Load .bin from flash memory

jaeho · July 12, 2021, 7:49am

Hi, everyone.
I’m developing based on zephyr RTOS using STM32F429i board.

I was working on LVGL 7.6.1 and tried to load .bin (convert png to bin) from flash memory.
also I used littlefs filesystem.

it was simple code.

lv_obj_t* img = lv_img_create(lv_scr_act(), NULL );
lv_img_set_src( img, “S:/lfs/img/left.bin” );
lv_obj_align( img, NULL, LV_ALIGN_CENTER, 0, 0);

and also I pushed left.bin to “/lfs/img” like below

however, the image isn’t shown. so I checked in detail.

when I try to open the image file, I found return value is EBUSY.
so I check the source code. and finally I found the problem code.

github.com

zephyrproject-rtos/zephyr/blob/main/subsys/fs/fs.c#L146

    
      
          
          
	/* COpy flags to zfp for use with other fs_ API calls */
          	zfp->flags = flags;
          
          
	if ((file_name == NULL) ||
          			(strlen(file_name) <= 1) || (file_name[0] != '/')) {
          		LOG_ERR("invalid file name!!");
          		return -EINVAL;
          	}
          
          
	if (zfp->mp != NULL) {
          		return -EBUSY;
          	}
          
          
	rc = fs_get_mnt_point(&mp, file_name, NULL);
          	if (rc < 0) {
          		LOG_ERR("mount point not found!!");
          		return rc;
          	}
          
          
	if (((mp->flags & FS_MOUNT_FLAG_READ_ONLY) != 0) &&

I’m not sure but call flow is like below;

lv_fs_open() : lv_img_decoder_built_in_info
fs_open() : lvgl_fs_open()
return EBUSY in fs_open()

checked in detail in lv_fs_open()
when allocating in file_p->file_d variable, I think memory initialize is needed. so I add _lv_memset() function. sizeof(struct fs_file_t) is 12. after that, image is shown and there is no EBUSY error.
I think there was garbage value in file_p->file_d. so zfp->mp is not NULL ( return EBUSY value )

is there anything I missed?
please let me know.

Thanks