> 16;
            *pu8G = ((u32ColorKeyVal) & 0xFF00) >> 8;
            *pu8B = (u32ColorKeyVal) & 0xFF;
        }
        break;
        default:
        {
            printf("unsupport color format\n");
        }
    }
}

Related Data Type and Interface

MI_FB_GetColorKey

MI_FB_SetColorKey

3.2.13 MI_FB_CursorImage_t¶

Description

Describe cursor icon data info

Definition

typedef struct
{
    MI_U32 u32Width;     /**width, unit pixel*/
    MI_U32 u32Height;    /**Height, unit pixel*/
    MI_U32 u32Pitch;     /**Pitch, unit pixel*/
    MI_FB_ColorFmt_e eColorFmt;   /**Color format*/
    const char *pData;
}MI_FB_CursorImage_t;

Member

Member Description

u32Width Icon width

u32Height Icon height

u32Pitch pitch

eColorFmt Icon data pixel format

pData Icon data
Related Data Type and Interface

MI_FB_CursorAttr_t

3.2.14 MI_FB_CursorAttr_t¶

Description

Describe Cursor layer info

Definition

typedef struct
{
    MI_U32 u32XPos;
    MI_U32 u32YPos;
    MI_U32 u32HotSpotX;
    MI_U32 u32HotSpotY;
    MI_FB_GlobalAlpha_t stAlpha;
    MI_FB_ColorKey_t stClrKey;
    MI_BOOL bShown;
    MI_FB_CursorImage_t stCursorImageInfo;
    MI_U16 u16CursorInfoMask;
}MI_FB_CursorAttr_t;

Member

Member	Description
u32XPos	X coordinate of Cursor position
u32YPos	Y coordinate of Cursor position
u32HotSpotX	Cursor hotspot X coordinate
u32HotSpotY	Cursor hotspot Y coordinate
stAlpha	MI_FB_GlobalAlpha_t, Cursor layer alpha info
stColorKey	MI_FB_ColorKey_t, Cursor layer colorkey info
bShown	Whether the Cursor is visible TRUE: visible FALSE: invisible
MI_FB_CursorImage_t	Icon data info.
u16CursorInfoMask	Set the Cursor layer parameters to modify the mask bit

Related Data Type and Interface

MI_FB_GetCursorAttr

MI_FB_SetCursorAttr

3.2.15 MI_FB_Rectangle_t¶

Description

Describe the overlay display area

Definition

typedef struct
{
    MI_U32 u32XPos;
    MI_U32 u32YPos;
    MI_U32 u32Width;
    MI_U32 u32Height;
}MI_FB_Rectangle_t;

Member

Member	Description
u32XPos	X coordinate of Cursor position
u32YPos	Y coordinate of Cursor position
u32HotSpotX	Cursor hotspot X coordinate
u32HotSpotY	Cursor hotspot Y coordinate
stAlpha	MI_FB_GlobalAlpha_t, Cursor layer alpha info
stColorKey	MI_FB_ColorKey_t, Cursor layer colorkey info
bShown	Whether the Cursor is visible TRUE: visible FALSE: invisible
MI_FB_CursorImage_t	Icon data info.
u16CursorInfoMask	Set the Cursor layer parameters to modify the mask bit

Related Data Type and Interface

MI_FB_GetScreenLocation

MI_FB_SetScreenLocation

3.2.16 MI_FB_Cmap_t¶

Description

Describe the color table info
Related Data Type and Interface

MI_FB_SetCmap

MI_FB_GetCmap

3.2.17 MI_FB_Compression_t¶

Description

Describes the compressed information structure diagram, supported only by the Opera chip

Definition

typedef struct
{
    MI_BOOL          bEnable;
    MI_BOOL          bBlockSplit;
    MI_BOOL          bColorTransform;
    MI_FB_ColorFmt_e eColorFmt;
    MI_U16           u16Width;
    MI_U16           u16Height;
} MI_FB_Compression_t

Member

Member	描述	Supportability
bEnable	compressed enable mark. TRUE: Enable; FALSE: Disable.	Supported
bBlockSplit	block split enable mark. TRUE: Enable; FALSE: Disable.	Supported
bColorTransform	color transform enable mark. TRUE: Enable; FALSE: Disable.	Supported
eColorFmt	color format	Supported
u16Width	compressed width	Supported
u16Height	compressed height	Supported

