On Thu, 3 Jul 2025 at 09:28, Ying-Chun Liu (PaulLiu) <paul...@debian.org> wrote:
>
> From: "Ying-Chun Liu (PaulLiu)" <paul....@linaro.org>
>
> This commit adds the functionality of generate EFI_DEBUG_IMAGE_INFO
> while loading the image.
>
> This feature is described in UEFI Spec 2.10. Section 18.4.3.
> The implementation ensures support for hardware-assisted debugging and
> provides a standardized mechanism for debuggers to discover the load
> address of an EFI application.
>
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul....@linaro.org>
> Tested-by: Heinrich Schuchardt <xypron.g...@gmx.de>
> Cc: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> Cc: Peter Robinson <pbrobin...@gmail.com>
> Cc: Simon Glass <s...@chromium.org>
> ---
Acked-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> V2: use Kconfig options to turn on/off this feature.
> V3: Use efi_realloc to realloc the tables. Move tables to boot time.
> V4: Use new efi_realloc().
> V5: Fix function comments and move the code into a separate module.
> V6: refine the code. Handling the error of efi_allocate_pool.
> V7: Use memmove instead of memcpy. Fix syntax warnings.
> ---
> include/efi_api.h | 2 +
> include/efi_loader.h | 5 ++
> lib/efi_loader/efi_boottime.c | 7 ++
> lib/efi_loader/efi_debug_support.c | 137 +++++++++++++++++++++++++++++
> 4 files changed, 151 insertions(+)
>
> diff --git a/include/efi_api.h b/include/efi_api.h
> index 8da0a350ce3..77a05f752e5 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -581,6 +581,8 @@ struct efi_loaded_image {
> #define EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS 0x01
> #define EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED 0x02
>
> +#define EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL 0x01
> +
> /**
> * struct efi_debug_image_info_normal - Store Debug Information for normal
> * image.
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 13ca2ec9a4e..22440b842e3 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -650,6 +650,11 @@ efi_status_t efi_root_node_register(void);
> efi_status_t efi_initialize_system_table(void);
> /* Called by bootefi to initialize debug */
> efi_status_t efi_initialize_system_table_pointer(void);
> +/* Called by efi_load_image for register debug info */
> +efi_status_t efi_core_new_debug_image_info_entry(u32 image_info_type,
> + struct efi_loaded_image
> *loaded_image,
> + efi_handle_t image_handle);
> +void efi_core_remove_debug_image_info_entry(efi_handle_t image_handle);
> /* efi_runtime_detach() - detach unimplemented runtime functions */
> void efi_runtime_detach(void);
> /* efi_convert_pointer() - convert pointer to virtual address */
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index dbebb37dc04..8c83040ac48 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -2129,6 +2129,11 @@ efi_status_t EFIAPI efi_load_image(bool boot_policy,
> *image_handle = NULL;
> free(info);
> }
> +
> + if (IS_ENABLED(CONFIG_EFI_DEBUG_SUPPORT) && *image_handle)
> +
> efi_core_new_debug_image_info_entry(EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL,
> + info,
> + *image_handle);
> error:
> return EFI_EXIT(ret);
> }
> @@ -3359,6 +3364,8 @@ efi_status_t EFIAPI efi_unload_image(efi_handle_t
> image_handle)
> ret = EFI_INVALID_PARAMETER;
> goto out;
> }
> + if (IS_ENABLED(CONFIG_EFI_DEBUG_SUPPORT))
> + efi_core_remove_debug_image_info_entry(image_handle);
> switch (efiobj->type) {
> case EFI_OBJECT_TYPE_STARTED_IMAGE:
> /* Call the unload function */
> diff --git a/lib/efi_loader/efi_debug_support.c
> b/lib/efi_loader/efi_debug_support.c
> index 5401488602e..17f506a70e7 100644
> --- a/lib/efi_loader/efi_debug_support.c
> +++ b/lib/efi_loader/efi_debug_support.c
> @@ -17,6 +17,13 @@ struct efi_debug_image_info_table_header
> efi_m_debug_info_table_header = {
> NULL
> };
>
> +/* efi_m_max_table_entries is the maximum entries allocated for
> + * the efi_m_debug_info_table_header.efi_debug_image_info_table.
