Hi Heinrich,
Overall, do you agree to add this feature?
On Tue, Nov 09, 2021 at 10:14:47AM +0100, Heinrich Schuchardt wrote:
>
>
> On 11/9/21 02:32, AKASHI Takahiro wrote:
> > Under the current implementation, booting from removal 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
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org>
> > ---
> > lib/efi_loader/efi_bootmgr.c | 65 +++++++++++++++++++++++++++++++++++-
> > 1 file changed, 64 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> > index 1fe19237f9a6..1d9d5858561f 100644
> > --- a/lib/efi_loader/efi_bootmgr.c
> > +++ b/lib/efi_loader/efi_bootmgr.c
> > @@ -30,6 +30,66 @@ static const struct efi_runtime_services *rs;
> > * should do normal or recovery boot.
> > */
> > +#if defined(CONFIG_ARM64)
> > +#define BOOTEFI_NAME "bootaa64.efi"
> > +#elif defined(CONFIG_ARM)
> > +#define BOOTEFI_NAME "bootarm.efi"
> > +#elif defined(CONFIG_X86_RUN_32BIT)
>
> CONFIG_X86. Check it after CONFIG_X86_64.
>
> > +#define BOOTEFI_NAME "bootia32.efi"
> > +#elif defined(CONFIG_X86_RUN_64BIT)
>
> %s/X86_RUN_64BIT/X86_64/
>
> Check this before CONFIG_X86
OK, so
#elif defined(CONFIG_X86_64)
...
#elif defined(CONFIG_X86)
...
> > +#define BOOTEFI_NAME "bootx64.efi"
> > +#elif defined(CONFIG_ARCH_RV32I)
> > +#define BOOTEFI_NAME "bootriscv32.efi"
> > +#elif defined(CONFIG_ARCH_RV64I)
> > +#define BOOTEFI_NAME "bootriscv64.efi"
> > +#else
> > +#define BOOTEFI_NAME "dummy.efi"
>
> This should result in a build error.
>
> #error Unsupported UEFI architecture
OK.
> > +#endif
>
> I think this belongs into an include file.
OK, but the only drawback is that this will make efi_api.h, which
I would like to move those definitions to, target-dependent.
As we have discussed somewhere else[1], if we want to use those include files,
we should remove sich dependencies.
Can you also make your comment on this thread[1], please?
[1] https://lists.denx.de/pipermail/u-boot/2021-November/466465.html
> According to the UEFI specification the file names are capitalized.
OK.
> > +
> > +/**
> > + * 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_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);
>
> capitalized:
> /EFI/BOOT/
OK
-Takahiro Akashi
> Best regards
>
> Heinrich
>
> > + full_path = efi_dp_append(device_path, dp);
> > + } else {
> > + full_path = efi_dp_dup(device_path);
> > + }
> > + efi_free_pool(dp);
> > + } else {
> > + full_path = efi_dp_dup(device_path);
> > + }
> > +
> > + return full_path;
> > +}
> > +
> > /**
> > * try_load_entry() - try to load image for boot option
> > *
> > @@ -68,13 +128,16 @@ 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("%s: trying to load \"%ls\" from %pD\n",
> > __func__, 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);
> >
