产品设计出来之后啊，大家使用的时候觉得反过来使用更加便捷。但是屏幕显示是反的。那怎么办那？？？？？

(资料图片)

修改硬件费时费工，那能否软件实现那？？？？？

如果纯软件使用那就太费系统资源了。于是就想到了使用全志R528自带的G2D功能（硬件加速功能）。

使用它进行旋转，后又发现uboot阶段系统没有G2D导致开机logo不能自动旋转，内核启动后G2D启动logo又旋转了。

（好烦啊！！！！！！！！！！！！）

于是就需要把uboot阶段手动把图片数据旋转过来。在G2D启动前把uboot 传递给内核的logo图片数据也旋转过来。

下面具体步骤：

一、开启G2D功能。

1、由于此前公版默认在modules.mk屏蔽了屏旋转相关配置, 如果你的版本是禁用旋转的, 需要把相关配置去掉.device/config/chips/r528/configs/evb1/linux-5.4/config-5.4

2759:# CONFIG_SUNXI_DISP2_FB_DISABLE_ROTATE is not set以下3个相关选项

CONFIG_DISP2_SUNXI=m \#CONFIG_SUNXI_DISP2_FB_DISABLE_ROTATE=y \#CONFIG_SUNXI_DISP2_FB_ROTATION_SUPPORT=n \#CONFIG_SUNXI_DISP2_FB_HW_ROTATION_SUPPORT=n \修改为：

CONFIG_DISP2_SUNXI=m \#CONFIG_SUNXI_DISP2_FB_DISABLE_ROTATE=n \#CONFIG_SUNXI_DISP2_FB_ROTATION_SUPPORT=n \#CONFIG_SUNXI_DISP2_FB_HW_ROTATION_SUPPORT=y \

2、硬件旋转需要确保G2D驱动已经使能

make kernel_menuconfigDevice Drivers ---><*> SUNXI G2D Driver[*] sunxi g2d mixer module[*] sunxi g2d rotate module[] sunxi sync fence implement for rotate jobs synchronous

3.打开显示驱动旋转支持

make kernel_menuconfigDevice Drivers --->Graphics support --->Frame buffer Devices --->Video support for sunxi --->DISP2 Framebuffer rotation support (Disable rotation) --->( ) Disable rotation( ) Software rotation support (不要选这个,方案未支持)(X) Hardware(G2D) rotation support (选择G2D旋转)

4.dts配置

board.dts 和 uboot-board.dts同步修改.

&disp{.....disp_rotation_used = <1>;/* 使能旋转功能 */degree0 = <2>; /* X:screen index; 0:0 degree; 1:90 degree; 3:270 degree */fb0_width = <800>;/*fb 的长宽交换*/fb0_height = <480>;.....};

5.旋转后framebuffer编程是需要注意,旋转后的buffer不会直接显示到屏幕上, 需要在应用刷屏的地方调用FBIOPAN_DISPLAY接口.同步旋转后的buffer到LCD上.

以修改公版旋转的GUI刷屏示例:

路径:package/gui/littlevgl-6/lv_drivers/display/fbdev.cvoid fbdev_flush(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_p){....    lv_disp_flush_ready(drv);    ioctl(fbfd, FBIOPAN_DISPLAY, &vinfo); /*函数最后,在刷屏函数后面,调用 FBIOPAN_DISPLAY 接口*/}

我们系统时自己的UI系统。是在重绘回调函数中，增加FBIOPAN_DISPLAY

main(){  int fp=0;struct fb_var_screeninfo vinfo;struct fb_fix_screeninfo finfo;fp = open("/dev/fb0", O_RDWR);if(fp < 0) {printf("Error : Can not open framebuffer device/n");exit(1);}if(ioctl(fp, FBIOGET_VSCREENINFO, &vinfo)){printf("Error reading variable information/n");exit(3);}vinfo.xoffset = 0;vinfo.yoffset = 0;  } void sys_paint(void) // 每次重绘调用一次{　　ioctl(fbfd, FBIOPAN_DISPLAY, &vinfo); /*函数最后,在刷屏函数后面,调用 FBIOPAN_DISPLAY 接口*/}

