[U-Boot] [PATCH v2 2/4] fastboot: add support for writing MBR
Petr Kulhavy
brain at jikos.cz
Fri Sep 9 10:27:16 CEST 2016
Add special target "mbr" (otherwise configurable via CONFIG_FASTBOOT_MBR_NAME)
to write MBR partition table.
Partitions are now searched using the generic function which finds any
partiiton by name. For MBR the partition names hda1, sda1, etc. are used.
Signed-off-by: Petr Kulhavy <brain at jikos.cz>
Reviewed-by: Tom Rini <trini at konsulko.com>
---
v1: initial
v2: no change
README | 7 +++++++
common/fb_mmc.c | 40 ++++++++++++++++++++++++++++++++++------
disk/part_dos.c | 20 ++++++++++++++++++++
doc/README.android-fastboot | 37 +++++++++++++++++++++++++++++++++++++
include/part.h | 23 +++++++++++++++++++++++
5 files changed, 121 insertions(+), 6 deletions(-)
diff --git a/README b/README
index 30d7ee3..f6ef8b8 100644
--- a/README
+++ b/README
@@ -1682,6 +1682,13 @@ The following options need to be configured:
"fastboot flash" command line matches this value.
Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
+ CONFIG_FASTBOOT_MBR_NAME
+ The fastboot "flash" command supports writing the downloaded
+ image to DOS MBR.
+ This occurs when the "partition name" specified on the
+ "fastboot flash" command line matches this value.
+ If not defined the default value "mbr" is used.
+
- Journaling Flash filesystem support:
CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
CONFIG_JFFS2_NAND_DEV
diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index a0a4a83..4bc68a7 100644
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -14,15 +14,20 @@
#include <mmc.h>
#include <div64.h>
-#ifndef CONFIG_FASTBOOT_GPT_NAME
+#if defined(CONFIG_EFI_PARTITION) && !defined(CONFIG_FASTBOOT_GPT_NAME)
#define CONFIG_FASTBOOT_GPT_NAME GPT_ENTRY_NAME
#endif
+
+#if defined(CONFIG_DOS_PARTITION) && !defined(CONFIG_FASTBOOT_MBR_NAME)
+#define CONFIG_FASTBOOT_MBR_NAME "mbr"
+#endif
+
struct fb_mmc_sparse {
struct blk_desc *dev_desc;
};
-static int part_get_info_efi_by_name_or_alias(struct blk_desc *dev_desc,
+static int part_get_info_by_name_or_alias(struct blk_desc *dev_desc,
const char *name, disk_partition_t *info)
{
int ret;
@@ -103,6 +108,7 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer,
return;
}
+#ifdef CONFIG_EFI_PARTITION
if (strcmp(cmd, CONFIG_FASTBOOT_GPT_NAME) == 0) {
printf("%s: updating MBR, Primary and Backup GPT(s)\n",
__func__);
@@ -114,14 +120,36 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer,
}
if (write_mbr_and_gpt_partitions(dev_desc, download_buffer)) {
printf("%s: writing GPT partitions failed\n", __func__);
- fastboot_fail(
- "writing GPT partitions failed");
+ fastboot_fail("writing GPT partitions failed");
return;
}
printf("........ success\n");
fastboot_okay("");
return;
- } else if (part_get_info_efi_by_name_or_alias(dev_desc, cmd, &info)) {
+ }
+#endif
+
+#ifdef CONFIG_DOS_PARTITION
+ if (strcmp(cmd, CONFIG_FASTBOOT_MBR_NAME) == 0) {
+ printf("%s: updating MBR\n", __func__);
+ if (is_valid_dos_buf(download_buffer)) {
+ printf("%s: invalid MBR - refusing to write to flash\n",
+ __func__);
+ fastboot_fail("invalid MBR partition");
+ return;
+ }
+ if (write_mbr_partition(dev_desc, download_buffer)) {
+ printf("%s: writing MBR partition failed\n", __func__);
+ fastboot_fail("writing MBR partition failed");
+ return;
+ }
+ printf("........ success\n");
+ fastboot_okay("");
+ return;
+ }
+#endif
+
+ if (part_get_info_by_name_or_alias(dev_desc, cmd, &info)) {
error("cannot find partition: '%s'\n", cmd);
