/*
* 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 {
int i;
for (i = 0; i < size; ++i) {
if (data[i] != 0) {
return 0; // Success!
}
}
fprintf(stderr, "mtd: read all-zero block at 0x%08lx; skipping\n",
pos);
}
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;
}
if (read >= len) {
return read;
}
// 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;
}