Related Data Type and Interface

MI_FB_GetCompressionInfo

MI_FB_SetCompressionInfo

4. ERROR CODE¶

Error Code	Macro Definition	Description
0x0	MI_SUCCESS	Success
0xA00A2001	MI_ERR_FB_INVALID_DEVID	Invalid device id
0xA00A2003	MI_ERR_FB_INVALID_PARAM	Invalid parameter
0xA00A2004	MI_ERR_FB_EXIST	Repeated operation
0xA00A2005	MI_ERR_FB_UNEXIST	No target
0xA00A2006	MI_ERR_FB_NULL_PTR	Null pointer
0xA00A2007	MI_ERR_FB_NOT_CONFIG	No config
0xA00A2008	MI_ERR_FB_NOT_SUPPORT	No support
0xA00A200C	MI_ERR_FB_NOMEM	Memory not enough
0xA00A2011	MI_ERR_FB_BADADDR	Address error
0xA00A2013	MI_ERR_FB_BUSY	Device busy

5. PROCFS INTRODUCTION¶

5.1. cat¶

Debug info

/ # cat /proc/mi_modules/mi_fb/mi_fb0

#####################################[ Start dump fb ]#####################################

==============================[ Start dump MI_FB module info ]==============================
Frame buffer disp path: disable
Frame buffer video path: disable

default_reserved_mem_name: "fb"
===============================[ End dump MI_FB module info ]===============================

==========================================[ FB 0 ]==========================================
Framebuffer id=FB0
open count:1
fix.smem_start=0x1b600000    fix.smem_length=8519680
fix.line_length=1024    colorFmt=ARGB1555
xres=512    yres=300
xres_virtual=512    yres_virtual=8320
xoffset=0    yoffset=0
Show=TRUE    Output Space=RGB
ScreenLocation Info ==>    Pos=[512, 0]    Size=[512, 300]
Alpha Info ==>    Channel=1    Invert=(null)    PreMultiplied=0    Plane=0
                  GlobalAlphaValue=0xff    Alpha0=0x0    Alpha1=0xff    PlaneAlpha=0x0
ColorKey Info ==>    Enable=0    ColorKey Value=[0x0, 0x0, 0x0]
-------------------------------------[ Dump Gop Info ]-------------------------------------
Gop ID=2
Gwin ID=0
StretchWindow Info ==>    Pos=[0, 0]    Src=[1024, 600]    Dst=[1024, 600]
Gwin Info ==>    Pos=[512, 0]    Size=[512, 300]    colorFmt=6    pitch=1024    phyAddr:0x1b600000
Current timing=[1024, 600]

-------------------------------------[ Dump Gop Info ]-------------------------------------
Path=[34, 1, 0, 0]
Gwin ID=7
Canvas Info ==>    Pos=[0, 0]    Size=[960, 540]    colorFmt=0    Stride=1920    phyAddr=0x1a6fd200

++++++++++++++++++++++++++++++++++++++++[ CURSOR 0 ]++++++++++++++++++++++++++++++++++++++++
Init=0    Show=FALSE
Icon Size=[32, 32]
Icon Pos=[128, 255]    Hotspot=[0, 0]
Alpha Info ==>    Channel=1    Invert=(null)    PreMultiplied=0    Plane=0
                  GlobalAlphaValue=0x0    Alpha0=0x0    Alpha1=0xff    PlaneAlpha=0xff
ColorKey Info ==>    Enable=0    ColorKey Value=[0x0, 0x0, 0x0]
-------------------------------------[ Dump Gop Info ]-------------------------------------
Gop ID=2
Gwin ID=1
StretchWindow Info ==>    Pos=[0, 0]    Src=[1024, 600]    Dst=[1024, 600]
Gwin Info ==>    Pos=[128, 255]    Size=[32, 32]    colorFmt=0    pitch=64    phyAddr:0x1b700000

######################################[ End dump fb ]######################################

Debug info analysis

Record the current Fbdev and Hwcursor usage status and OSD layer/OSD device/Hwcursor attributes, and can dynamically obtain information, which is convenient for debugging and testing.

