[U-Boot] [PATCH v1 03/15] part: extract MBR signature from partitions

[Alexander Graf]

On 10.08.17 20:29, Rob Clark wrote:
> From: Peter Jones <pjones at redhat.com>
> 
> EFI client programs need the signature information from the partition
> table to determine the disk a partition is on, so we need to fill that
> in here.
> 
> Signed-off-by: Peter Jones <pjones at redhat.com>
> [separated from efi_loader part, and fixed build-errors for non-
>   CONFIG_EFI_PARTITION case]
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
>   disk/part_dos.c    | 12 +++++++++---
>   disk/part_efi.c    | 20 ++++++++++++++++++++
>   include/blk.h      | 15 +++++++++++++++
>   include/efi.h      |  4 ++++
>   include/part.h     |  3 ++-
>   include/part_efi.h |  4 ----
>   6 files changed, 50 insertions(+), 8 deletions(-)
> 
> diff --git a/disk/part_dos.c b/disk/part_dos.c
> index 7ede15ec26..850a538e83 100644
> --- a/disk/part_dos.c
> +++ b/disk/part_dos.c
> @@ -89,14 +89,20 @@ static int test_block_type(unsigned char *buffer)
>   
>   static int part_test_dos(struct blk_desc *dev_desc)
>   {
> -	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
> +	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, dev_desc->blksz);
>   
> -	if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
> +	if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1)
>   		return -1;
>   
> -	if (test_block_type(buffer) != DOS_MBR)
> +	if (test_block_type((unsigned char *)mbr) != DOS_MBR)
>   		return -1;
>   
> +	if (dev_desc->sig_type == SIG_TYPE_NONE &&
> +	    mbr->unique_mbr_signature != 0) {
> +		dev_desc->sig_type = SIG_TYPE_MBR;
> +		dev_desc->mbr_sig = mbr->unique_mbr_signature;
> +	}
> +
>   	return 0;
>   }
>   
> diff --git a/disk/part_efi.c b/disk/part_efi.c
> index 1b7ba27947..71e4188455 100644
> --- a/disk/part_efi.c
> +++ b/disk/part_efi.c
> @@ -871,11 +871,19 @@ static int is_pmbr_valid(legacy_mbr * mbr)
>   static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
>   			gpt_header *pgpt_head, gpt_entry **pgpt_pte)
>   {
> +	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, dev_desc->blksz);
> +
>   	if (!dev_desc || !pgpt_head) {
>   		printf("%s: Invalid Argument(s)\n", __func__);
>   		return 0;
>   	}
>   
> +	/* Read MBR Header from device */
> +	if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1) {
> +		printf("*** ERROR: Can't read MBR header ***\n");
> +		return 0;
> +	}
> +
>   	/* Read GPT Header from device */
>   	if (blk_dread(dev_desc, (lbaint_t)lba, 1, pgpt_head) != 1) {
>   		printf("*** ERROR: Can't read GPT header ***\n");
> @@ -885,6 +893,18 @@ static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
>   	if (validate_gpt_header(pgpt_head, (lbaint_t)lba, dev_desc->lba))
>   		return 0;
>   
> +	if (dev_desc->sig_type == SIG_TYPE_NONE) {
> +		efi_guid_t empty = {};
> +		if (memcmp(&pgpt_head->disk_guid, &empty, sizeof(empty))) {
> +			dev_desc->sig_type = SIG_TYPE_GUID;
> +			memcpy(&dev_desc->guid_sig, &pgpt_head->disk_guid,
> +			      sizeof(empty));
> +		} else if (mbr->unique_mbr_signature != 0) {
> +			dev_desc->sig_type = SIG_TYPE_MBR;
> +			dev_desc->mbr_sig = mbr->unique_mbr_signature;
> +		}
> +	}
> +
>   	/* Read and allocate Partition Table Entries */
>   	*pgpt_pte = alloc_read_gpt_entries(dev_desc, pgpt_head);
>   	if (*pgpt_pte == NULL) {
> diff --git a/include/blk.h b/include/blk.h
> index ef29a07ee2..3a5e04c00d 100644
> --- a/include/blk.h
> +++ b/include/blk.h
> @@ -8,6 +8,8 @@
>   #ifndef BLK_H
>   #define BLK_H
>   
> +#include <efi.h>
> +
>   #ifdef CONFIG_SYS_64BIT_LBA
>   typedef uint64_t lbaint_t;
>   #define LBAFlength "ll"
> @@ -35,6 +37,14 @@ enum if_type {
>   	IF_TYPE_COUNT,			/* Number of interface types */
>   };
>   
> +enum sig_type {
> +	SIG_TYPE_NONE,
> +	SIG_TYPE_MBR,
> +	SIG_TYPE_GUID,
> +
> +	SIG_TYPE_COUNT			/* Number of signature types */
> +};
> +
>   /*
>    * With driver model (CONFIG_BLK) this is uclass platform data, accessible
>    * with dev_get_uclass_platdata(dev)
> @@ -62,6 +72,11 @@ struct blk_desc {
>   	char		vendor[40+1];	/* IDE model, SCSI Vendor */
>   	char		product[20+1];	/* IDE Serial no, SCSI product */
>   	char		revision[8+1];	/* firmware revision */
> +	enum sig_type	sig_type;	/* Partition table signature type */
> +	union {
> +		uint32_t mbr_sig;	/* MBR integer signature */
> +		efi_guid_t guid_sig;	/* GPT GUID Signature */
> +	};
>   #ifdef CONFIG_BLK
>   	/*
>   	 * For now we have a few functions which take struct blk_desc as a
> diff --git a/include/efi.h b/include/efi.h
> index 02b78b31b1..87b0b43f20 100644
> --- a/include/efi.h
> +++ b/include/efi.h
> @@ -28,6 +28,10 @@
>   
>   struct efi_device_path;
>   
> +typedef struct {
> +	u8 b[16];
> +} efi_guid_t;
> +
>   #define EFI_BITS_PER_LONG	BITS_PER_LONG
>   
>   /*
> diff --git a/include/part.h b/include/part.h
> index 83bce05a43..ac5ee895e9 100644
> --- a/include/part.h
> +++ b/include/part.h
> @@ -259,8 +259,9 @@ struct part_driver {
>   #define U_BOOT_PART_TYPE(__name)					\
>   	ll_entry_declare(struct part_driver, __name, part_driver)
>   
> -#if CONFIG_IS_ENABLED(EFI_PARTITION)
>   #include <part_efi.h>
> +
> +#if CONFIG_IS_ENABLED(EFI_PARTITION)

Is this change still necessary despite the move of efi_guid_t?

>   /* disk/part_efi.c */
>   /**
>    * write_gpt_table() - Write the GUID Partition Table to disk
> diff --git a/include/part_efi.h b/include/part_efi.h
> index 317c044795..31e6bc6e14 100644
> --- a/include/part_efi.h
> +++ b/include/part_efi.h
> @@ -58,10 +58,6 @@
>   /* linux/include/efi.h */
>   typedef u16 efi_char16_t;
>   
> -typedef struct {
> -	u8 b[16];
> -} efi_guid_t;

Moving the efi_guid_t definition would be good to have as a separate 
patch for bisection purposes.


Alex