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#include <string.h>
#include <FreeRTOS.h>
#include <semphr.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "fio.h"
#include "filesystem.h"
#include "romfs.h"
#include "osdebug.h"
#include "hash-djb2.h"
struct romfs_fds_t {
const uint8_t * file;
uint32_t cursor;
};
static struct romfs_fds_t romfs_fds[MAX_FDS];
static uint32_t get_unaligned(const uint32_t * _d) {
const uint8_t * d = (const uint8_t *) _d;
return ((uint32_t) d[0]) | ((uint32_t) (d[1] << 8)) | ((uint32_t) (d[2] << 16)) | ((uint32_t) (d[3] << 24));
}
static ssize_t romfs_read(void * opaque, void * buf, size_t count) {
struct romfs_fds_t * f = (struct romfs_fds_t *) opaque;
const uint8_t * size_p = f->file - 4;
uint32_t size = get_unaligned((uint32_t *) size_p);
if ((f->cursor + count) > size)
count = size - f->cursor;
memcpy(buf, f->file + f->cursor, count);
f->cursor += count;
return count;
}
static off_t romfs_seek(void * opaque, off_t offset, int whence) {
struct romfs_fds_t * f = (struct romfs_fds_t *) opaque;
const uint8_t * size_p = f->file - 4;
uint32_t size = get_unaligned((uint32_t *) size_p);
uint32_t origin;
switch (whence) {
case SEEK_SET:
origin = 0;
break;
case SEEK_CUR:
origin = f->cursor;
break;
case SEEK_END:
origin = size;
break;
default:
return -1;
}
offset = origin + offset;
if (offset < 0)
return -1;
if (offset > size)
offset = size;
f->cursor = offset;
return offset;
}
static int romfs_open(void * opaque, const char * path, int flags, int mode) {
uint32_t h = hash_djb2((const uint8_t *) path, -1);
const uint8_t * romfs = (const uint8_t *) opaque;
const uint32_t * meta;
int r = -1;
for (meta = (uint32_t *) romfs; get_unaligned(meta) && get_unaligned(meta + 1); romfs = romfs + meta[1], meta = (uint32_t *) romfs) {
if (meta[0] == h) {
r = fio_open(romfs_read, NULL, romfs_seek, NULL, NULL);
if (r > 0) {
romfs_fds[r].file = romfs + 8;
romfs_fds[r].cursor = 0;
fio_set_opaque(r, romfs_fds + r);
}
break;
}
}
return r;
}
void register_romfs(const char * mountpoint, const uint8_t * romfs) {
DBGOUT("Registering romfs `%s' @ %p\r\n", mountpoint, romfs);
register_fs(mountpoint, romfs_open, (void *) romfs);
}
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