这个工程主要是简单的显示SD卡的文件目录。
" c6 w0 N  \4 K5 Z: t0 q% EThis 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.
This 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.
: x6 `8 t' @2 y2 J( ZIncluded in this project an application to convert BMP, JPG, etc files to PRM with the functionality to scale the image to a desired resolution.
/ _$ q/ @* H- U& i Current layout of PRM image file:
 8byte header:
- byte 0: height
# |. @* ~( K( g! k" o- byte 1: width
- 6 bytes for future use
6 b% D5 z$ w( W% ~! [! _- pixel data (2 bytes per pixel)
; V7 E" T, E/ [' i, V% P FS interface functions:
u32 FS_Mount(enum STORAGE_device device);
+ L! `& {# O) b0 bu32 FS_Unmount(enum STORAGE_device device);
u32 FS_OpenFile(PVOLINFO volinfo, u8 *path, u8 mode, PFILEINFO fileinfo);
, U2 R4 L  M( c+ m* Iu32 FS_ReadFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
& B$ `& Q" A. @9 \7 C# B5 [7 Iu32 FS_WriteFile(PFILEINFO fileinfo,  u8 *buffer, u32 *successcount, u32 len);
; n: [; t  |) u9 t1 @( Ku32 FS_Close(PFILEINFO fileinfo);
void FS_Seek(PFILEINFO fileinfo, u32 offset);
) ]: a8 a, L! l  b4 w5 z& i2 R; N0 Du32 FS_Delete(PVOLINFO volinfo, u8 *path);
u32 FS_GetNextEntry(PVOLINFO volinfo, PDIRINFO dirinfo, PDIRENT dirent);
, G' H, T5 J* bu32 FS_OpenDirectory(PVOLINFO volinfo,u8 *dirname, PDIRINFO dirinfo);
" N( K+ U6 q9 B5 K& u, Ou32 FS_GetVolumeInfo(u8 unit,  u32 startsector, PVOLINFO volinfo);
 
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/ A8 v3 N/ J3 F# \3 J! YThis is a snapshot of my current work in progress with partially integrated jpg decompressor

+ b. e$ y) p# }( I+ J8 r4 _* ~* m