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-rw-r--r--mtdutils/mtdutils.c46
-rw-r--r--mtdutils/mtdutils.h1
2 files changed, 43 insertions, 4 deletions
diff --git a/mtdutils/mtdutils.c b/mtdutils/mtdutils.c
index 8d32520..18e6a5d 100644
--- a/mtdutils/mtdutils.c
+++ b/mtdutils/mtdutils.c
@@ -47,6 +47,10 @@ struct MtdWriteContext {
char *buffer;
size_t stored;
int fd;
+
+ off_t* bad_block_offsets;
+ int bad_block_alloc;
+ int bad_block_count;
};
typedef struct {
@@ -366,6 +370,10 @@ MtdWriteContext *mtd_write_partition(const MtdPartition *partition)
MtdWriteContext *ctx = (MtdWriteContext*) malloc(sizeof(MtdWriteContext));
if (ctx == NULL) return NULL;
+ ctx->bad_block_offsets = NULL;
+ ctx->bad_block_alloc = 0;
+ ctx->bad_block_count = 0;
+
ctx->buffer = malloc(partition->erase_size);
if (ctx->buffer == NULL) {
free(ctx);
@@ -386,8 +394,20 @@ MtdWriteContext *mtd_write_partition(const MtdPartition *partition)
return ctx;
}
-static int write_block(const MtdPartition *partition, int fd, const char *data)
+static void add_bad_block_offset(MtdWriteContext *ctx, off_t pos) {
+ if (ctx->bad_block_count + 1 > ctx->bad_block_alloc) {
+ ctx->bad_block_alloc = (ctx->bad_block_alloc*2) + 1;
+ ctx->bad_block_offsets = realloc(ctx->bad_block_offsets,
+ ctx->bad_block_alloc * sizeof(off_t));
+ }
+ ctx->bad_block_offsets[ctx->bad_block_count++] = pos;
+}
+
+static int write_block(MtdWriteContext *ctx, const char *data)
{
+ const MtdPartition *partition = ctx->partition;
+ int fd = ctx->fd;
+
off_t pos = lseek(fd, 0, SEEK_CUR);
if (pos == (off_t) -1) return 1;
@@ -395,6 +415,7 @@ static int write_block(const MtdPartition *partition, int fd, const char *data)
while (pos + size <= (int) partition->size) {
loff_t bpos = pos;
if (ioctl(fd, MEMGETBADBLOCK, &bpos) > 0) {
+ add_bad_block_offset(ctx, pos);
fprintf(stderr, "mtd: not writing bad block at 0x%08lx\n", pos);
pos += partition->erase_size;
continue; // Don't try to erase known factory-bad blocks.
@@ -436,6 +457,7 @@ static int write_block(const MtdPartition *partition, int fd, const char *data)
}
// Try to erase it once more as we give up on this block
+ add_bad_block_offset(ctx, pos);
fprintf(stderr, "mtd: skipping write block at 0x%08lx\n", pos);
ioctl(fd, MEMERASE, &erase_info);
pos += partition->erase_size;
@@ -461,13 +483,13 @@ ssize_t mtd_write_data(MtdWriteContext *ctx, const char *data, size_t len)
// If a complete block was accumulated, write it
if (ctx->stored == ctx->partition->erase_size) {
- if (write_block(ctx->partition, ctx->fd, ctx->buffer)) return -1;
+ if (write_block(ctx, ctx->buffer)) return -1;
ctx->stored = 0;
}
// Write complete blocks directly from the user's buffer
while (ctx->stored == 0 && len - wrote >= ctx->partition->erase_size) {
- if (write_block(ctx->partition, ctx->fd, data + wrote)) return -1;
+ if (write_block(ctx, data + wrote)) return -1;
wrote += ctx->partition->erase_size;
}
}
@@ -481,7 +503,7 @@ off_t mtd_erase_blocks(MtdWriteContext *ctx, int blocks)
if (ctx->stored > 0) {
size_t zero = ctx->partition->erase_size - ctx->stored;
memset(ctx->buffer + ctx->stored, 0, zero);
- if (write_block(ctx->partition, ctx->fd, ctx->buffer)) return -1;
+ if (write_block(ctx, ctx->buffer)) return -1;
ctx->stored = 0;
}
@@ -522,7 +544,23 @@ int mtd_write_close(MtdWriteContext *ctx)
// Make sure any pending data gets written
if (mtd_erase_blocks(ctx, 0) == (off_t) -1) r = -1;
if (close(ctx->fd)) r = -1;
+ free(ctx->bad_block_offsets);
free(ctx->buffer);
free(ctx);
return r;
}
+
+/* Return the offset of the first good block at or after pos (which
+ * might be pos itself).
+ */
+off_t mtd_find_write_start(MtdWriteContext *ctx, off_t pos) {
+ int i;
+ for (i = 0; i < ctx->bad_block_count; ++i) {
+ if (ctx->bad_block_offsets[i] == pos) {
+ pos += ctx->partition->erase_size;
+ } else if (ctx->bad_block_offsets[i] > pos) {
+ return pos;
+ }
+ }
+ return pos;
+}
diff --git a/mtdutils/mtdutils.h b/mtdutils/mtdutils.h
index 8d2cb56..528a5bb 100644
--- a/mtdutils/mtdutils.h
+++ b/mtdutils/mtdutils.h
@@ -49,6 +49,7 @@ void mtd_read_close(MtdReadContext *);
MtdWriteContext *mtd_write_partition(const MtdPartition *);
ssize_t mtd_write_data(MtdWriteContext *, const char *data, size_t data_len);
off_t mtd_erase_blocks(MtdWriteContext *, int blocks); /* 0 ok, -1 for all */
+off_t mtd_find_write_start(MtdWriteContext *ctx, off_t pos);
int mtd_write_close(MtdWriteContext *);
#endif // MTDUTILS_H_