二、uboot阶段手动修改旋转图片数据

追踪uboot logo执行过程

static int run_main_loop(void)  {....    #ifdef CONFIG_ARCH_SUNXI        initr_sunxi_plat,    #endif....}initr_sunxi_plat{....              #ifdef CONFIG_BOOT_GUI                void board_bootlogo_display(void);                board_bootlogo_display();        #else....}void board_bootlogo_display(void) {....#if defined(CONFIG_CMD_SUNXI_BMP)    sunxi_bmp_display("bootlogo.bmp"); //指定bootlogo的名字。通过修改这个地方可以修改指定logo的名称    #elif defined(CONFIG_CMD_SUNXI_JPEG)    sunxi_jpeg_display("bootlogo.jpg");#endif    ....}int sunxi_bmp_display(char *name){    int ret = -1;    char *argv[6];    char bmp_head[32];273    char bmp_name[32];    char part_info[16] = {0};    char size[32] = {0};    int partno = -1;    unsigned long file_size = 0;    char *bmp_head_addr;    struct bmp_image *bmp;    bmp = memalign(CONFIG_SYS_CACHELINE_SIZE,  ALIGN(sizeof(struct bmp_header), CONFIG_SYS_CACHELINE_SIZE));    if (bmp) {        sprintf(bmp_head, "%lx", (ulong)bmp);    } else {        pr_error("sunxi bmp: alloc buffer for %s fail\n", name);        goto out;    }    partno = sunxi_partition_get_partno_byname("bootloader"); /*android*/    if (partno < 0) {        partno = sunxi_partition_get_partno_byname(            "boot-resource"); /*linux*/        if (partno < 0) {            pr_error("Get bootloader and boot-resource partition number fail!\n");            goto free1;        }    }    snprintf(part_info, 16, "0:%x", partno);    strncpy(bmp_name, name, sizeof(bmp_name));    snprintf(size, 16, "%lx", (ulong)sizeof(struct bmp_header));    argv[0] = "fatload";    argv[1] = "sunxi_flash";    argv[2] = part_info;    argv[3] = bmp_head;    argv[4] = bmp_name;    argv[5] = size;    if (do_fat_fsload(0, 0, 6, argv)) {        pr_error("sunxi bmp info error : unable to open logo file %s\n",               argv[4]);        goto free1;    }    if ((bmp->header.signature[0] != "B") ||        (bmp->header.signature[1] != "M")) {        pr_error("this is not a bmp picture\n");        goto free1;    }    file_size = bmp->header.file_size;    bmp_head_addr = memalign(CONFIG_SYS_CACHELINE_SIZE,  ALIGN(file_size, CONFIG_SYS_CACHELINE_SIZE));    if (bmp_head_addr) {        sprintf(bmp_head, "%lx", (ulong)bmp_head_addr);    } else {        pr_error("sunxi bmp: alloc buffer for %s fail\n", name);        goto free1;    }    snprintf(size, 16, "%lx", (ulong)file_size);    tick_printf("bmp_name=%s size %ld\n", bmp_name, file_size);    if (do_fat_fsload(0, 0, 6, argv)) {        pr_error("sunxi bmp info error : unable to open logo file %s\n",               argv[4]);        goto free2;    }//在调用show_bmp_on_fb 之前将bmp_head_addr中的图片数据进行旋转

// 调用旋转函数 　　rotateBMP180(bmp_head_addr);

ret = show_bmp_on_fb(bmp_head_addr, FB_ID_0);    if (ret != 0)        pr_error("show bmp on fb failed !%d\n", ret);free2:    free(bmp_head_addr);free1:    free(bmp);out:    return ret;}        

