Alexander Myltsev babf3897f4 Add fs.c.
2022-12-13 00:50:28 +03:00

40 lines
1.1 KiB
C

#include "fs.h"
#include "../string.h"
#include "../drivers/ata.h"
enum {
fs_start = 1, // sector where the FS starts
};
int stat(const char* name, struct stat *buf) {
struct dir dir;
read_sectors_ATA_PIO(&dir, fs_start, 1);
for (int i = 0; i < ents_in_dir; ++i) {
struct dirent *e = &dir.entries[i];
if (!strncmp(e->name, name, sizeof(e->name))) {
buf->size = e->size_bytes;
buf->reserved[0] = e->offset_sectors;
return 0;
}
}
return -1;
}
/* Find file by name and read it into buffer with size bufsize.
* At most (bufsize & -512) bytes will be read.
* Return number of bytes read or -1 on failure. */
int read_file(const char* name, void* buf, uint32_t bufsize) {
struct stat statbuf;
if (stat(name, &statbuf) != 0) {
return -1;
}
uint32_t sector = fs_start + statbuf.reserved[0];
while (bufsize >= sector_size) {
read_sectors_ATA_PIO(buf, sector, 1);
sector++;
bufsize -= sector_size;
buf += sector_size;
}
return 0;
}