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-rw-r--r--mtdutils/mtdutils.c510
1 files changed, 510 insertions, 0 deletions
diff --git a/mtdutils/mtdutils.c b/mtdutils/mtdutils.c
new file mode 100644
index 0000000..2b0106f
--- /dev/null
+++ b/mtdutils/mtdutils.c
@@ -0,0 +1,510 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/mount.h> // for _IOW, _IOR, mount()
+#include <sys/stat.h>
+#include <mtd/mtd-user.h>
+#undef NDEBUG
+#include <assert.h>
+
+#include "mtdutils.h"
+
+struct MtdPartition {
+ int device_index;
+ unsigned int size;
+ unsigned int erase_size;
+ char *name;
+};
+
+struct MtdReadContext {
+ const MtdPartition *partition;
+ char *buffer;
+ size_t consumed;
+ int fd;
+};
+
+struct MtdWriteContext {
+ const MtdPartition *partition;
+ char *buffer;
+ size_t stored;
+ int fd;
+};
+
+typedef struct {
+ MtdPartition *partitions;
+ int partitions_allocd;
+ int partition_count;
+} MtdState;
+
+static MtdState g_mtd_state = {
+ NULL, // partitions
+ 0, // partitions_allocd
+ -1 // partition_count
+};
+
+#define MTD_PROC_FILENAME "/proc/mtd"
+
+int
+mtd_scan_partitions()
+{
+ char buf[2048];
+ const char *bufp;
+ int fd;
+ int i;
+ ssize_t nbytes;
+
+ if (g_mtd_state.partitions == NULL) {
+ const int nump = 32;
+ MtdPartition *partitions = malloc(nump * sizeof(*partitions));
+ if (partitions == NULL) {
+ errno = ENOMEM;
+ return -1;
+ }
+ g_mtd_state.partitions = partitions;
+ g_mtd_state.partitions_allocd = nump;
+ memset(partitions, 0, nump * sizeof(*partitions));
+ }
+ g_mtd_state.partition_count = 0;
+
+ /* Initialize all of the entries to make things easier later.
+ * (Lets us handle sparsely-numbered partitions, which
+ * may not even be possible.)
+ */
+ for (i = 0; i < g_mtd_state.partitions_allocd; i++) {
+ MtdPartition *p = &g_mtd_state.partitions[i];
+ if (p->name != NULL) {
+ free(p->name);
+ p->name = NULL;
+ }
+ p->device_index = -1;
+ }
+
+ /* Open and read the file contents.
+ */
+ fd = open(MTD_PROC_FILENAME, O_RDONLY);
+ if (fd < 0) {
+ goto bail;
+ }
+ nbytes = read(fd, buf, sizeof(buf) - 1);
+ close(fd);
+ if (nbytes < 0) {
+ goto bail;
+ }
+ buf[nbytes] = '\0';
+
+ /* Parse the contents of the file, which looks like:
+ *
+ * # cat /proc/mtd
+ * dev: size erasesize name
+ * mtd0: 00080000 00020000 "bootloader"
+ * mtd1: 00400000 00020000 "mfg_and_gsm"
+ * mtd2: 00400000 00020000 "0000000c"
+ * mtd3: 00200000 00020000 "0000000d"
+ * mtd4: 04000000 00020000 "system"
+ * mtd5: 03280000 00020000 "userdata"
+ */
+ bufp = buf;
+ while (nbytes > 0) {
+ int mtdnum, mtdsize, mtderasesize;
+ int matches;
+ char mtdname[64];
+ mtdname[0] = '\0';
+ mtdnum = -1;
+
+ matches = sscanf(bufp, "mtd%d: %x %x \"%63[^\"]",
+ &mtdnum, &mtdsize, &mtderasesize, mtdname);
+ /* This will fail on the first line, which just contains
+ * column headers.
+ */
+ if (matches == 4) {
+ MtdPartition *p = &g_mtd_state.partitions[mtdnum];
+ p->device_index = mtdnum;
+ p->size = mtdsize;
+ p->erase_size = mtderasesize;
+ p->name = strdup(mtdname);
+ if (p->name == NULL) {
+ errno = ENOMEM;
+ goto bail;
+ }
+ g_mtd_state.partition_count++;
+ }
+
+ /* Eat the line.
