[PATCH v6 2/4] efi: add EFI_DEBUG_IMAGE_INFO_TABLE for debug

[Heinrich Schuchardt]

On 6/17/25 14:08, Ying-Chun Liu (PaulLiu) wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu at linaro.org>
> 
> EFI_DEBUG_IMAGE_INFO_TABLE is used to store EFI_LOADED_IMAGE for
> debug purpose. This commit adds the table to the EFI_CONFIGURATION_TABLE.
> 
> This feature is described in UEFI Spec version 2.10. Section 18.4.
> The implementation ensures support for hardware-assisted debugging and
> provides a standardized mechanism for debuggers to discover and interact
> with system-level debug resources.
> 
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu at linaro.org>
> Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Peter Robinson <pbrobinson at gmail.com>
> Cc: Simon Glass <sjg at chromium.org>
> ---
> V3: Fix the way of installation of configuration table.
> V5: move the code into a separate module.
> ---
>   include/efi_api.h                  | 53 ++++++++++++++++++++++++++++++
>   include/efi_loader.h               |  2 ++
>   lib/efi_loader/efi_debug_support.c |  6 ++++
>   lib/efi_loader/efi_setup.c         | 12 +++++++
>   4 files changed, 73 insertions(+)
> 
> diff --git a/include/efi_api.h b/include/efi_api.h
> index 6c4c1a0cc7b..8da0a350ce3 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -238,6 +238,10 @@ enum efi_reset_type {
>   	EFI_GUID(0xcce33c35, 0x74ac, 0x4087, 0xbc, 0xe7, \
>   		 0x8b, 0x29, 0xb0, 0x2e, 0xeb, 0x27)
>   
> +#define EFI_DEBUG_IMAGE_INFO_TABLE_GUID \
> +	EFI_GUID(0x49152e77, 0x1ada, 0x4764, 0xb7, 0xa2, \
> +		 0x7a, 0xfe, 0xfe, 0xd9, 0x5e, 0x8b)
> +
>   struct efi_conformance_profiles_table {
>   	u16 version;
>   	u16 number_of_profiles;
> @@ -574,6 +578,55 @@ struct efi_loaded_image {
>   	efi_status_t (EFIAPI *unload)(efi_handle_t image_handle);
>   };
>   
> +#define EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS 0x01
> +#define EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED     0x02
> +
> +/**
> + * struct efi_debug_image_info_normal - Store Debug Information for normal
> + * image.
> + * @image_info_type: the type of image info.
> + * @loaded_image_protocol_instance: the pointer to struct efi_loaded_image.
> + * @image_handle: the EFI handle of the image.
> + *
> + * This struct is created by efi_load_image() and store the information
> + * for debugging an normal image.
> + */
> +struct efi_debug_image_info_normal {
> +	u32 image_info_type;
> +	struct efi_loaded_image *loaded_image_protocol_instance;
> +	efi_handle_t image_handle;
> +};
> +
> +/**
> + * union efi_debug_image_info - The union to store a pointer for EFI
> + * DEBUG IMAGE INFO.
> + * @image_info_type: the type of the image_info if it is not a normal image.
> + * @normal_image: The pointer to a normal image.
> + *
> + * This union is for a pointer that can point to the struct of normal_image.
> + * Or it points to an image_info_type.
> + */
> +union efi_debug_image_info {
> +	u32 *image_info_type;
> +	struct efi_debug_image_info_normal *normal_image;
> +};
> +
> +/**
> + * struct efi_debug_image_info_table_header - store the array of
> + * struct efi_debug_image_info.
> + * @update_status: Status to notify this struct is ready to use or not.
> + * @table_size: The number of elements of efi_debug_image_info_table.
> + * @efi_debug_image_info_table: The array of efi_debug_image_info.
> + *
> + * This struct stores the array of efi_debug_image_info. The
> + * number of elements is table_size.
> + */
> +struct efi_debug_image_info_table_header {
> +	volatile u32 update_status;
> +	u32 table_size;
> +	union efi_debug_image_info *efi_debug_image_info_table;
> +};
> +
>   #define EFI_DEVICE_PATH_PROTOCOL_GUID \
>   	EFI_GUID(0x09576e91, 0x6d3f, 0x11d2, \
>   		 0x8e, 0x39, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 8f065244d8e..d0c72d0bc58 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -315,6 +315,8 @@ extern const struct efi_hii_config_routing_protocol efi_hii_config_routing;
>   extern const struct efi_hii_config_access_protocol efi_hii_config_access;
>   extern const struct efi_hii_database_protocol efi_hii_database;
>   extern const struct efi_hii_string_protocol efi_hii_string;
> +/* structure for EFI_DEBUG_SUPPORT_PROTOCOL */
> +extern struct efi_debug_image_info_table_header efi_m_debug_info_table_header;
>   
>   uint16_t *efi_dp_str(struct efi_device_path *dp);
>   
> diff --git a/lib/efi_loader/efi_debug_support.c b/lib/efi_loader/efi_debug_support.c
> index 3794b31c4cd..f2dfcc5e6b2 100644
> --- a/lib/efi_loader/efi_debug_support.c
> +++ b/lib/efi_loader/efi_debug_support.c
> @@ -11,6 +11,12 @@
>   
>   struct efi_system_table_pointer __efi_runtime_data * systab_pointer = NULL;
>   
> +struct efi_debug_image_info_table_header efi_m_debug_info_table_header = {
> +	0,
> +	0,
> +	NULL
> +};
> +
>   /**
>    * efi_initialize_system_table_pointer() - Initialize system table pointer
>    *
> diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
> index 6193b9f6d0c..60f3a7e5fbf 100644
> --- a/lib/efi_loader/efi_setup.c
> +++ b/lib/efi_loader/efi_setup.c
> @@ -18,6 +18,9 @@
>   
>   efi_status_t efi_obj_list_initialized = OBJ_LIST_NOT_INITIALIZED;
>   
> +const efi_guid_t efi_debug_image_info_table_guid =
> +	EFI_DEBUG_IMAGE_INFO_TABLE_GUID;
> +
>   /*
>    * Allow unaligned memory access.
>    *
> @@ -280,10 +283,19 @@ efi_status_t efi_init_obj_list(void)
>   
>   	/* Initialize system table pointer */
>   	if (IS_ENABLED(CONFIG_EFI_DEBUG_SUPPORT)) {
> +		efi_guid_t debug_image_info_table_guid =

This variable shadows the variable defined above.

> +			efi_debug_image_info_table_guid;

This self assignment provides a random value from the stack and not the 
expected GUID.

Please, provide a test in lib/efi_selftest/ verifying that the table is 
installed with the correct GUID.

> +
>   		ret = efi_initialize_system_table_pointer();
>   		if (ret != EFI_SUCCESS) {
>   			goto out;
>   		}
> +
> +		ret = efi_install_configuration_table(&debug_image_info_table_guid,
> +						      &efi_m_debug_info_table_header);
> +		if (ret != EFI_SUCCESS) {
> +			goto out;
> +		}

No braces here. Please, use scripts/checkpatch.pl before resubmitting.

Best regards

Heinrich

>   	}
>   
>   	if (IS_ENABLED(CONFIG_EFI_ECPT)) {