Am 13. Juni 2025 10:57:38 MESZ schrieb Javier Martinez Canillas
<javi...@redhat.com>:
>The UEFI 2.10 specification mentions that this protocol shall be installed
>along with EFI_BLOCK_IO_PROTOCOL. It provides cached partition information
>for MBR and GPT partition types.
U-Boot is targeting the EBBR specifcation which defines a subset of UEFI.
Which application needs this protocol?
Are you planning to add it to the EBBR specification?
Best regards
Heinrich
>
>This patch just implements support for GPT partition types. The legacy MBR
>partition types is only needed for backward compatibility and can be added
>as a follow-up if needed, to make it fully compliant with the EFI spec.
>
>Signed-off-by: Javier Martinez Canillas <javi...@redhat.com>
>---
>
> include/part_efi.h | 20 ++++++++++++++++++++
> lib/efi_loader/efi_disk.c | 38 ++++++++++++++++++++++++++++++++++++--
> 2 files changed, 56 insertions(+), 2 deletions(-)
>
>diff --git a/include/part_efi.h b/include/part_efi.h
>index 59b7895b8a23..fb402df6f13e 100644
>--- a/include/part_efi.h
>+++ b/include/part_efi.h
>@@ -138,4 +138,24 @@ typedef struct _legacy_mbr {
> __le16 signature;
> } __packed legacy_mbr;
>
>+#define EFI_PARTITION_INFO_PROTOCOL_GUID \
>+ EFI_GUID(0x8cf2f62c, 0xbc9b, 0x4821, 0x80, \
>+ 0x8d, 0xec, 0x9e, 0xc4, 0x21, 0xa1, 0xa0)
>+
>+#define EFI_PARTITION_INFO_PROTOCOL_REVISION 0x0001000
>+#define PARTITION_TYPE_OTHER 0x00
>+#define PARTITION_TYPE_MBR 0x01
>+#define PARTITION_TYPE_GPT 0x02
>+
>+struct efi_partition_info {
>+ u32 revision;
>+ u32 type;
>+ u8 system;
>+ u8 reserved[7];
>+ union {
>+ struct partition mbr;
>+ gpt_entry gpt;
>+ } info;
>+} __packed;
>+
> #endif /* _DISK_PART_EFI_H */
>diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
>index 47b583cc5e12..ba41b77b9d1c 100644
>--- a/lib/efi_loader/efi_disk.c
>+++ b/lib/efi_loader/efi_disk.c
>@@ -26,6 +26,7 @@ struct efi_system_partition efi_system_partition = {
>
> const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
> const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID;
>+const efi_guid_t efi_partition_info_guid = EFI_PARTITION_INFO_PROTOCOL_GUID;
>
> /**
> * struct efi_disk_obj - EFI disk object
>@@ -35,6 +36,7 @@ const efi_guid_t efi_system_partition_guid =
>PARTITION_SYSTEM_GUID;
> * @media: block I/O media information
> * @dp: device path to the block device
> * @volume: simple file system protocol of the partition
>+ * @info: EFI partition info protocol interface
> */
> struct efi_disk_obj {
> struct efi_object header;
>@@ -42,6 +44,7 @@ struct efi_disk_obj {
> struct efi_block_io_media media;
> struct efi_device_path *dp;
> struct efi_simple_file_system_protocol *volume;
>+ struct efi_partition_info info;
> };
>
> /**
>@@ -426,6 +429,7 @@ static efi_status_t efi_disk_add_dev(
> /* Fill in object data */
> if (part_info) {
> struct efi_device_path *node = efi_dp_part_node(desc, part);
>+ struct efi_partition_info *info = &diskobj->info;
> struct efi_handler *handler;
> void *protocol_interface;
>
>@@ -454,18 +458,47 @@ static efi_status_t efi_disk_add_dev(
> goto error;
> }
>
>+ info->revision = EFI_PARTITION_INFO_PROTOCOL_REVISION;
>+
>+ switch (desc->part_type) {
>+ case PART_TYPE_EFI:
>+ info->type = PARTITION_TYPE_GPT;
>+ ret = part_get_gpt_pte(desc, part, &info->info.gpt);
>+ if (ret) {
>+ log_debug("get PTE for part %d failed %ld\n",
>+ part, ret);
>+ goto error;
>+ }
>+
>+ break;
>+ case PART_TYPE_DOS:
>+ info->type = PARTITION_TYPE_MBR;
>+
>+ /* TODO: implement support for MBR partition types */
>+ log_debug("EFI_PARTITION_INFO_PROTOCOL doesn't support
>MBR\n");
>+
>+ break;
>+ default:
>+ info->type = PARTITION_TYPE_OTHER;
>+
>+ break;
>+ }
>+
> diskobj->dp = efi_dp_append_node(dp_parent, node);
> efi_free_pool(node);
> diskobj->media.last_block = part_info->size - 1;
>- if (part_info->bootable & PART_EFI_SYSTEM_PARTITION)
>+ if (part_info->bootable & PART_EFI_SYSTEM_PARTITION) {
> esp_guid = &efi_system_partition_guid;
>+ info->system = 1;
>+ }
>+
> } else {
> diskobj->dp = efi_dp_from_part(desc, part);
> diskobj->media.last_block = desc->lba - 1;
> }
>
> /*
>- * Install the device path and the block IO protocol.
>+ * Install the device path, the block IO and partition info protocols.
> *
> * InstallMultipleProtocolInterfaces() checks if the device path is
> * already installed on an other handle and returns EFI_ALREADY_STARTED
>@@ -476,6 +509,7 @@ static efi_status_t efi_disk_add_dev(
> &handle,
> &efi_guid_device_path, diskobj->dp,
> &efi_block_io_guid, &diskobj->ops,
>+ &efi_partition_info_guid,
>&diskobj->info,
> /*
> * esp_guid must be last entry as it
> * can be NULL. Its interface is NULL.
