[U-Boot] [PATCH 1/5] efi_loader: bootmgr: support BootNext and BootCurrent variable behavior

Alexander Graf
2018-12-23T02:03:51Z

On 18.12.18 06:02, AKASHI Takahiro wrote:
> See UEFI v2.7, section 3.1.2 for details of the specification.
>
> With my efishell command[1], you can try as the following:
> => efi boot add 1 SHELL ...
> => efi boot add 2 HELLO ...
> => efi boot order 1 2
> => efi bootmgr
> (starting SHELL ...)
> => efi setvar BootNext =H0200
> => efi bootmgr
> (starting HELLO ...)
> => efi dumpvar
> <snip ...>
> BootCurrent: {boot,run}(blob)
> 00000000: 02 00 ..
> BootOrder: {boot,run}(blob)
> 00000000: 01 00 02 00 ....
>
> Using "run -e" would be more human-friendly, though.
>
> [1] https://lists.denx.de/pipermail/u-boot/2018-November/346450.html
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> ---
> lib/efi_loader/efi_bootmgr.c | 37 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> index a095df3f540b..a54ae28343ce 100644
> --- a/lib/efi_loader/efi_bootmgr.c
> +++ b/lib/efi_loader/efi_bootmgr.c
> @@ -145,11 +145,21 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> efi_deserialize_load_option(&lo, load_option);
>
> if (lo.attributes & LOAD_OPTION_ACTIVE) {
> + u32 attributes;
> efi_status_t ret;
>
> debug("%s: trying to load \"%ls\" from %pD\n",
> __func__, lo.label, lo.file_path);
>
> + attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + EFI_VARIABLE_RUNTIME_ACCESS;
> + size = sizeof(n);
> + ret = rs->set_variable(L"BootCurrent",
> + (efi_guid_t *)&efi_global_variable_guid,
> + attributes, size, &n);

Every call into UEFI land (rs->foo(), bs->foo(), etc) has to go via the
EFI_CALL() macro. Otherwise we may destroy the "gd" pointer on ARM.

> + if (ret != EFI_SUCCESS)
> + goto error;
> +
> ret = efi_load_image_from_path(lo.file_path, &image);
>
> if (ret != EFI_SUCCESS)
> @@ -173,16 +183,41 @@ error:
> void *efi_bootmgr_load(struct efi_device_path **device_path,
> struct efi_device_path **file_path)
> {
> - uint16_t *bootorder;
> + u16 bootnext, *bootorder;
> + u32 attributes;
> efi_uintn_t size;
> void *image = NULL;
> int i, num;
> + efi_status_t ret;
>
> __efi_entry_check();
>
> bs = systab.boottime;
> rs = systab.runtime;
>
> + /* BootNext */
> + size = sizeof(bootnext);
> + ret = rs->get_variable(L"BootNext",
> + (efi_guid_t *)&efi_global_variable_guid,
> + NULL, &size, &bootnext);

... same here.

> + if (!bootnext)
> + goto run_list;
> +
> + attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + EFI_VARIABLE_RUNTIME_ACCESS;
> + size = 0;
> + ret = rs->set_variable(L"BootNext",
> + (efi_guid_t *)&efi_global_variable_guid,
> + attributes, size, &bootnext);

... same here.

Alex

> + if (ret != EFI_SUCCESS)
> + goto error;
> +
> + image = try_load_entry(bootnext, device_path, file_path);
> + if (image)
> + goto error;
> +
> +run_list:
> + /* BootOrder */
> bootorder = get_var(L"BootOrder", &efi_global_variable_guid, &size);
> if (!bootorder)
> goto error;
>