+ */
+ while (nbytes > 0 && *bufp != '\n') {
+ bufp++;
+ nbytes--;
+ }
+ if (nbytes > 0) {
+ bufp++;
+ nbytes--;
+ }
+ }
+
+ return g_mtd_state.partition_count;
+
+bail:
+ // keep "partitions" around so we can free the names on a rescan.
+ g_mtd_state.partition_count = -1;
+ return -1;
+}
+
+const MtdPartition *
+mtd_find_partition_by_name(const char *name)
+{
+ if (g_mtd_state.partitions != NULL) {
+ int i;
+ for (i = 0; i < g_mtd_state.partitions_allocd; i++) {
+ MtdPartition *p = &g_mtd_state.partitions[i];
+ if (p->device_index >= 0 && p->name != NULL) {
+ if (strcmp(p->name, name) == 0) {
+ return p;
+ }
+ }
+ }
+ }
+ return NULL;
+}
+
+int
+mtd_mount_partition(const MtdPartition *partition, const char *mount_point,
+ const char *filesystem, int read_only)
+{
+ const unsigned long flags = MS_NOATIME | MS_NODEV | MS_NODIRATIME;
+ char devname[64];
+ int rv = -1;
+
+ sprintf(devname, "/dev/block/mtdblock%d", partition->device_index);
+ if (!read_only) {
+ rv = mount(devname, mount_point, filesystem, flags, NULL);
+ }
+ if (read_only || rv < 0) {
+ rv = mount(devname, mount_point, filesystem, flags | MS_RDONLY, 0);
+ if (rv < 0) {
+ printf("Failed to mount %s on %s: %s\n",
+ devname, mount_point, strerror(errno));
+ } else {
+ printf("Mount %s on %s read-only\n", devname, mount_point);
+ }
+ }
+#if 1 //TODO: figure out why this is happening; remove include of stat.h
+ if (rv >= 0) {
+ /* For some reason, the x bits sometimes aren't set on the root
+ * of mounted volumes.
+ */
+ struct stat st;
+ rv = stat(mount_point, &st);
+ if (rv < 0) {
+ return rv;
+ }
+ mode_t new_mode = st.st_mode | S_IXUSR | S_IXGRP | S_IXOTH;
+ if (new_mode != st.st_mode) {
+printf("Fixing execute permissions for %s\n", mount_point);
+ rv = chmod(mount_point, new_mode);
+ if (rv < 0) {
+ printf("Couldn't fix permissions for %s: %s\n",
+ mount_point, strerror(errno));
+ }
+ }
+ }
+#endif
+ return rv;
+}
+
+int
+mtd_partition_info(const MtdPartition *partition,
+ size_t *total_size, size_t *erase_size, size_t *write_size)
+{
+ char mtddevname[32];
+ sprintf(mtddevname, "/dev/mtd/mtd%d", partition->device_index);
+ int fd = open(mtddevname, O_RDONLY);
+ if (fd < 0) return -1;
+
+ struct mtd_info_user mtd_info;
+ int ret = ioctl(fd, MEMGETINFO, &mtd_info);
+ close(fd);
+ if (ret < 0) return -1;
+
+ if (total_size != NULL) *total_size = mtd_info.size;
+ if (erase_size != NULL) *erase_size = mtd_info.erasesize;
+ if (write_size != NULL) *write_size = mtd_info.writesize;
+ return 0;
+}
+
+MtdReadContext *mtd_read_partition(const MtdPartition *partition)
+{
+ MtdReadContext *ctx = (MtdReadContext*) malloc(sizeof(MtdReadContext));
+ if (ctx == NULL) return NULL;
+
+ ctx->buffer = malloc(partition->erase_size);
+ if (ctx->buffer == NULL) {
+ free(ctx);
+ return NULL;
+ }
+
+ char mtddevname[32];
+ sprintf(mtddevname, "/dev/mtd/mtd%d", partition->device_index);
+ ctx->fd = open(mtddevname, O_RDONLY);
+ if (ctx->fd < 0) {
+ free(ctx);
+ free(ctx->buffer);
+ return NULL;