Parameter Description

Parameter			Description
MI_FB module info	Frame buffer disp path		Whether to support video preview overlay
	Frame buffer video path		Whether to support video processing overlay
	default_reserved_mem_name		Bootlogo reserved memory name
MI_FB UI device info	Framebuffer id		Framebuffer device ID
	open count		Open count
	fix.smem_start		Framebuffer physical address
	fix.smem_length		Framebuffer size (unit: byte)
	fix.line_length		Framebuffer line length (unit: byte)
	colorFmt		Framebuffer color format
	xres		Visible resolution width
	yres		Visible resolution height
	xres_virtual		Virtual resolution width
	yres_virtual		Virtual resolution height
	xoffset		X offset from visible resolution to virtual resolution
	yoffset		Y offset from visible resolution to virtual resolution
	Show		Framebuffer UI show flag
	Output space		The color space of the layer output. Value: YUV means Output YUV color space; RGB means Output RGB color space. Default value: YUV.
	ScreenLocation Info	Pos	Framebuffer UI's starting coordinate relative to the screen
	ScreenLocation Info	Size	Framebuffer UI's width and height occupied the number of pixels on the screen
	Alpha Info	Channel	UI Alpha type. Value: 0 means Global alpha; 1 means Pixel alpha
		Invert	UI Alpha invert or not
		PreMultiplied	UI alpha blending with PreMultiplied or not
		Plane	UI alpha blending introduce plane or not
		GlobalAlphaValue	Global alpha value
		Alpha0	In ARGB1555 format, when the highest bit is 0, the actual alpha of the pixel.
		Alpha1	In ARGB1555 format, when the highest bit is 1, the actual alpha of the pixel.
		PlaneAlpha	Plane alpha value
	ColorKey Info	Enable	Colorkey enable
	ColorKey Info	ColorKey value	ColorKey RGB value of the color.
MI_FB UI Gop info(video preview overlay)	Gop ID		Hardware ID of the layer
	Gwin ID		Hardware display window ID of the layer
	StretchWindow Info	Pos	The starting coordinates of the stretch window
		Src	The source size of stretch window
		Dst	The destination size of stretch window
	Gwin Info	Pos	The starting coordinates of hardware display window
		Size	The size of hardware display window
		colorFmt	The color format of hardware display window
		pitch	The line length of hardware display window (unit: byte)
		phyAddr	The physical address of hardware display window
	Current timing		Screen resolution
MI_FB UI Rgn info (Video processing overlay)	Path		Video processing unit's [Modid, Devid, Chnid, OutPortid]
	Gwin ID		Hardware display window ID of the layer
	Canvas Info	Pos	UI's starting coordinates of screen
		Size	UI's width and height occupied the number of pixels on the screen
		colorFmt	UI color format
		Stride	UI line length (unit: byte)
		phyAddr	UI physical starting address
MI_FB CURSOR device info	Init		Cursor initialized flag
	Show		Cursor show flag
	Icon Size		Cursor icon size
	Icon Pos		The starting coordinates of cursor icon
	Hotspot		Cursor hotspot information
	Alpha Info	Channel	Cursor alpha type. Value: 0 means Global alpha, 1 means Pixel alpha
		Invert	Cursor alpha invert or not
		PreMultiplied	Cursor alpha blending with PreMultiplied or not
		Plane	Cursor UI alpha blending introduce plane or not
		GlobalAlphaValue	Global alpha value
		Alpha0	In ARGB1555 format, when the highest bit is 0, the actual alpha of the pixel.
		Alpha1	In ARGB1555 format, when the highest bit is 1, the actual alpha of the pixel.
		PlaneAlpha	Plane alpha value
	ColorKey Info	Enable	Colorkey enable
	ColorKey Info	ColorKey value	ColorKey RGB value of the color.
MI_FB CURSOR Gop info	Gop ID		Hardware ID of the layer
	Cursor Gwin ID		Hardware display window ID of the layer
	StretchWindow Info	Pos	The starting coordinates of the stretch window
		Src	The source size of stretch window
		Dst	The destination size of stretch window
	Gwin Info	Pos	The starting coordinates of hardware display window
		Size	The size of hardware display window
		colorFmt	The color format of hardware display window
		pitch	The line length of hardware display window (unit: byte)
		phyAddr	The physical starting address of hardware display window

5.2. echo¶

Function	Turn on or off ui layer or cursor layer
Command	echo SHOW [Layer] [enable] > /proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[Layer] fb hierarchy ，GUI:ui layer；CURSOR:cursor layer. [enable] on / off
Example	echo SHOW GUI on > /proc/mi_modules/mi_fb/mi_fb0 Turn on the layer ui echo SHOW CURSOR off > /proc/mi_modules/mi_fb/mi_fb0 Turn off the layer cursor

Function	Set or unset mask PanDispley
Command	echo MASK_PAN [enable] > /proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[enable] on / off
Example	echo MASK_PAN on > /proc/mi_modules/mi_fb/mi_fb0 set PanDispley mask echo MASK_PAN off > /proc/mi_modules/mi_fb/mi_fb0 unset PanDispley mask

Function	Set Colorkey for the ui layer or cursor layer
Command	echo COLORKEY [Layer] [enable] [R] [G] [B] > /proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[Layer] fb hierarchy ，GUI:ui layer；CURSOR:cursor layer. [enable] on / off. [Red] Red component, hex , in ARGB888 format. [Green] Green component, hex, in ARGB888 format. [Blue] Blue component, hex, in ARGB888 format.
Example	echo COLORKEY GUI on ff 00 00 > /proc/mi_modules/mi_fb/mi_fb0 Set the Colorkey of ui layer to red.

Function	Dump the current displayed cursor icon
Command	echo DUMP_CURSOR [filePath] >/proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[filePath] Path to save dump data
Example	echo DUMP_CURSOR /mnt > /proc/mi_modules/mi_fb/mi_fb0 Dump cursor icon to /mnt, the file name is CursorData.raw, open with 7yuv, set the width and height to 128, and display Rawdata according to the cursor format setting.

