[PATCH v13 5/9] bootmenu: add removable media entries

Ilias Apalodimas ilias.apalodimas at linaro.org
Wed Aug 24 15:25:08 CEST 2022


Hi Kojima-san

On Wed, Aug 24, 2022 at 03:37:36PM +0900, Masahisa Kojima wrote:
> UEFI specification requires booting from removal media using
> a architecture-specific default image name such as BOOTAA64.EFI.
> This commit adds the removable media entries into bootmenu,
> so that user can select the removable media and boot with
> default image.
> 
> The bootmenu automatically enumerates the possible bootable
> media devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL,
> add it as new UEFI boot option(BOOT####) and update BootOrder
> variable. This automatically generated UEFI boot option
> has the dedicated guid in the optional_data to distinguish it from
> the UEFI boot option user adds manually. This optional_data is
> removed when the efi bootmgr loads the selected UEFI boot option.
> 
> This commit also provides the BOOT#### variable maintenance feature.
> Depending on the system hardware setup, some devices
> may not exist at a later system boot, so bootmenu checks the
> available device in each bootmenu invocation and automatically
> removes the BOOT#### variable corrensponding to the non-existent
> media device.
> 

Maybe I am doing something wrong here and this has been discussed in the
past, but here's what I get by testing this.

- The automatic scanning of boot options seems to be happening only when 
  "Change boot order" menu is selected.  Isn't it better to do it on
  eficonfig startup ?
- Although I can see a variable Boot0000 which holds the device path of the
  virtio disk that has the BOOTAA64.EFI file, I can't see that option in
  the edit/delete menus
 
