--- /dev/null
+Embedded device command line partition
+=====================================================================
+
+Read block device partition table from command line.
+The partition used for fixed block device (eMMC) embedded device.
+It is no MBR, save storage space. Bootloader can be easily accessed
+by absolute address of data on the block device.
+Users can easily change the partition.
+
+The format for the command line is just like mtdparts:
+
+blkdevparts=<blkdev-def>[;<blkdev-def>]
+ <blkdev-def> := <blkdev-id>:<partdef>[,<partdef>]
+ <partdef> := <size>[@<offset>](part-name)
+
+<blkdev-id>
+ block device disk name, embedded device used fixed block device,
+ it's disk name also fixed. such as: mmcblk0, mmcblk1, mmcblk0boot0.
+
+<size>
+ partition size, in bytes, such as: 512, 1m, 1G.
+
+<offset>
+ partition start address, in bytes.
+
+(part-name)
+ partition name, kernel send uevent with "PARTNAME". application can create
+ a link to block device partition with the name "PARTNAME".
+ user space application can access partition by partition name.
+
+Example:
+ eMMC disk name is "mmcblk0" and "mmcblk0boot0"
+
+ bootargs:
+ 'blkdevparts=mmcblk0:1G(data0),1G(data1),-;mmcblk0boot0:1m(boot),-(kernel)'
+
+ dmesg:
+ mmcblk0: p1(data0) p2(data1) p3()
+ mmcblk0boot0: p1(boot) p2(kernel)
See Documentation/cgroups/blkio-controller.txt for more information.
+config CMDLINE_PARSER
+ bool "Block device command line partition parser"
+ default n
+ ---help---
+ Parsing command line, get the partitions information.
+
menu "Partition Types"
source "block/partitions/Kconfig"
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o
+obj-$(CONFIG_CMDLINE_PARSER) += cmdline-parser.o
--- /dev/null
+/*
+ * Parse command line, get partition information
+ *
+ * Written by Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ */
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/cmdline-parser.h>
+
+static int parse_subpart(struct cmdline_subpart **subpart, char *partdef)
+{
+ int ret = 0;
+ struct cmdline_subpart *new_subpart;
+
+ *subpart = NULL;
+
+ new_subpart = kzalloc(sizeof(struct cmdline_subpart), GFP_KERNEL);
+ if (!new_subpart)
+ return -ENOMEM;
+
+ if (*partdef == '-') {
+ new_subpart->size = (sector_t)(~0ULL);
+ partdef++;
+ } else {
+ new_subpart->size = (sector_t)memparse(partdef, &partdef);
+ if (new_subpart->size < (sector_t)PAGE_SIZE) {
+ pr_warn("cmdline partition size is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ if (*partdef == '@') {
+ partdef++;
+ new_subpart->from = (sector_t)memparse(partdef, &partdef);
+ } else {
+ new_subpart->from = (sector_t)(~0ULL);
+ }
+
+ if (*partdef == '(') {
+ int length;
+ char *next = strchr(++partdef, ')');
+
+ if (!next) {
+ pr_warn("cmdline partition format is invalid.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ length = min_t(int, next - partdef,
+ sizeof(new_subpart->name) - 1);
+ strncpy(new_subpart->name, partdef, length);
+ new_subpart->name[length] = '\0';
+
+ partdef = ++next;
+ } else
+ new_subpart->name[0] = '\0';
+
+ new_subpart->flags = 0;
+
+ if (!strncmp(partdef, "ro", 2)) {
+ new_subpart->flags |= PF_RDONLY;
+ partdef += 2;
+ }
+
+ if (!strncmp(partdef, "lk", 2)) {
+ new_subpart->flags |= PF_POWERUP_LOCK;
+ partdef += 2;
+ }
+
+ *subpart = new_subpart;
+ return 0;
+fail:
+ kfree(new_subpart);
+ return ret;
+}
+
+static void free_subpart(struct cmdline_parts *parts)
+{
+ struct cmdline_subpart *subpart;
+
+ while (parts->subpart) {
+ subpart = parts->subpart;
+ parts->subpart = subpart->next_subpart;
+ kfree(subpart);
+ }
+}
+
+static int parse_parts(struct cmdline_parts **parts, const char *bdevdef)
+{
+ int ret = -EINVAL;
+ char *next;
+ int length;
+ struct cmdline_subpart **next_subpart;
+ struct cmdline_parts *newparts;
+ char buf[BDEVNAME_SIZE + 32 + 4];
+
+ *parts = NULL;
+
+ newparts = kzalloc(sizeof(struct cmdline_parts), GFP_KERNEL);