+ }
+
+ ctx->partition = partition;
+ ctx->consumed = partition->erase_size;
+ return ctx;
+}
+
+static int read_block(const MtdPartition *partition, int fd, char *data)
+{
+ struct mtd_ecc_stats before, after;
+ if (ioctl(fd, ECCGETSTATS, &before)) {
+ fprintf(stderr, "mtd: ECCGETSTATS error (%s)\n", strerror(errno));
+ return -1;
+ }
+
+ off_t pos = lseek(fd, 0, SEEK_CUR);
+ ssize_t size = partition->erase_size;
+ while (pos + size <= (int) partition->size) {
+ if (lseek(fd, pos, SEEK_SET) != pos || read(fd, data, size) != size) {
+ fprintf(stderr, "mtd: read error at 0x%08lx (%s)\n",
+ pos, strerror(errno));
+ } else if (ioctl(fd, ECCGETSTATS, &after)) {
+ fprintf(stderr, "mtd: ECCGETSTATS error (%s)\n", strerror(errno));
+ return -1;
+ } else if (after.failed != before.failed) {
+ fprintf(stderr, "mtd: ECC errors (%d soft, %d hard) at 0x%08lx\n",
+ after.corrected - before.corrected,
+ after.failed - before.failed, pos);
+ } else {
+ return 0; // Success!
+ }
+
+ pos += partition->erase_size;
+ }
+
+ errno = ENOSPC;
+ return -1;
+}
+
+ssize_t mtd_read_data(MtdReadContext *ctx, char *data, size_t len)
+{
+ ssize_t read = 0;
+ while (read < (int) len) {
+ if (ctx->consumed < ctx->partition->erase_size) {
+ size_t avail = ctx->partition->erase_size - ctx->consumed;
+ size_t copy = len - read < avail ? len - read : avail;
+ memcpy(data + read, ctx->buffer + ctx->consumed, copy);
+ ctx->consumed += copy;
+ read += copy;
+ }
+
+ // Read complete blocks directly into the user's buffer
+ while (ctx->consumed == ctx->partition->erase_size &&
+ len - read >= ctx->partition->erase_size) {
+ if (read_block(ctx->partition, ctx->fd, data + read)) return -1;
+ read += ctx->partition->erase_size;
+ }
+
+ // Read the next block into the buffer
+ if (ctx->consumed == ctx->partition->erase_size && read < (int) len) {
+ if (read_block(ctx->partition, ctx->fd, ctx->buffer)) return -1;
+ ctx->consumed = 0;
+ }
+ }
+
+ return read;
+}
+
+void mtd_read_close(MtdReadContext *ctx)
+{
+ close(ctx->fd);
+ free(ctx->buffer);
+ free(ctx);
+}
+
+MtdWriteContext *mtd_write_partition(const MtdPartition *partition)
+{
+ MtdWriteContext *ctx = (MtdWriteContext*) malloc(sizeof(MtdWriteContext));
+ if (ctx == NULL) return NULL;
+
+ ctx->buffer = malloc(partition->erase_size);
+ if (ctx->buffer == NULL) {
+ free(ctx);
+ return NULL;
+ }
+
+ char mtddevname[32];
+ sprintf(mtddevname, "/dev/mtd/mtd%d", partition->device_index);
+ ctx->fd = open(mtddevname, O_RDWR);
+ if (ctx->fd < 0) {
+ free(ctx->buffer);
+ free(ctx);
+ return NULL;
+ }
+
+ ctx->partition = partition;
+ ctx->stored = 0;
+ return ctx;
+}
+
+static int write_block(const MtdPartition *partition, int fd, const char *data)
+{
+ off_t pos = lseek(fd, 0, SEEK_CUR);
+ if (pos == (off_t) -1) return 1;
+
+ ssize_t size = partition->erase_size;
+ while (pos + size <= (int) partition->size) {
+ loff_t bpos = pos;
+ if (ioctl(fd, MEMGETBADBLOCK, &bpos) > 0) {
+ 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.
