/*
* trx.c
*
- * Copyright (C) 2005 Mike Baker
+ * Copyright (C) 2005 Mike Baker
* Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or
#include <sys/mman.h>
#include <sys/stat.h>
#include <string.h>
+#include <errno.h>
#include <sys/ioctl.h>
#include "mtd-api.h"
#include "mtd.h"
+#include "crc32.h"
#define TRX_MAGIC 0x30524448 /* "HDR0" */
struct trx_header {
- unsigned magic; /* "HDR0" */
- unsigned len; /* Length of file including header */
- unsigned crc32; /* 32-bit CRC from flag_version to end of file */
- unsigned flag_version; /* 0:15 flags, 16:31 version */
- unsigned offsets[3]; /* Offsets of partitions from start of header */
+ uint32_t magic; /* "HDR0" */
+ uint32_t len; /* Length of file including header */
+ uint32_t crc32; /* 32-bit CRC from flag_version to end of file */
+ uint32_t flag_version; /* 0:15 flags, 16:31 version */
+ uint32_t offsets[3]; /* Offsets of partitions from start of header */
};
-static unsigned long *crc32 = NULL;
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define STORE32_LE(X) ((((X) & 0x000000FF) << 24) | (((X) & 0x0000FF00) << 8) | (((X) & 0x00FF0000) >> 8) | (((X) & 0xFF000000) >> 24))
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+#define STORE32_LE(X) (X)
+#else
+#error unknown endianness!
+#endif
-static void init_crc32()
-{
- unsigned long crc;
- unsigned long poly = 0xEDB88320L;
- int n, bit;
-
- if (crc32)
- return;
-
- crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long));
- if (!crc32) {
- perror("malloc");
- exit(1);
- }
-
- for (n = 0; n < 256; n++) {
- crc = (unsigned long) n;
- for (bit = 0; bit < 8; bit++)
- crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
- crc32[n] = crc;
- }
-}
-
-static unsigned int crc32buf(char *buf, size_t len)
-{
- unsigned int crc = 0xFFFFFFFF;
- for (; len; len--, buf++)
- crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
- return crc;
-}
+ssize_t pread(int fd, void *buf, size_t count, off_t offset);
+ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
int
trx_fixup(int fd, const char *name)
goto err;
}
- init_crc32();
scan = ptr + offsetof(struct trx_header, flag_version);
trx->crc32 = crc32buf(scan, trx->len - (scan - ptr));
msync(ptr, sizeof(struct trx_header), MS_SYNC|MS_INVALIDATE);
return 1;
}
+int
+mtd_fixtrx(const char *mtd, size_t offset)
+{
+ int fd;
+ struct trx_header *trx;
+ char *buf;
+ ssize_t res;
+ size_t block_offset;
+
+ if (quiet < 2)
+ fprintf(stderr, "Trying to fix trx header in %s at 0x%x...\n", mtd, offset);
+
+ block_offset = offset & ~(erasesize - 1);
+ offset -= block_offset;
+
+ fd = mtd_check_open(mtd);
+ if(fd < 0) {
+ fprintf(stderr, "Could not open mtd device: %s\n", mtd);
+ exit(1);
+ }
+
+ if (block_offset + erasesize > mtdsize) {
+ fprintf(stderr, "Offset too large, device size 0x%x\n", mtdsize);
+ exit(1);
+ }
+
+ buf = malloc(erasesize);
+ if (!buf) {
+ perror("malloc");
+ exit(1);
+ }
+
+ res = pread(fd, buf, erasesize, block_offset);
+ if (res != erasesize) {
+ perror("pread");
+ exit(1);
+ }
+
+ trx = (struct trx_header *) (buf + offset);
+ if (trx->magic != STORE32_LE(0x30524448)) {
+ fprintf(stderr, "No trx magic found\n");
+ exit(1);
+ }
+
+ if (trx->len == STORE32_LE(erasesize - offset)) {
+ if (quiet < 2)
+ fprintf(stderr, "Header already fixed, exiting\n");
+ close(fd);
+ return 0;
+ }
+
+ trx->len = STORE32_LE(erasesize - offset);
+
+ trx->crc32 = STORE32_LE(crc32buf((char*) &trx->flag_version, erasesize - offset - 3*4));
+ if (mtd_erase_block(fd, block_offset)) {
+ fprintf(stderr, "Can't erease block at 0x%x (%s)\n", block_offset, strerror(errno));
+ exit(1);
+ }
+
+ if (quiet < 2)
+ fprintf(stderr, "New crc32: 0x%x, rewriting block\n", trx->crc32);
+
+ if (pwrite(fd, buf, erasesize, block_offset) != erasesize) {
+ fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
+ exit(1);
+ }
+
+ if (quiet < 2)
+ fprintf(stderr, "Done.\n");
+
+ close (fd);
+ sync();
+ return 0;
+
+}
+