Re: [U-Boot] [PATCH v4 2/2] fastboot: handle flash write to GPT partitions

On Fri, Dec 12, 2014 at 5:51 PM, Steve Rae srae@broadcom.com wrote:

Implement a feature to allow fastboot to write the downloaded image to the space reserved for the Protective MBR and the Primary GUID Partition Table. Additionally, prepare and write the Backup GUID Partition Table.

I've been looking at how to do the same thing here. This is an area that suffers from each vendor doing whatever they want. Using vendor download/flash tools here is painful. They are all different because that is where the value add is. ;) What tool do you use on the host side to create the image? I have seen some vendor code to do it, or you could use parted plus a disk file and extract the partition table from it. I find either method a bit fragile and non-standard IMHO.

The 2 options I've come up with are 1) enable USB MS and use whatever host side tool you like or 2) use the existing "gpt write" command in u-boot and tie that into fastboot "oem format" command. The advantage and disadvantage of the latter is that it hides the partitioning details in u-boot from the user, but requires changing the u-boot env to change partition layout. The partitioning requirements are pretty SOC specific it seems.

I'm not saying we can't support both, but having some standardization here would be good.

Rob

Signed-off-by: Steve Rae srae@broadcom.com

Changes in v4: fix bug with partition_entry_lba in Backup GPT use common static functions

Changes in v3:

• prefer leXX_to_cpu() over cpu_to_leXX()
• enhance calculation of pointer to GPT Entries
• prepare and write the Backup GPT (requested by: Lukasz Majewski l.majewski@samsung.com)

Changes in v2: add validation of the GPT before writing to flash (suggested by: Lukasz Majewski l.majewski@samsung.com)

README | 9 ++++++ common/fb_mmc.c | 26 ++++++++++++++-- disk/part_efi.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/part.h | 20 +++++++++++++ 4 files changed, 145 insertions(+), 3 deletions(-)

diff --git a/README b/README index 4ca04d0..42ece99 100644 --- a/README +++ b/README @@ -1773,6 +1773,15 @@ The following options need to be configured: regarding the non-volatile storage device. Define this to the eMMC device that fastboot should use to store the image.

•           CONFIG_FASTBOOT_GPT_NAME
  

•           The fastboot "flash" command supports writing the downloaded
  

•           image to the Protective MBR and the Primary GUID Partition
  

•           Table. (Additionally, this downloaded image is post-processed
  

•           to generate and write the Backup GUID Partition Table.)
  

•           This occurs when the specified "partition name" on the
  

•           "fastboot flash" command line matches this value.
  

•           Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
  

• 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 fb06d8a..6ea3938 100644 --- a/common/fb_mmc.c +++ b/common/fb_mmc.c @@ -4,12 +4,17 @@

• SPDX-License-Identifier: GPL-2.0+

*/

+#include <config.h> #include <common.h> #include <fb_mmc.h> #include <part.h> #include <aboot.h> #include <sparse_format.h>

+#ifndef CONFIG_FASTBOOT_GPT_NAME +#define CONFIG_FASTBOOT_GPT_NAME GPT_ENTRY_NAME +#endif

/* The 64 defined bytes plus the '\0' */ #define RESPONSE_LEN (64 + 1)

@@ -62,7 +67,6 @@ static void write_raw_image(block_dev_desc_t *dev_desc, disk_partition_t *info, void fb_mmc_flash_write(const char *cmd, void *download_buffer, unsigned int download_bytes, char *response) {

•   int ret;
    block_dev_desc_t *dev_desc;
    disk_partition_t info;
  
  

@@ -76,8 +80,24 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer, return; }

•   ret = get_partition_info_efi_by_name(dev_desc, cmd, &info);
  

•   if (ret) {
  

•   if (strcmp(cmd, CONFIG_FASTBOOT_GPT_NAME) == 0) {
  

•           printf("%s: updating MBR, Primary and Backup GPT(s)\n",
  

•                  __func__);
  

•           if (is_valid_gpt_buf(dev_desc, download_buffer)) {
  

•                   printf("%s: invalid GPT - refusing to write to flash\n",
  

•                          __func__);
  

•                   fastboot_fail("invalid GPT partition");
  

•                   return;
  

•           }
  

•           if (write_mbr_and_gpt_partitions(dev_desc, download_buffer)) {
  

•                   printf("%s: writing GPT partitions failed\n", __func__);
  

•                   fastboot_fail("writing GPT partitions failed");
  

•                   return;
  

•           }
  

•           printf("........ success\n");
  

•           fastboot_okay("");
  

•           return;
  

•   } else if (get_partition_info_efi_by_name(dev_desc, cmd, &info)) {
            error("cannot find partition: '%s'\n", cmd);
            fastboot_fail("cannot find partition");
            return;
  

diff --git a/disk/part_efi.c b/disk/part_efi.c index 2c77f29..338010e 100644 --- a/disk/part_efi.c +++ b/disk/part_efi.c @@ -161,6 +161,8 @@ static void prepare_backup_gpt_header(gpt_header *gpt_h) val = le64_to_cpu(gpt_h->my_lba); gpt_h->my_lba = gpt_h->alternate_lba; gpt_h->alternate_lba = cpu_to_le64(val);