Function	Set the pixel alpha value for ARGB1555 format on ui layer or cursor layer respectively.
Command	echo ALPHA01 [Layer] [alpha0] [alpha1] > /proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[Layer] fb hierarchy ，GUI:ui layer；CURSOR:cursor layer. [Alpha0] alpha0 value [Alpha1] alpha1 value
Example	echo ALPHA01 GUI 0xff 0 > /proc/mi_modules/mi_fb/mi_fb0 Set the pixel alpha0 as 0xff and alpha1 as 0 on ui layer of ARGB1555 format.

Function	Set the global alpha value on ui layer or cursor layer respectively.
Command	echo GLOBAL_ALPHA [Layer] [GlobalAlpha] > /proc/mi_modules/mi_fb/mi_fbx
Parameter Description	[Layer] fb hierarchy ，GUI:ui layer；CURSOR:cursor layer. [GlobalAlpha] gloabl alpha value
Example	echo GLOBAL_ALPHA GUI 0xff > /proc/mi_modules/mi_fb/mi_fb0 Set the global alpha as 0xff on ui layer

6. MODPARAM.json Description¶

6.1. The json file content¶

"E_MI_MODULE_ID_FB" :
{
    "b_keep_bootlogo": false
}

The modparam.json is under /config, when sys is initialized, the json file will be loaded.

6.2. FB common paramaters and paramater description¶

Parameters	Default value	Supported chips	Customer configuration	Function
b_keep_bootlogo	false	Pcupid	Y	Control the function of bootlogo seamless transition from uboot to MI_FB

6.3. Example of parameter usage¶

6.3.1. b_keep_bootlogo¶

This parameter is used to control the function of bootlogo seamless transition from uboot to MI_FB. Only enable it when using MI_RGN to display the bootlogo. When the function is enabled, the first time of the user calls "PanDisplay" after opening the fb device will switch the screen from bootlogo to framebuffer.

"b_keep_bootlogo": false, means to disable the function of bootlogo seamless transition from uboot to MI_FB.
"b_keep_bootlogo": true, means to enable the function of bootlogo seamless transition from uboot to MI_FB.

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_VSCREENINFO	ioctl cmd	Input
var	Variable information structure pointer	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOPUT_VSCREENINFO	ioctl cmd	Input
var	Variable information structure pointer	Input

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_FSCREENINFO	ioctl cmd	Input
fix	Fixed information structure pointer	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOPAN_DISPLAY	ioctl cmd	Input
var	Variable information structure pointer	Input

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGETCMAP	ioctl cmd	Input
zero	be sure to pass argument value 0 or it will not work.	Input

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOPUTCMAP	ioctl cmd	Input
cmap	Describe the color table info	Input

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_GLOBAL_ALPHA	ioctl cmd	Input
pstAlpha	Pointer to MI_FB_GlobalAlpha_t structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_GLOBAL_ALPHA	ioctl cmd	Input
pstAlpha	Pointer to MI_FB_GlobalAlpha_t structure	Input

Parameter Name	Description	Input/Output
Fd	Framebuffer device file descriptor	Input
FBIOGET_COLORKEY	ioctl cmd	Input
pstColorKey	Pointer to MI_FB_ColorKey_t structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_COLORKEY	ioctl cmd	Input
pstColorKey	Pointer to MI_FB_ColorKey_t structure	Input

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_DISPLAYLAYER_ATTRIBUTES	ioctl cmd	Input
pstLayerInfo	Pointer to graphic layer structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_CURSOR_ATTRIBUTE	ioctl cmd	Input
pstCursorAttr	Pointer to MI_FB_CursorAttr_t structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_CURSOR_ATTRIBUTE	ioctl cmd	Input
pstCursorAttr	Pointer to MI_FB_CursorAttr_t structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOGET_COMPRESSIONINFO	ioctl cmd	Input
pstCompression	MI_FB_Compression_t structure	Output

Parameter Name	Description	Input/Output
fd	Framebuffer device file descriptor	Input
FBIOSET_COMPRESSIONINFO	ioctl cmd	Input
pstCompression	MI_FB_Compression_t structure	Input

Parameter Name	Description	Input/Output
u32FbId	FB device number	Input
u32size	buff size	Input
pVirAddr	Return the mapped virtual address	Output

Member name	Description
E_MI_FB_OUTPUT_RGB	RGB ColorSpace
E_MI_FB_OUTPUT_YUV	YUV ColorSpace

Member	Description
bKeyEnable	Colorkey enable. TRUE: Enable FALSE: Not enable
u8Red	Colorkey R component value
u8Green	Colorkey G component value
u8Blue	Colorkey B component value

Member	Description
u32Width	Icon width
u32Height	Icon height
u32Pitch	pitch
eColorFmt	Icon data pixel format
pData	Icon data