make offsets in firmware update header not point to bad blocks
(This is being cherry-picked from master.)
hboot will apparently fail to install if the first block of the image
(the one pointed to by the offset in the block 0 header) is a bad
block. (Hopefully it handles subsequent bad blocks.)
This change makes the MTD write code keep track of the bad blocks it
has skipped over, so that the offset in the header can be adjusted to
be the address of the first successfully written block.
http://b/2358012 - passion: failure to flash hboot (bad blocks?)
diff --git a/bootloader.c b/bootloader.c
index de441e1..bc79bee 100644
--- a/bootloader.c
+++ b/bootloader.c
@@ -198,7 +198,7 @@
header.version = UPDATE_VERSION;
header.size = header_size;
- header.image_offset = mtd_erase_blocks(write, 0);
+ off_t image_start_pos = mtd_erase_blocks(write, 0);
header.image_length = update_length;
if ((int) header.image_offset == -1 ||
mtd_write_data(write, update, update_length) != update_length) {
@@ -206,6 +206,8 @@
mtd_write_close(write);
return -1;
}
+ off_t busy_start_pos = mtd_erase_blocks(write, 0);
+ header.image_offset = mtd_find_write_start(write, image_start_pos);
header.bitmap_width = bitmap_width;
header.bitmap_height = bitmap_height;
@@ -213,7 +215,6 @@
int bitmap_length = (bitmap_bpp + 7) / 8 * bitmap_width * bitmap_height;
- header.busy_bitmap_offset = mtd_erase_blocks(write, 0);
header.busy_bitmap_length = busy_bitmap != NULL ? bitmap_length : 0;
if ((int) header.busy_bitmap_offset == -1 ||
mtd_write_data(write, busy_bitmap, bitmap_length) != bitmap_length) {
@@ -221,8 +222,9 @@
mtd_write_close(write);
return -1;
}
+ off_t fail_start_pos = mtd_erase_blocks(write, 0);
+ header.busy_bitmap_offset = mtd_find_write_start(write, busy_start_pos);
- header.fail_bitmap_offset = mtd_erase_blocks(write, 0);
header.fail_bitmap_length = fail_bitmap != NULL ? bitmap_length : 0;
if ((int) header.fail_bitmap_offset == -1 ||
mtd_write_data(write, fail_bitmap, bitmap_length) != bitmap_length) {
@@ -230,6 +232,8 @@
mtd_write_close(write);
return -1;
}
+ mtd_erase_blocks(write, 0);
+ header.fail_bitmap_offset = mtd_find_write_start(write, fail_start_pos);
/* Write the header last, after all the blocks it refers to, so that
* when the magic number is installed everything is valid.
@@ -252,7 +256,7 @@
return -1;
}
- if (mtd_erase_blocks(write, 0) != (off_t) header.image_offset) {
+ if (mtd_erase_blocks(write, 0) != image_start_pos) {
LOGE("Misalignment rewriting %s\n(%s)\n", CACHE_NAME, strerror(errno));
mtd_write_close(write);
return -1;
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 @@
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 *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 @@
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 @@
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 @@
}
// 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 @@
// 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 @@
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 @@
// 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 @@
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_