这个工程主要是简单的显示SD卡的文件目录。
+ T$ b6 ]$ Q2 M2 t5 b" G9 CThis project implements a simple file explorer that displays the directory structure on the SD card.The included CircleOs binary include a SDIO driver and a Fat12/16/32 implementation based on DosFS. This a demo project to show usage of the SD card.
  _% E- t# e$ V+ z$ Q! VThis project is aimed to be a demo project about how to use the CircleOS filesystem. It can display PRM (converted BMP, JPG, etc) images with a sample viewer.
# I( U& `# U4 l7 wIncluded in this project an application to convert BMP, JPG, etc files to PRM with the functionality to scale the image to a desired resolution.
 Current layout of PRM image file:
$ \/ E8 X7 O. ~# R4 w 8byte header:
4 p6 f8 S, I2 U* u* |5 O* E- R- byte 0: height
  q% I# N' p& b' M5 B* c2 G! `; Z- byte 1: width
- 6 bytes for future use
8 ]; t, `7 f8 L  a/ O, z  E7 g- pixel data (2 bytes per pixel)
 FS interface functions:
0 G6 {. v% h+ `9 v* C' j1 Ku32 FS_Mount(enum STORAGE_device device);
1 B- H' M2 b& Iu32 FS_Unmount(enum STORAGE_device device);
7 d' W9 U3 p9 e& C3 z1 P2 P8 q# lu32 FS_OpenFile(PVOLINFO volinfo, u8 *path, u8 mode, PFILEINFO fileinfo);
u32 FS_ReadFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
( G6 {" c: \/ s& [/ du32 FS_WriteFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
u32 FS_Close(PFILEINFO fileinfo);
' J0 t7 \, [3 L7 k, J7 e, `3 Lvoid FS_Seek(PFILEINFO fileinfo, u32 offset);
u32 FS_Delete(PVOLINFO volinfo, u8 *path);
" e9 `: \2 w5 {3 A6 Z) y! K/ h5 Nu32 FS_GetNextEntry(PVOLINFO volinfo, PDIRINFO dirinfo, PDIRENT dirent);
u32 FS_OpenDirectory(PVOLINFO volinfo,u8 *dirname, PDIRINFO dirinfo);
9 z1 j  u; O5 Y7 Uu32 FS_GetVolumeInfo(u8 unit,  u32 startsector, PVOLINFO volinfo);
 
' E6 X! v  A. v! F 
This is a snapshot of my current work in progress with partially integrated jpg decompressor
7 p* T, S" N# x0 ^: y; C/ e