+ if (!newparts)
+ return -ENOMEM;
+
+ next = strchr(bdevdef, ':');
+ if (!next) {
+ pr_warn("cmdline partition has no block device.");
+ goto fail;
+ }
+
+ length = min_t(int, next - bdevdef, sizeof(newparts->name) - 1);
+ strncpy(newparts->name, bdevdef, length);
+ newparts->name[length] = '\0';
+ newparts->nr_subparts = 0;
+
+ next_subpart = &newparts->subpart;
+
+ while (next && *(++next)) {
+ bdevdef = next;
+ next = strchr(bdevdef, ',');
+
+ length = (!next) ? (sizeof(buf) - 1) :
+ min_t(int, next - bdevdef, sizeof(buf) - 1);
+
+ strncpy(buf, bdevdef, length);
+ buf[length] = '\0';
+
+ ret = parse_subpart(next_subpart, buf);
+ if (ret)
+ goto fail;
+
+ newparts->nr_subparts++;
+ next_subpart = &(*next_subpart)->next_subpart;
+ }
+
+ if (!newparts->subpart) {
+ pr_warn("cmdline partition has no valid partition.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ *parts = newparts;
+
+ return 0;
+fail:
+ free_subpart(newparts);
+ kfree(newparts);
+ return ret;
+}
+
+void cmdline_parts_free(struct cmdline_parts **parts)
+{
+ struct cmdline_parts *next_parts;
+
+ while (*parts) {
+ next_parts = (*parts)->next_parts;
+ free_subpart(*parts);
+ kfree(*parts);
+ *parts = next_parts;
+ }
+}
+
+int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline)
+{
+ int ret;
+ char *buf;
+ char *pbuf;
+ char *next;
+ struct cmdline_parts **next_parts;
+
+ *parts = NULL;
+
+ next = pbuf = buf = kstrdup(cmdline, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ next_parts = parts;
+
+ while (next && *pbuf) {
+ next = strchr(pbuf, ';');
+ if (next)
+ *next = '\0';
+
+ ret = parse_parts(next_parts, pbuf);
+ if (ret)
+ goto fail;
+
+ if (next)
+ pbuf = ++next;
+
+ next_parts = &(*next_parts)->next_parts;
+ }
+
+ if (!*parts) {
+ pr_warn("cmdline partition has no valid partition.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = 0;
+done:
+ kfree(buf);
+ return ret;
+
+fail:
+ cmdline_parts_free(parts);
+ goto done;
+}
+
+struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
+ const char *bdev)
+{
+ while (parts && strncmp(bdev, parts->name, sizeof(parts->name)))
+ parts = parts->next_parts;
+ return parts;
+}
+
+/*
+ * add_part()
+ * 0 success.
+ * 1 can not add so many partitions.
+ */
+void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
+ int slot,
+ int (*add_part)(int, struct cmdline_subpart *, void *),
+ void *param)
+
+{
+ sector_t from = 0;
+ struct cmdline_subpart *subpart;
+
+ for (subpart = parts->subpart; subpart;
+ subpart = subpart->next_subpart, slot++) {
+ if (subpart->from == (sector_t)(~0ULL))
+ subpart->from = from;
+ else
+ from = subpart->from;
+
+ if (from >= disk_size)
+ break;
+
+ if (subpart->size > (disk_size - from))
+ subpart->size = disk_size - from;
+
+ from += subpart->size;
+
+ if (add_part(slot, subpart, param))
+ break;
+ }
+}
partition table format used by Motorola Delta machines (using
sysv68).
Otherwise, say N.
+
+config CMDLINE_PARTITION
+ bool "Command line partition support" if PARTITION_ADVANCED
+ select CMDLINE_PARSER
+ help
+ Say Y here if you would read the partitions table from bootargs.
+ The format for the command line is just like mtdparts.
obj-$(CONFIG_AMIGA_PARTITION) += amiga.o
obj-$(CONFIG_ATARI_PARTITION) += atari.o
obj-$(CONFIG_AIX_PARTITION) += aix.o
+obj-$(CONFIG_CMDLINE_PARTITION) += cmdline.o
obj-$(CONFIG_MAC_PARTITION) += mac.o
obj-$(CONFIG_LDM_PARTITION) += ldm.o
obj-$(CONFIG_MSDOS_PARTITION) += msdos.o
#include "efi.h"
#include "karma.h"
#include "sysv68.h"
+#include "cmdline.h"
int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
adfspart_check_ADFS,
#endif
+#ifdef CONFIG_CMDLINE_PARTITION
+ cmdline_partition,
+#endif
#ifdef CONFIG_EFI_PARTITION
efi_partition, /* this must come before msdos */
#endif
--- /dev/null
+/*
+ * Copyright (C) 2013 HUAWEI
+ * Author: Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ * Read block device partition table from command line.
