这个工程主要是简单的显示SD卡的文件目录。
This 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.
" c6 h- w3 X. zThis 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.
Included in this project an application to convert BMP, JPG, etc files to PRM with the functionality to scale the image to a desired resolution.
8 n% z/ s8 R( e6 B  D2 r( I Current layout of PRM image file:
$ g3 }& R* F/ P8 k1 C0 d* p 8byte header:
0 Q! W  t  T- W5 _: i- byte 0: height
- byte 1: width
: C5 x) W' o& V: a) z; u3 u/ {7 _- 6 bytes for future use
- pixel data (2 bytes per pixel)
0 V( H2 W9 A4 H3 l FS interface functions:
4 y0 }# _* a* H' `" @u32 FS_Mount(enum STORAGE_device device);
1 K( c1 m+ t% m9 z* L& P. X9 Ru32 FS_Unmount(enum STORAGE_device device);
5 a" g& y5 C% b5 M9 Du32 FS_OpenFile(PVOLINFO volinfo, u8 *path, u8 mode, PFILEINFO fileinfo);
u32 FS_ReadFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
9 Y1 G; p# J9 U8 }( Z1 M7 E& b) M% [u32 FS_WriteFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
u32 FS_Close(PFILEINFO fileinfo);
% L) B& }. c: o) ~5 D2 Jvoid FS_Seek(PFILEINFO fileinfo, u32 offset);
# g. o0 k; D/ o5 e" Fu32 FS_Delete(PVOLINFO volinfo, u8 *path);
u32 FS_GetNextEntry(PVOLINFO volinfo, PDIRINFO dirinfo, PDIRENT dirent);
. O" K% y0 q" S' Xu32 FS_OpenDirectory(PVOLINFO volinfo,u8 *dirname, PDIRINFO dirinfo);
u32 FS_GetVolumeInfo(u8 unit,  u32 startsector, PVOLINFO volinfo);
; h. t6 ?6 @+ t' y 
 
# A8 b7 X0 Q6 n8 s- Y) G" n* MThis is a snapshot of my current work in progress with partially integrated jpg decompressor

$ t2 R* M* \7 D0 Z! R