旋转函数：

主要发现uboot阶段malloc不能申请太大的内存空间，所以代码中申请的行的大小。

#pragma pack(push, 1)typedef struct {    uint16_t type;    uint32_t size;    uint16_t reserved1;    uint16_t reserved2;    uint32_t offset;} BMPFileHeader;#pragma pack(pop)// 定义BMP图像信息头结构体#pragma pack(push, 1)typedef struct {    uint32_t header_size;    int32_t width;    int32_t height;    uint16_t planes;    uint16_t bit_count;    uint32_t compression;    uint32_t image_size;    int32_t x_pixels_per_meter;    int32_t y_pixels_per_meter;    uint32_t colors_used;    uint32_t colors_important;} BMPInfoHeader;#pragma pack(pop)// 旋转BMP图像180度void rotateBMP180(char * bmp_head_add) {    // 读取文件头    BMPFileHeader* file_header = (BMPFileHeader*)bmp_head_add;    // 读取图像信息头    BMPInfoHeader* info_header = (BMPInfoHeader*)(bmp_head_add + sizeof(BMPFileHeader));    // 获取图像宽度、高度和每行像素所占字节数    int32_t width = info_header->width;    int32_t height = info_header->height;    uint32_t row_size = (info_header->bit_count * width + 31) / 32 * 4;    // 创建临时缓冲区存储旋转后的图像数据    uint8_t* temp_data = (uint8_t*)malloc(row_size);    if (temp_data == NULL) {        printf("Failed to allocate memory for temporary data.\n");        return;    }    // 旋转图像    for (int32_t row = 0; row < height / 2; ++row) {        for (int32_t col = 0; col < width; ++col) {            // 计算当前像素位置和对应的对称像素位置            int32_t original_index = row * row_size + col * 3;            int32_t symmetric_index = (height - 1 - row) * row_size + (width - 1 - col) * 3;            // 交换像素颜色值            uint8_t temp_red = bmp_head_add[file_header->offset + original_index];            uint8_t temp_green = bmp_head_add[file_header->offset + original_index + 1];            uint8_t temp_blue = bmp_head_add[file_header->offset + original_index + 2];            bmp_head_add[file_header->offset + original_index] = bmp_head_add[file_header->offset + symmetric_index];            bmp_head_add[file_header->offset + original_index + 1] = bmp_head_add[file_header->offset + symmetric_index + 1];            bmp_head_add[file_header->offset + original_index + 2] = bmp_head_add[file_header->offset + symmetric_index + 2];            bmp_head_add[file_header->offset + symmetric_index] = temp_red;            bmp_head_add[file_header->offset + symmetric_index + 1] = temp_green;            bmp_head_add[file_header->offset + symmetric_index + 2] = temp_blue;        }    }    // 释放临时缓冲区内存    free(temp_data);}