Thanks
/Ilias
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
> Changes in v13:
> - remove BootOrder variable dependency
> 
> Changes in v12:
> - move generate_media_device_boot_option into cmd/eficonfig.c and expose it
> - remove unnecessary include file
> 
> Changes in v11:
> - update delete_boot_option() parameter
> 
> Changes in v10:
> - add function comment
> - devname dynamic allocation removes, allocate in stack
> - delete BOOT#### when updating BootOrder fails
> 
> Changes in v9:
> - update efi_disk_get_device_name() parameter to pass efi_handle_t
> - add function comment
> 
> Changes in v8:
> - function and structure prefix is changed to "eficonfig"
> 
> Changes in v7:
> - rename prepare_media_device_entry() to generate_media_device_boot_option()
> 
> Changes in v6:
> - optional_data size is changed to 16bytes
> - check the load option size before comparison
> - remove guid included in optional_data of auto generated
>   entry when loading
> 
> Changes in v5:
> - Return EFI_SUCCESS if there is no BootOrder defined
> - correctly handle the case if no removable device found
> - use guid to identify the automatically generated entry by bootmenu
> 
>  cmd/bootmenu.c               |  22 +++-
>  cmd/eficonfig.c              | 209 +++++++++++++++++++++++++++++++++++
>  include/efi_config.h         |   1 +
>  include/efi_loader.h         |  16 +++
>  lib/efi_loader/efi_bootmgr.c |   4 +
>  5 files changed, 246 insertions(+), 6 deletions(-)
> 
> diff --git a/cmd/bootmenu.c b/cmd/bootmenu.c
> index 704d36debe..3340be1632 100644
> --- a/cmd/bootmenu.c
> +++ b/cmd/bootmenu.c
> @@ -7,7 +7,7 @@
>  #include <common.h>
>  #include <command.h>
>  #include <ansi.h>
> -#include <efi_loader.h>
> +#include <efi_config.h>
>  #include <efi_variable.h>
>  #include <env.h>
>  #include <log.h>
> @@ -220,7 +220,7 @@ static int prepare_bootmenu_entry(struct bootmenu_data *menu,
>  	return 1;
>  }
>  
> -#if (CONFIG_IS_ENABLED(CMD_BOOTEFI_BOOTMGR))
> +#if (CONFIG_IS_ENABLED(CMD_BOOTEFI_BOOTMGR)) && (CONFIG_IS_ENABLED(CMD_EFICONFIG))
>  /**
>   * prepare_uefi_bootorder_entry() - generate the uefi bootmenu entries
>   *
> @@ -340,11 +340,21 @@ static struct bootmenu_data *bootmenu_create(int delay)
>  	if (ret < 0)
>  		goto cleanup;
>  
> -#if (CONFIG_IS_ENABLED(CMD_BOOTEFI_BOOTMGR))
> +#if (CONFIG_IS_ENABLED(CMD_BOOTEFI_BOOTMGR)) && (CONFIG_IS_ENABLED(CMD_EFICONFIG))
>  	if (i < MAX_COUNT - 1) {
> -			ret = prepare_uefi_bootorder_entry(menu, &iter, &i);
> -			if (ret < 0 && ret != -ENOENT)
> -				goto cleanup;
> +		efi_status_t efi_ret;
> +
> +		/*
> +		 * UEFI specification requires booting from removal media using
> +		 * a architecture-specific default image name such as BOOTAA64.EFI.
> +		 */
> +		efi_ret = eficonfig_generate_media_device_boot_option();
> +		if (efi_ret != EFI_SUCCESS && efi_ret != EFI_NOT_FOUND)
> +			goto cleanup;
> +
> +		ret = prepare_uefi_bootorder_entry(menu, &iter, &i);
> +		if (ret < 0 && ret != -ENOENT)
> +			goto cleanup;
>  	}
>  #endif
>  
> diff --git a/cmd/eficonfig.c b/cmd/eficonfig.c
> index 537f3f2bbc..92171c4894 100644
> --- a/cmd/eficonfig.c
> +++ b/cmd/eficonfig.c
> @@ -1786,6 +1786,215 @@ static efi_status_t eficonfig_process_delete_boot_option(void *data)
>  	return ret;
>  }
>  
> +/**
> + * eficonfig_enumerate_boot_option() - enumerate the possible bootable media
> + *
> + * @opt:		pointer to the media boot option structure
> + * @volume_handles:	pointer to the efi handles
> + * @count:		number of efi handle
> + * Return:		status code
> + */
> +efi_status_t eficonfig_enumerate_boot_option(struct eficonfig_media_boot_option *opt,
> +					     efi_handle_t *volume_handles, efi_status_t count)
> +{
> +	u32 i;
> +	struct efi_handler *handler;
> +	efi_status_t ret = EFI_SUCCESS;
> +
> +	for (i = 0; i < count; i++) {
> +		u16 *p;
> +		u16 dev_name[BOOTMENU_DEVICE_NAME_MAX];
> +		char *optional_data;
> +		struct efi_load_option lo;
> +		char buf[BOOTMENU_DEVICE_NAME_MAX];
> +		struct efi_device_path *device_path;
> +
> +		ret = efi_search_protocol(volume_handles[i], &efi_guid_device_path, &handler);
> +		if (ret != EFI_SUCCESS)
> +			continue;
> +		ret = efi_protocol_open(handler, (void **)&device_path,
> +					efi_root, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
> +		if (ret != EFI_SUCCESS)
> +			continue;
> +
> +		ret = efi_disk_get_device_name(volume_handles[i], buf, BOOTMENU_DEVICE_NAME_MAX);
> +		if (ret != EFI_SUCCESS)
> +			continue;
> +
> +		p = dev_name;
> +		utf8_utf16_strncpy(&p, buf, strlen(buf));
> +
> +		lo.label = dev_name;
> +		lo.attributes = LOAD_OPTION_ACTIVE;
> +		lo.file_path = device_path;
> +		lo.file_path_length = efi_dp_size(device_path) + sizeof(END);
> +		/*
> +		 * Set the dedicated guid to optional_data, it is used to identify
> +		 * the boot option that automatically generated by the bootmenu.
> +		 * efi_serialize_load_option() expects optional_data is null-terminated
> +		 * utf8 string, so set the "1234567" string to allocate enough space
> +		 * to store guid, instead of realloc the load_option.
> +		 */
> +		lo.optional_data = "1234567";
> +		opt[i].size = efi_serialize_load_option(&lo, (u8 **)&opt[i].lo);
> +		if (!opt[i].size) {
> +			ret = EFI_OUT_OF_RESOURCES;
> +			free(dev_name);
> +			goto out;
> +		}
> +		/* set the guid */
> +		optional_data = (char *)opt[i].lo + (opt[i].size - u16_strsize(u"1234567"));
> +		memcpy(optional_data, &efi_guid_bootmenu_auto_generated, sizeof(efi_guid_t));
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +/**
> + * eficonfig_delete_invalid_boot_option() - delete non-existing boot option
> + *
> + * @opt:		pointer to the media boot option structure
> + * @count:		number of media boot option structure
> + * Return:		status code
> + */
> +efi_status_t eficonfig_delete_invalid_boot_option(struct eficonfig_media_boot_option *opt,
> +						  efi_status_t count)
> +{
> +	u32 i, j;