> + */
> +static u32 efi_m_max_table_entries;
> +
> +#define EFI_DEBUG_TABLE_ENTRY_SIZE (sizeof(union efi_debug_image_info *))
> +
> /**
> * efi_initialize_system_table_pointer() - Initialize system table pointer
> *
> @@ -44,3 +51,133 @@ efi_status_t efi_initialize_system_table_pointer(void)
>
> return EFI_SUCCESS;
> }
> +
> +/**
> + * efi_core_new_debug_image_info_entry() - Add a new efi_loaded_image
> structure to the
> + * efi_debug_image_info table.
> + *
> + * @image_info_type: type of debug image information
> + * @loaded_image: pointer to the loaded image protocol for the image
> + * being loaded
> + * @image_handle: image handle for the image being loaded
> + *
> + * Re-Allocates the table if it's not large enough to accommodate another
> + * entry.
> + *
> + * Return: status code
> + **/
> +efi_status_t efi_core_new_debug_image_info_entry(u32 image_info_type,
> + struct efi_loaded_image
> *loaded_image,
> + efi_handle_t image_handle)
> +{
> + union efi_debug_image_info **table;
> + u32 index;
> + u32 table_size;
> + efi_status_t ret;
> +
> + /* Set the flag indicating that we're in the process of updating
> + * the table.
> + */
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +
> + table = &efi_m_debug_info_table_header.efi_debug_image_info_table;
> +
> + if (efi_m_debug_info_table_header.table_size >=
> efi_m_max_table_entries) {
> + /* table is full, re-allocate the buffer increasing the size
> + * by 4 KiB.
> + */
> + table_size = efi_m_max_table_entries *
> EFI_DEBUG_TABLE_ENTRY_SIZE;
> +
> + ret = efi_realloc((void **)table, table_size + EFI_PAGE_SIZE);
> +
> + if (ret != EFI_SUCCESS) {
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> + return ret;
> + }
> +
> + /* Enlarge the max table entries and set the first empty
> + * entry index to be the original max table entries.
> + */
> + efi_m_max_table_entries +=
> + EFI_PAGE_SIZE / EFI_DEBUG_TABLE_ENTRY_SIZE;
> + }
> +
> + /* We always put the next entry at the end of the currently consumed
> + * table (i.e. first free entry)
> + */
> + index = efi_m_debug_info_table_header.table_size;
> +
> + /* Allocate data for new entry. */
> + ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
> + sizeof(union efi_debug_image_info),
> + (void **)(&(*table)[index].normal_image));
> + if (ret == EFI_SUCCESS && (*table)[index].normal_image) {
> + /* Update the entry. */
> + (*table)[index].normal_image->image_info_type =
> image_info_type;
> + (*table)[index].normal_image->loaded_image_protocol_instance =
> + loaded_image;
> + (*table)[index].normal_image->image_handle = image_handle;
> +
> + /* Increase the number of EFI_DEBUG_IMAGE_INFO elements and
> + * set the efi_m_debug_info_table_header in modified status.
> + */
> + efi_m_debug_info_table_header.table_size++;
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;
> + } else {
> + log_err("Adding new efi_debug_image_info failed\n");
> + return ret;
> + }
> +
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +
> + return EFI_SUCCESS;
> +}
> +
> +/**
> + * efi_core_remove_debug_image_info_entry() - Remove an efi_debug_image_info
> entry.
> + *
> + * @image_handle: image handle for the image being removed
> + **/
> +void efi_core_remove_debug_image_info_entry(efi_handle_t image_handle)
> +{
> + union efi_debug_image_info *table;
> + u32 index;
> +
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +
> + table = efi_m_debug_info_table_header.efi_debug_image_info_table;
> +
> + for (index = 0; index < efi_m_max_table_entries; index++) {
> + if (table[index].normal_image &&
> + table[index].normal_image->image_handle == image_handle) {
> + /* Found a match. Free up the table entry.
> + * Move the tail of the table one slot to the front.
> + */
> + efi_free_pool(table[index].normal_image);
> +
> + memmove(&table[index],
> + &table[index + 1],
> + (efi_m_debug_info_table_header.table_size -
> + index - 1) * EFI_DEBUG_TABLE_ENTRY_SIZE);
> +
> + /* Decrease the number of EFI_DEBUG_IMAGE_INFO
> + * elements and set the efi_m_debug_info_table_header
> + * in modified status.
> + */
> + efi_m_debug_info_table_header.table_size--;
> +
> table[efi_m_debug_info_table_header.table_size].normal_image =
> + NULL;
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;
> + break;
> + }
> + }
> +
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +}
> --
> 2.39.5
>