三、kernel阶段手动修改旋转logo图片数据

追踪内核执行过程

disp_module_init{........    platform_driver_unregister(&disp_driver);#ifndef CONFIG_OF    platform_device_unregister(&disp_device);#endif........}static int disp_probe(struct platform_device *pdev){........        bsp_disp_init(para);........}static s32 disp_init(struct platform_device *pdev)    {........    lcd_init();    bsp_disp_open();    fb_init(pdev);........}s32 fb_init(struct platform_device *pdev){........    ret = display_fb_request(i, &fb_para);........}static s32 display_fb_request(u32 fb_id, struct disp_fb_create_info *fb_para){........    Fb_map_kernel_logo(sel, info);........}static int Fb_map_kernel_logo(u32 sel, struct fb_info *info){........    paddr = bootlogo_addr;    if (paddr == 0) {        __inf("Fb_map_kernel_logo failed!");        return Fb_copy_boot_fb(sel, info);    }........}static int Fb_copy_boot_fb(u32 sel, struct fb_info *info){    enum {        BOOT_FB_ADDR = 0,        BOOT_FB_WIDTH,        BOOT_FB_HEIGHT,        BOOT_FB_BPP,        BOOT_FB_STRIDE,        BOOT_FB_CROP_L,        BOOT_FB_CROP_T,        BOOT_FB_CROP_R,        BOOT_FB_CROP_B,    };    char *boot_fb_str = NULL;    char *src_phy_addr = NULL;    char *src_addr = NULL;    char *src_addr_b = NULL;    char *src_addr_e = NULL;    int src_width = 0;    int src_height = 0;    int fb_height = 0;    int src_bpp = 0;    int src_stride = 0;    int src_cp_btyes = 0;    int src_crop_l = 0;    int src_crop_t = 0;    int src_crop_r = 0;    int src_crop_b = 0;    char *dst_addr = NULL;    int dst_width = 0;    int dst_height = 0;    int dst_bpp = 0;    int dst_stride = 0;    int ret;    unsigned long map_offset;    if (info == NULL) {        __wrn("%s,%d: null pointer\n", __func__, __LINE__);        return -1;    }    boot_fb_str = (char *)disp_boot_para_parse_str("boot_fb0");    if (boot_fb_str != NULL) {        int i = 0;        char boot_fb[128] = { 0 };        int len = strlen(boot_fb_str);        if (sizeof(boot_fb) - 1 < len) {            __wrn("need bigger array size[%d] for boot_fb\n", len);            return -1;        }        memcpy((void *)boot_fb, (void *)boot_fb_str, len);        boot_fb[len] = "\0";        boot_fb_str = boot_fb;        for (i = 0;; ++i) {            char *p = strstr(boot_fb_str, ",");            if (p != NULL)                *p = "\0";            if (i == BOOT_FB_ADDR) {                ret = kstrtoul(boot_fb_str, 16,                    (unsigned long *)&src_phy_addr);                if (ret)                    pr_warn("parse src_phy_addr fail!\n");            } else if (i == BOOT_FB_WIDTH) {                ret = kstrtou32(boot_fb_str, 16, &src_width);                if (ret)                    pr_warn("parse src_width fail!\n");            } else if (i == BOOT_FB_HEIGHT) {                ret = kstrtou32(boot_fb_str, 16, &src_height);                fb_height = src_height;                if (ret)                    pr_warn("parse src_height fail!\n");            } else if (i == BOOT_FB_BPP) {                ret = kstrtou32(boot_fb_str, 16, &src_bpp);                if (ret)                    pr_warn("parse src_bpp fail!\n");            } else if (i == BOOT_FB_STRIDE) {                ret = kstrtou32(boot_fb_str, 16, &src_stride);                if (ret)                    pr_warn("parse src_stride fail!\n");            } else if (i == BOOT_FB_CROP_L) {                ret = kstrtou32(boot_fb_str, 16, &src_crop_l);                if (ret)                    pr_warn("parse src_crop_l fail!\n");            } else if (i == BOOT_FB_CROP_T) {                ret = kstrtou32(boot_fb_str, 16, &src_crop_t);                if (ret)                    pr_warn("parse src_crop_t fail!\n");            } else if (i == BOOT_FB_CROP_R) {                ret = kstrtou32(boot_fb_str, 16, &src_crop_r);                if (ret)                    pr_warn("parse src_crop_r fail!\n");            } else if (i == BOOT_FB_CROP_B) {                ret = kstrtou32(boot_fb_str, 16, &src_crop_b);                if (ret)                    pr_warn("parse src_crop_b fail!\n");            } else {                break;            }            if (p == NULL)                break;            boot_fb_str = p + 1;        }    } else {        __wrn("no boot_fb0\n");        return -1;    }    dst_addr = (char *)(info->screen_base);    dst_width = info->var.xres;    dst_height = info->var.yres;    dst_bpp = info->var.bits_per_pixel;    dst_stride = info->fix.line_length;    if ((src_phy_addr == NULL)        || (src_width <= 0)        || (src_height <= 0)        || (src_stride <= 0)        || (src_bpp <= 0)        || (dst_addr == NULL)        || (dst_width <= 0)        || (dst_height <= 0)        || (dst_stride <= 0)        || (dst_bpp <= 0)        || (src_bpp != dst_bpp)) {        __wrn            ("wrong para: src[phy_addr=%p,w=%d,h=%d,bpp=%d,stride=%d], dst[addr=%p,w=%d,h=%d,bpp=%d,stride=%d]\n",             src_phy_addr,             src_width, src_height, src_bpp, src_stride, dst_addr,             dst_width, dst_height, dst_bpp, dst_stride);        return -1;    }    map_offset = (unsigned long)src_phy_addr + PAGE_SIZE        - PAGE_ALIGN((unsigned long)src_phy_addr + 1);    src_addr = (char *)Fb_map_kernel_cache((unsigned long)src_phy_addr -                           map_offset,                           src_stride * src_height +                           map_offset);    if (src_addr == NULL) {        __wrn("Fb_map_kernel_cache for src_addr failed\n");        return -1;    }    src_addr_b = src_addr + map_offset;    if ((src_crop_b > src_crop_t) &&        (src_height > src_crop_b - src_crop_t) &&        (src_crop_t >= 0) &&        (src_height >= src_crop_b)) {        src_height = src_crop_b - src_crop_t;        src_addr_b += (src_stride * src_crop_t);    }    if ((src_crop_r > src_crop_l)        && (src_width > src_crop_r - src_crop_l)        && (src_crop_l >= 0)        && (src_width >= src_crop_r)) {        src_width = src_crop_r - src_crop_l;        src_addr_b += (src_crop_l * src_bpp >> 3);    }    // 旋转图片数据   // rotateImage180(src_addr_b, src_width, src_height, src_bpp, src_stride);            if (src_height < dst_height) {        int dst_crop_t = (dst_height - src_height) >> 1;        dst_addr += (dst_stride * dst_crop_t);    } else if (src_height > dst_height) {        __wrn("src_height(%d) > dst_height(%d),please cut the height\n",              src_height,              dst_height);        Fb_unmap_kernel(src_addr);        return -1;    }    if (src_width < dst_width) {        int dst_crop_l = (dst_width - src_width) >> 1;        dst_addr += (dst_crop_l * dst_bpp >> 3);    } else if (src_width > dst_width) {        __wrn("src_width(%d) > dst_width(%d),please cut the width!\n",              src_width,              dst_width);        Fb_unmap_kernel(src_addr);        return -1;    }    src_cp_btyes = src_width * src_bpp >> 3;    src_addr_e = src_addr_b + src_stride * src_height;    for (; src_addr_b != src_addr_e; src_addr_b += src_stride) {        memcpy((void *)dst_addr, (void *)src_addr_b, src_cp_btyes);        dst_addr += dst_stride;    }       //再此地方旋转修改    dst_addr = (char *)(info->screen_base);    rotateImage180(dst_addr, dst_width, dst_height, dst_bpp, dst_stride);    Fb_unmap_kernel(src_addr);    memblock_free((unsigned long)src_phy_addr, src_stride * fb_height);    free_reserved_area(__va(src_phy_addr), __va(src_phy_addr + PAGE_ALIGN(src_stride * fb_height)), 0x00, "logo buffer");    return 0;}    