> +	efi_uintn_t size;
> +	efi_status_t ret;
> +	void *load_option;
> +	struct efi_load_option lo;
> +	u16 varname[] = u"Boot####";
> +
> +	for (i = 0; i <= 0xFFFF; i++) {
> +		efi_uintn_t tmp;
> +
> +		efi_create_indexed_name(varname, sizeof(varname), "Boot", i);
> +		load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
> +		if (!load_option)
> +			continue;
> +
> +		tmp = size;
> +		ret = efi_deserialize_load_option(&lo, load_option, &size);
> +		if (ret != EFI_SUCCESS)
> +			goto next;
> +
> +		if (size >= sizeof(efi_guid_bootmenu_auto_generated)) {
> +			if (guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated) == 0) {
> +				for (j = 0; j < count; j++) {
> +					if (opt[j].size == tmp &&
> +					    memcmp(opt[j].lo, load_option, tmp) == 0) {
> +						opt[j].exist = true;
> +						break;
> +					}
> +				}
> +
> +				if (j == count) {
> +					ret = delete_boot_option(i);
> +					if (ret != EFI_SUCCESS) {
> +						free(load_option);
> +						goto out;
> +					}
> +				}
> +			}
> +		}
> +next:
> +		free(load_option);
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +/**
> + * eficonfig_generate_media_device_boot_option() - generate the media device boot option
> + *
> + * This function enumerates all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
> + * and generate the bootmenu entries.
> + * This function also provide the BOOT#### variable maintenance for
> + * the media device entries.
> + *   - Automatically create the BOOT#### variable for the newly detected device,
> + *     this BOOT#### variable is distinguished by the special GUID
> + *     stored in the EFI_LOAD_OPTION.optional_data
> + *   - If the device is not attached to the system, the associated BOOT#### variable
> + *     is automatically deleted.
> + *
> + * Return:	status code
> + */
> +efi_status_t eficonfig_generate_media_device_boot_option(void)
> +{
> +	u32 i;
> +	efi_status_t ret;
> +	efi_uintn_t count;
> +	efi_handle_t *volume_handles = NULL;
> +	struct eficonfig_media_boot_option *opt = NULL;
> +
> +	ret = efi_locate_handle_buffer_int(BY_PROTOCOL, &efi_simple_file_system_protocol_guid,
> +					   NULL, &count, (efi_handle_t **)&volume_handles);
> +	if (ret != EFI_SUCCESS)
> +		return ret;
> +
> +	opt = calloc(count, sizeof(struct eficonfig_media_boot_option));
> +	if (!opt)
> +		goto out;
> +
> +	/* enumerate all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL */
> +	ret = eficonfig_enumerate_boot_option(opt, volume_handles, count);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	/*
> +	 * System hardware configuration may vary depending on the user setup.
> +	 * The boot option is automatically added by the bootmenu.
> +	 * If the device is not attached to the system, the boot option needs
> +	 * to be deleted.
> +	 */
> +	ret = eficonfig_delete_invalid_boot_option(opt, count);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	/* add non-existent boot option */
> +	for (i = 0; i < count; i++) {
> +		u32 boot_index;
> +		u16 var_name[9];
> +
> +		if (!opt[i].exist) {
> +			ret = eficonfig_get_unused_bootoption(var_name, sizeof(var_name),
> +							      &boot_index);
> +			if (ret != EFI_SUCCESS)
> +				goto out;
> +
> +			ret = efi_set_variable_int(var_name, &efi_global_variable_guid,
> +						   EFI_VARIABLE_NON_VOLATILE |
> +						   EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +						   EFI_VARIABLE_RUNTIME_ACCESS,
> +						   opt[i].size, opt[i].lo, false);
> +			if (ret != EFI_SUCCESS)
> +				goto out;
> +
> +			ret = eficonfig_append_bootorder(boot_index);
> +			if (ret != EFI_SUCCESS) {
> +				efi_set_variable_int(var_name, &efi_global_variable_guid,
> +						     0, 0, NULL, false);
> +				goto out;
> +			}
> +		}
> +	}
> +
> +out:
> +	if (opt) {
> +		for (i = 0; i < count; i++)
> +			free(opt[i].lo);
> +	}
> +	free(opt);
> +	efi_free_pool(volume_handles);
> +
> +	return ret;
> +}
> +
> +
>  /**
>   * eficonfig_init() - do required initialization for eficonfig command
>   *
> diff --git a/include/efi_config.h b/include/efi_config.h
> index 974d8ce1ee..55ace89e4a 100644
> --- a/include/efi_config.h
> +++ b/include/efi_config.h
> @@ -92,5 +92,6 @@ efi_status_t eficonfig_select_file_handler(void *data);
>  efi_status_t eficonfig_get_unused_bootoption(u16 *buf,
>  					     efi_uintn_t buf_size, u32 *index);
>  efi_status_t eficonfig_append_bootorder(u16 index);
> +efi_status_t eficonfig_generate_media_device_boot_option(void);
>  
>  #endif
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 4461f721e0..6b63ae8dde 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -953,6 +953,22 @@ struct efi_signature_store {
>  struct x509_certificate;
>  struct pkcs7_message;
>  
> +/**
> + * struct eficonfig_media_boot_option - boot option for (removable) media device
> + *
> + * This structure is used to enumerate possible boot option
> + *
> + * @lo:		Serialized load option data
> + * @size:	Size of serialized load option data
> + * @exist:	Flag to indicate the load option already exists
> + *		in Non-volatile load option
> + */
> +struct eficonfig_media_boot_option {
> +	void *lo;
> +	efi_uintn_t size;
> +	bool exist;
> +};
> +
>  bool efi_hash_regions(struct image_region *regs, int count,
>  		      void **hash, const char *hash_algo, int *len);
>  bool efi_signature_lookup_digest(struct efi_image_regions *regs,
> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> index ede9116b3c..4b24b41047 100644
> --- a/lib/efi_loader/efi_bootmgr.c
> +++ b/lib/efi_loader/efi_bootmgr.c
> @@ -246,6 +246,10 @@ static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
>  	}
>  
>  	/* Set load options */
> +	if (size >= sizeof(efi_guid_t) &&
> +	    !guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated))
> +		size = 0;
> +
>  	if (size) {
>  		*load_options = malloc(size);
>  		if (!*load_options) {
> -- 
> 2.17.1
> 


More information about the U-Boot mailing list