•   gpt_h->partition_entry_lba =
  

•                   cpu_to_le64(le64_to_cpu(gpt_h->last_usable_lba) + 1);
    gpt_h->header_crc32 = 0;
  
    calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
  

@@ -545,6 +547,97 @@ err: free(gpt_h); return ret; }

+int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf) +{

•   gpt_header *gpt_h;
  

•   gpt_entry *gpt_e;
  

•   /* determine start of GPT Header in the buffer */
  

•   gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
  

•                  dev_desc->blksz);
  

•   if (validate_gpt_header(gpt_h, GPT_PRIMARY_PARTITION_TABLE_LBA,
  

•                           dev_desc->lba))
  

•           return -1;
  

•   /* determine start of GPT Entries in the buffer */
  

•   gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
  

•                  dev_desc->blksz);
  

•   if (validate_gpt_entries(gpt_h, gpt_e))
  

•           return -1;
  

•   return 0;
  

+}

+int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void *buf) +{

•   gpt_header *gpt_h;
  

•   gpt_entry *gpt_e;
  

•   int gpt_e_blk_cnt;
  

•   lbaint_t lba;
  

•   int cnt;
  

•   if (is_valid_gpt_buf(dev_desc, buf))
  

•           return -1;
  

•   /* determine start of GPT Header in the buffer */
  

•   gpt_h = buf + (GPT_PRIMARY_PARTITION_TABLE_LBA *
  

•                  dev_desc->blksz);
  

•   /* determine start of GPT Entries in the buffer */
  

•   gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
  

•                  dev_desc->blksz);
  

•   gpt_e_blk_cnt = BLOCK_CNT((le32_to_cpu(gpt_h->num_partition_entries) *
  

•                              le32_to_cpu(gpt_h->sizeof_partition_entry)),
  

•                             dev_desc);
  

•   /* write MBR */
  

•   lba = 0;        /* MBR is always at 0 */
  

•   cnt = 1;        /* MBR (1 block) */
  

•   if (dev_desc->block_write(dev_desc->dev, lba, cnt, buf) != cnt) {
  

•           printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
  

•                  __func__, "MBR", cnt, lba);
  

•           return 1;
  

•   }
  

•   /* write Primary GPT */
  

•   lba = GPT_PRIMARY_PARTITION_TABLE_LBA;
  

•   cnt = 1;        /* GPT Header (1 block) */
  

•   if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
  

•           printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
  

•                  __func__, "Primary GPT Header", cnt, lba);
  

•           return 1;
  

•   }
  

•   lba = le64_to_cpu(gpt_h->partition_entry_lba);
  

•   cnt = gpt_e_blk_cnt;
  

•   if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
  

•           printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
  

•                  __func__, "Primary GPT Entries", cnt, lba);
  

•           return 1;
  

•   }
  

•   prepare_backup_gpt_header(gpt_h);
  

•   /* write Backup GPT */
  

•   lba = le64_to_cpu(gpt_h->partition_entry_lba);
  

•   cnt = gpt_e_blk_cnt;
  

•   if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_e) != cnt) {
  

•           printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
  

•                  __func__, "Backup GPT Entries", cnt, lba);
  

•           return 1;
  

•   }
  

•   lba = le64_to_cpu(gpt_h->my_lba);
  

•   cnt = 1;        /* GPT Header (1 block) */
  

•   if (dev_desc->block_write(dev_desc->dev, lba, cnt, gpt_h) != cnt) {
  

•           printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
  

•                  __func__, "Backup GPT Header", cnt, lba);
  

•           return 1;
  

•   }
  

•   return 0;
  

+} #endif

/* diff --git a/include/part.h b/include/part.h index a496a4a..8ea9b30 100644 --- a/include/part.h +++ b/include/part.h @@ -244,6 +244,26 @@ int gpt_fill_header(block_dev_desc_t *dev_desc, gpt_header *gpt_h, */ int gpt_restore(block_dev_desc_t *dev_desc, char *str_disk_guid, disk_partition_t *partitions, const int parts_count);

+/**

• • is_valid_gpt_buf() - Ensure that the Primary GPT information is valid
• • @param dev_desc - block device descriptor
• • @param buf - buffer which contains the MBR and Primary GPT info
• • @return - '0' on success, otherwise error
• */

+int is_valid_gpt_buf(block_dev_desc_t *dev_desc, void *buf);

+/**

• • write_mbr_and_gpt_partitions() - write MBR, Primary GPT and Backup GPT
• • @param dev_desc - block device descriptor
• • @param buf - buffer which contains the MBR and Primary GPT info
• • @return - '0' on success, otherwise error
• */

+int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void *buf); #endif

#endif /* _PART_H */

1.8.5

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