旋转180函数：

放在 tina-r528\lichee\linux-5.4\drivers\video\fbdev\sunxi\disp2\disp\dev_fb.c

注意此处由于申请的内存空间比较大，所以用的是vmalloc

void rotateImage180(char* src_addr, int width, int height, int bpp, int stride) {                    // 计算每行像素数据的字节数    int row_bytes = width * (bpp / 8);        char * src_addr_e = src_addr + stride* height; //最后的地址位置    // 创建临时缓冲区用于保存旋转后的图像数据    char* temp_data = vmalloc(row_bytes * height);        int y=0,x=0;    // 复制旋转后的图像数据到临时缓冲区    for (y = 0; y < height; y++) {        char* src_row_start = src_addr + (y * stride);        char* dest_row_start = temp_data + ((height - 1 - y) * row_bytes);                // 复制像素数据并进行左右翻转                        for ( x = 0; x < width; x++) {                                char* src_pixel = src_row_start + (x * (bpp / 8));                                char* dest_pixel = dest_row_start + ((width - 1 - x) * (bpp / 8));                                // 复制像素值                                memcpy(dest_pixel, src_pixel, (bpp / 8));                        }    }       //printk("----%s--%d\n",__func__,__LINE__);        // 将旋转后的图像数据写回原始内存地址        for (; src_addr != src_addr_e; src_addr += stride) {  //循环复制每一行                memcpy((void *)src_addr, (void *)temp_data, row_bytes);                temp_data += row_bytes;  //地址是增加地址宽度        }        //printk("----%s--%d\n",__func__,__LINE__);    // 释放临时缓冲区    vfree(temp_data);}

参考资料：

(67条消息) uboot修改启动logo-sunxi_u-boot启动时改横屏_Chasing_Chasing的博客-CSDN博客

【FAQ】全志F133（D1s）芯片 如何在Tina下进行显示旋转？ | 全志在线开发者论坛 (aw-ol.com)