+ }
+
+ struct erase_info_user erase_info;
+ erase_info.start = pos;
+ erase_info.length = size;
+ int retry;
+ for (retry = 0; retry < 2; ++retry) {
+ if (ioctl(fd, MEMERASE, &erase_info) < 0) {
+ fprintf(stderr, "mtd: erase failure at 0x%08lx (%s)\n",
+ pos, strerror(errno));
+ continue;
+ }
+ if (lseek(fd, pos, SEEK_SET) != pos ||
+ write(fd, data, size) != size) {
+ fprintf(stderr, "mtd: write error at 0x%08lx (%s)\n",
+ pos, strerror(errno));
+ }
+
+ char verify[size];
+ if (lseek(fd, pos, SEEK_SET) != pos ||
+ read(fd, verify, size) != size) {
+ fprintf(stderr, "mtd: re-read error at 0x%08lx (%s)\n",
+ pos, strerror(errno));
+ continue;
+ }
+ if (memcmp(data, verify, size) != 0) {
+ fprintf(stderr, "mtd: verification error at 0x%08lx (%s)\n",
+ pos, strerror(errno));
+ continue;
+ }
+
+ if (retry > 0) {
+ fprintf(stderr, "mtd: wrote block after %d retries\n", retry);
+ }
+ return 0; // Success!
+ }
+
+ // Try to erase it once more as we give up on this block
+ fprintf(stderr, "mtd: skipping write block at 0x%08lx\n", pos);
+ ioctl(fd, MEMERASE, &erase_info);
+ pos += partition->erase_size;
+ }
+
+ // Ran out of space on the device
+ errno = ENOSPC;
+ return -1;
+}
+
+ssize_t mtd_write_data(MtdWriteContext *ctx, const char *data, size_t len)
+{
+ size_t wrote = 0;
+ while (wrote < len) {
+ // Coalesce partial writes into complete blocks
+ if (ctx->stored > 0 || len - wrote < ctx->partition->erase_size) {
+ size_t avail = ctx->partition->erase_size - ctx->stored;
+ size_t copy = len - wrote < avail ? len - wrote : avail;
+ memcpy(ctx->buffer + ctx->stored, data + wrote, copy);
+ ctx->stored += copy;
+ wrote += copy;
+ }
+
+ // 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;
+ 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;
+ wrote += ctx->partition->erase_size;
+ }
+ }
+
+ return wrote;
+}
+
+off_t mtd_erase_blocks(MtdWriteContext *ctx, int blocks)
+{
+ // Zero-pad and write any pending data to get us to a block boundary
+ 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;
+ ctx->stored = 0;
+ }
+
+ off_t pos = lseek(ctx->fd, 0, SEEK_CUR);
+ if ((off_t) pos == (off_t) -1) return pos;
+
+ const int total = (ctx->partition->size - pos) / ctx->partition->erase_size;
+ if (blocks < 0) blocks = total;
+ if (blocks > total) {
+ errno = ENOSPC;
+ return -1;
+ }
+
+ // Erase the specified number of blocks
+ while (blocks-- > 0) {
+ loff_t bpos = pos;
+ if (ioctl(ctx->fd, MEMGETBADBLOCK, &bpos) > 0) {
+ fprintf(stderr, "mtd: not erasing bad block at 0x%08lx\n", pos);
+ pos += ctx->partition->erase_size;
+ continue; // Don't try to erase known factory-bad blocks.
+ }
+
+ struct erase_info_user erase_info;
+ erase_info.start = pos;
+ erase_info.length = ctx->partition->erase_size;
+ if (ioctl(ctx->fd, MEMERASE, &erase_info) < 0) {
+ fprintf(stderr, "mtd: erase failure at 0x%08lx\n", pos);
+ }
+ pos += ctx->partition->erase_size;
+ }
+
+ return pos;
+}
+
+int mtd_write_close(MtdWriteContext *ctx)
+{
+ int r = 0;
+ // 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->buffer);
+ free(ctx);
+ return r;
+}
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