+ * The partition used for fixed block device (eMMC) embedded device.
+ * It is no MBR, save storage space. Bootloader can be easily accessed
+ * by absolute address of data on the block device.
+ * Users can easily change the partition.
+ *
+ * The format for the command line is just like mtdparts.
+ *
+ * Verbose config please reference "Documentation/block/cmdline-partition.txt"
+ *
+ */
+
+#include <linux/cmdline-parser.h>
+
+#include "check.h"
+#include "cmdline.h"
+
+static char *cmdline;
+static struct cmdline_parts *bdev_parts;
+
+static int add_part(int slot, struct cmdline_subpart *subpart, void *param)
+{
+ int label_min;
+ struct partition_meta_info *info;
+ char tmp[sizeof(info->volname) + 4];
+ struct parsed_partitions *state = (struct parsed_partitions *)param;
+
+ if (slot >= state->limit)
+ return 1;
+
+ put_partition(state, slot, subpart->from >> 9,
+ subpart->size >> 9);
+
+ info = &state->parts[slot].info;
+
+ label_min = min_t(int, sizeof(info->volname) - 1,
+ sizeof(subpart->name));
+ strncpy(info->volname, subpart->name, label_min);
+ info->volname[label_min] = '\0';
+
+ snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+
+ state->parts[slot].has_info = true;
+
+ return 0;
+}
+
+static int __init cmdline_parts_setup(char *s)
+{
+ cmdline = s;
+ return 1;
+}
+__setup("blkdevparts=", cmdline_parts_setup);
+
+/*
+ * Purpose: allocate cmdline partitions.
+ * Returns:
+ * -1 if unable to read the partition table
+ * 0 if this isn't our partition table
+ * 1 if successful
+ */
+int cmdline_partition(struct parsed_partitions *state)
+{
+ sector_t disk_size;
+ char bdev[BDEVNAME_SIZE];
+ struct cmdline_parts *parts;
+
+ if (cmdline) {
+ if (bdev_parts)
+ cmdline_parts_free(&bdev_parts);
+
+ if (cmdline_parts_parse(&bdev_parts, cmdline)) {
+ cmdline = NULL;
+ return -1;
+ }
+ cmdline = NULL;
+ }
+
+ if (!bdev_parts)
+ return 0;
+
+ bdevname(state->bdev, bdev);
+ parts = cmdline_parts_find(bdev_parts, bdev);
+ if (!parts)
+ return 0;
+
+ disk_size = get_capacity(state->bdev->bd_disk) << 9;
+
+ cmdline_parts_set(parts, disk_size, 1, add_part, (void *)state);
+
+ strlcat(state->pp_buf, "\n", PAGE_SIZE);
+
+ return 1;
+}
--- /dev/null
+
+int cmdline_partition(struct parsed_partitions *state);
--- /dev/null
+/*
+ * Parsing command line, get the partitions information.
+ *
+ * Written by Cai Zhiyong <caizhiyong@huawei.com>
+ *
+ */
+#ifndef CMDLINEPARSEH
+#define CMDLINEPARSEH
+
+#include <linux/blkdev.h>
+
+/* partition flags */
+#define PF_RDONLY 0x01 /* Device is read only */
+#define PF_POWERUP_LOCK 0x02 /* Always locked after reset */
+
+struct cmdline_subpart {
+ char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
+ sector_t from;
+ sector_t size;
+ int flags;
+ struct cmdline_subpart *next_subpart;
+};
+
+struct cmdline_parts {
+ char name[BDEVNAME_SIZE]; /* block device, such as 'mmcblk0' */
+ unsigned int nr_subparts;
+ struct cmdline_subpart *subpart;
+ struct cmdline_parts *next_parts;
+};
+
+void cmdline_parts_free(struct cmdline_parts **parts);
+
+int cmdline_parts_parse(struct cmdline_parts **parts, const char *cmdline);
+
+struct cmdline_parts *cmdline_parts_find(struct cmdline_parts *parts,
+ const char *bdev);
+
+void cmdline_parts_set(struct cmdline_parts *parts, sector_t disk_size,
+ int slot,
+ int (*add_part)(int, struct cmdline_subpart *, void *),
+ void *param);
+
+#endif /* CMDLINEPARSEH */
projects / linux-platform-drivers-x86.git / commitdiff