[U-Boot] [PATCH v3] fastboot: handle flash write to GPT partitions
Lukasz Majewski
l.majewski at samsung.com
Thu Dec 11 11:12:21 CET 2014
Hi Steve,
> 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.
>
> Signed-off-by: Steve Rae <srae at broadcom.com>
> ---
>
> 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 at samsung.com>)
>
> Changes in v2:
> add validation of the GPT before writing to flash
> (suggested by: Lukasz Majewski <l.majewski at samsung.com>)
>
> README | 9 +++++
> common/fb_mmc.c | 26 ++++++++++++--
> disk/part_efi.c | 107
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> include/part.h | 20 +++++++++++ 4 files changed, 159 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..5acc8df 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(download_buffer,
> dev_desc->blksz)) {
> + 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 efed58f..9cc04da 100644
> --- a/disk/part_efi.c
> +++ b/disk/part_efi.c
> @@ -455,6 +455,113 @@ err:
> free(gpt_h);
> return ret;
> }
> +
> +int is_valid_gpt_buf(void *buf, unsigned long blksz)
Please see my comment to v2 regarding this function.
> +{
> + int rc = 0;
> + gpt_header *gpt_h;
> + gpt_entry *gpt_e;
> + gpt_header gpt_hdr;
> + uint32_t calc_crc32;
> +
> + /* GPT Header starts at "LBA[1]" in the buffer */
> + gpt_h = buf + blksz;
> + if (le64_to_cpu(gpt_h->signature) != GPT_HEADER_SIGNATURE) {
> + printf("%s: 'signature' is invalid\n", __func__);
> + return -1;
> + }
> +
> + memcpy(&gpt_hdr, gpt_h, sizeof(gpt_header));
> + gpt_hdr.header_crc32 = 0;
> + calc_crc32 = efi_crc32((const unsigned char *)&gpt_hdr,
> + le32_to_cpu(gpt_h->header_size));
> + if (le32_to_cpu(gpt_h->header_crc32) != calc_crc32) {
> + printf("%s: 'header_crc32' is invalid\n", __func__);
> + rc += 1;
> + }
> +
> + /* determine start of GPT Entries in the buffer */
> + gpt_e = buf + (le64_to_cpu(gpt_h->partition_entry_lba) *
> blksz);
> + calc_crc32 = efi_crc32((const unsigned char *)gpt_e,
> +
> le32_to_cpu(gpt_h->num_partition_entries) *
> +
> le32_to_cpu(gpt_h->sizeof_partition_entry));
> + if (le32_to_cpu(gpt_h->partition_entry_array_crc32) !=
> calc_crc32) {
> + printf("%s: 'partition_entry_array_crc32' is
> invalid\n",
> + __func__);
> + rc += 1;
> + }
> + return rc;
> +}
> +
> +int write_mbr_and_gpt_partitions(block_dev_desc_t *dev_desc, void
> *buf) +{
I think that this function is redundant since in part_efi.c is already
defined "write_gpt_table()" function.
It shouldn't be difficult to overlay gpt_header and gpt_entry pointers
on the buf.
> + gpt_header *gpt_h;
> + gpt_entry *gpt_e;
> + int gpt_e_blk_cnt;
> + uint32_t calc_crc32;
> + uint64_t val;
> + lbaint_t lba;
> + int cnt;
> +
> + if (is_valid_gpt_buf(buf, dev_desc->blksz))
> + return -1;
> +
> + /* GPT Header starts at "LBA[1]" in the buffer */
> + gpt_h = buf + 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 plus Primary GPT */
> + lba = 0; /* MBR is always at 0 */
> + cnt = 2; /* MBR + GPT Header (2 blocks) */
> + 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 + 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;
> + }
> +
> + /* recalculate the values for the Backup GPT Header */
> + 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->header_crc32 = 0;
> +
> + calc_crc32 = efi_crc32((const unsigned char *)gpt_h,
> + le32_to_cpu(gpt_h->header_size));
> + gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
> +
> + /* write Backup GPT */
> + lba = le64_to_cpu(gpt_h->last_usable_lba) + 1;
> + 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..fee1c2d 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 buf - buffer which contains the MBR and Primary GPT info
> + * @param blksz - block size (in bytes)
> + *
> + * @return - '0' on success, otherwise error
> + */
> +int is_valid_gpt_buf(void *buf, unsigned long blksz);
> +
> +/**
> + * 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 */
--
Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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