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author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2022-04-28 17:09:39 +0900 |
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committer | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2022-05-03 21:39:22 +0200 |
commit | 4e65ca00f3a30791752529fe9ffe8c02da104c62 (patch) | |
tree | a6b7a708e4b173cccef316f55c15fc73a2c24e67 /lib | |
parent | d8465ffc019a742ae6c8770179f359317c5f101a (diff) | |
download | u-boot-4e65ca00f3a30791752529fe9ffe8c02da104c62.zip u-boot-4e65ca00f3a30791752529fe9ffe8c02da104c62.tar.gz u-boot-4e65ca00f3a30791752529fe9ffe8c02da104c62.tar.bz2 |
efi_loader: bootmgr: add booting from removable media
Under the current implementation, booting from removable media using
a architecture-specific default image name, say BOOTAA64.EFI, is
supported only in distro_bootcmd script. See the commit 74522c898b35
("efi_loader: Add distro boot script for removable media").
This is, however, half-baked implementation because
1) UEFI specification requires this feature to be implemented as part
of Boot Manager's responsibility:
3 - Boot Manager
3.5.1 Boot via the Simple File Protocol
When booting via the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL, the FilePath will
start with a device path that points to the device that implements the
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL or the EFI_BLOCK_IO_PROTOCOL. The next
part of the FilePath may point to the file name, including
subdirectories, which contain the bootable image. If the file name is
a null device path, the file name must be generated from the rules
defined below.
...
3.5.1.1 Removable Media Boot Behavior
To generate a file name when none is present in the FilePath, the
firmware must append a default file name in the form
\EFI\BOOT\BOOT{machine type short-name}.EFI ...
2) So (1) entails the hehavior that the user's preference of boot media
order should be determined by Boot#### and BootOrder variables.
With this patch, the semantics mentioned above is fully implemented.
For example, if you want to boot the system from USB and SCSI in this
order,
* define Boot0001 which contains only a device path to the USB device
(without any file path/name)
* define Boot0002 which contains only a device path to the SCSI device,
and
* set BootOrder to Boot0001:Boot0002
To avoid build error for sandbox, default file name "BOOTSANDBOX.efi"
is defined even if it is out of scope of UEFI specification.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
On sandbox use binary name corresponding to host architecture.
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/efi_loader/efi_bootmgr.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c index 52bea4d..631a25d 100644 --- a/lib/efi_loader/efi_bootmgr.c +++ b/lib/efi_loader/efi_bootmgr.c @@ -11,6 +11,7 @@ #include <charset.h> #include <log.h> #include <malloc.h> +#include <efi_default_filename.h> #include <efi_loader.h> #include <efi_variable.h> #include <asm/unaligned.h> @@ -31,6 +32,51 @@ static const struct efi_runtime_services *rs; */ /** + * expand_media_path() - expand a device path for default file name + * @device_path: device path to check against + * + * If @device_path is a media or disk partition which houses a file + * system, this function returns a full device path which contains + * an architecture-specific default file name for removable media. + * + * Return: a newly allocated device path + */ +static +struct efi_device_path *expand_media_path(struct efi_device_path *device_path) +{ + struct efi_device_path *dp, *full_path; + efi_handle_t handle; + efi_status_t ret; + + if (!device_path) + return NULL; + + /* + * If device_path is a (removable) media or partition which provides + * simple file system protocol, append a default file name to support + * booting from removable media. + */ + dp = device_path; + ret = EFI_CALL(efi_locate_device_path( + &efi_simple_file_system_protocol_guid, + &dp, &handle)); + if (ret == EFI_SUCCESS) { + if (dp->type == DEVICE_PATH_TYPE_END) { + dp = efi_dp_from_file(NULL, 0, + "/EFI/BOOT/" BOOTEFI_NAME); + full_path = efi_dp_append(device_path, dp); + efi_free_pool(dp); + } else { + full_path = efi_dp_dup(device_path); + } + } else { + full_path = efi_dp_dup(device_path); + } + + return full_path; +} + +/** * try_load_entry() - try to load image for boot option * * Attempt to load load-option number 'n', returning device_path and file_path @@ -64,13 +110,16 @@ static efi_status_t try_load_entry(u16 n, efi_handle_t *handle, } if (lo.attributes & LOAD_OPTION_ACTIVE) { + struct efi_device_path *file_path; u32 attributes; log_debug("trying to load \"%ls\" from %pD\n", lo.label, lo.file_path); - ret = EFI_CALL(efi_load_image(true, efi_root, lo.file_path, + file_path = expand_media_path(lo.file_path); + ret = EFI_CALL(efi_load_image(true, efi_root, file_path, NULL, 0, handle)); + efi_free_pool(file_path); if (ret != EFI_SUCCESS) { log_warning("Loading %ls '%ls' failed\n", varname, lo.label); |