fastboot_fail("cannot find partition");
return;
@@ -172,7 +200,7 @@ void fb_mmc_erase(const char *cmd)
return;
}
- ret = part_get_info_efi_by_name_or_alias(dev_desc, cmd, &info);
+ ret = part_get_info_by_name_or_alias(dev_desc, cmd, &info);
if (ret) {
error("cannot find partition: '%s'", cmd);
fastboot_fail("cannot find partition");
diff --git a/disk/part_dos.c b/disk/part_dos.c
index 8226601..8e6aae5 100644
--- a/disk/part_dos.c
+++ b/disk/part_dos.c
@@ -297,6 +297,26 @@ int part_get_info_dos(struct blk_desc *dev_desc, int part,
return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
}
+int is_valid_dos_buf(void *buf)
+{
+ return test_block_type(buf) == DOS_MBR ? 0 : -1;
+}
+
+int write_mbr_partition(struct blk_desc *dev_desc, void *buf)
+{
+ if (is_valid_dos_buf(buf))
+ return -1;
+
+ /* write MBR */
+ if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
+ printf("%s: failed writing '%s' (1 blks at 0x0)\n",
+ __func__, "MBR");
+ return 1;
+ }
+
+ return 0;
+}
+
U_BOOT_PART_TYPE(dos) = {
.name = "DOS",
.part_type = PART_TYPE_DOS,
diff --git a/doc/README.android-fastboot b/doc/README.android-fastboot
index ce12bc5..dea7066 100644
--- a/doc/README.android-fastboot
+++ b/doc/README.android-fastboot
@@ -59,6 +59,43 @@ To define a partition alias add an environment variable similar to:
fastboot_partition_alias_<alias partition name>=<actual partition name>
Example: fastboot_partition_alias_boot=LNX
+Partition Names
+===============
+The Fastboot implementation in U-boot allows to write images into disk
+partitions (currently on eMMC). Target partitions are referred on the host
+computer by their names.
+
+For GPT/EFI the respective partition name is used.
+
+For MBR the partitions are referred by generic names according to the
+following schema:
+
+ <device type> <device index letter> <partition index>
+
+Example: hda3, sdb1, usbda1
+
+The device type is as follows:
+
+ * IDE, ATAPI and SATA disks: hd
+ * SCSI disks: sd
+ * USB media: usbd
+ * Disk on chip: docd
+ * other: xx
+
+The device index starts from 'a' and refers to the interface (e.g. USB
+controller, SD/MMC controller) or disk index. The partition index starts
+from 1 and describes the partition number on the particular device.
+
+Writing Partition Table
+=======================
+Fastboot also allows to write the partition table to the media. This can be
+done by writing the respective partition table image to a special target
+"gpt" or "mbr". These names can be customized by defining the following
+configuration options:
+
+CONFIG_FASTBOOT_GPT_NAME
+CONFIG_FASTBOOT_MBR_NAME
+
In Action
=========
Enter into fastboot by executing the fastboot command in u-boot and you
diff --git a/include/part.h b/include/part.h
index bd8fd49..b17c219 100644
--- a/include/part.h
+++ b/include/part.h
@@ -351,4 +351,27 @@ int gpt_verify_partitions(struct blk_desc *dev_desc,
gpt_header *gpt_head, gpt_entry **gpt_pte);
#endif
+#ifdef CONFIG_DOS_PARTITION
+/**
+ * is_valid_dos_buf() - Ensure that a DOS MBR image is valid
+ *
+ * @param buf - buffer which contains the MBR
+ *
+ * @return - '0' on success, otherwise error
+ */
+int is_valid_dos_buf(void *buf);
+
+/**
+ * write_mbr_partition() - write DOS MBR
+ *
+ * @param dev_desc - block device descriptor
+ * @param buf - buffer which contains the MBR
+ *
+ * @return - '0' on success, otherwise error
+ */
+int write_mbr_partition(struct blk_desc *dev_desc, void *buf);
+
+#endif
+
+
#endif /* _PART_H */
--
2.7.4
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