[PATCH v11 7/9] efi_loader: support boot from URI device path

[Ilias Apalodimas]

Kojima-san

On Wed, 8 Nov 2023 at 13:08, Masahisa Kojima <masahisa.kojima at linaro.org> wrote:
>
> This supports to boot from the URI device path.
> When user selects the URI device path, bootmgr downloads
> the file using wget into the address specified by loadaddr
> env variable.
> If the file is .iso or .img file, mount the image with blkmap
> then try to boot with the default file(e.g. EFI/BOOT/BOOTAA64.EFI).
> Since boot option indicating the default file is automatically
> created when new disk is detected, system can boot by selecting
> the automatically created blkmap boot option.
> If the file is PE-COFF file, load and start the downloaded file.
>
> The buffer used to download the ISO image file must be
> reserved to avoid the unintended access to the image and
> expose the ramdisk to the OS.
> For PE-COFF file case, this memory reservation is done
> in LoadImage Boot Service.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>  lib/efi_loader/Kconfig       |   9 +
>  lib/efi_loader/efi_bootmgr.c | 376 +++++++++++++++++++++++++++++++++++
>  2 files changed, 385 insertions(+)
>
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index d20aaab6db..5d99206dc3 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -479,4 +479,13 @@ config EFI_RISCV_BOOT_PROTOCOL
>           replace the transfer via the device-tree. The latter is not
>           possible on systems using ACPI.
>
> +config EFI_HTTP_BOOT
> +       bool "EFI HTTP Boot support"
> +       depends on CMD_DNS
> +       depends on CMD_WGET
> +       depends on BLKMAP
> +       help
> +         Enabling this option adds EFI HTTP Boot support. It allows to
> +         directly boot from network.
> +
>  endif

Since we depend on all these, I think it would be easier to 'select'
instead of 'depends on', otherwise enabling EFI_HTTP_BOOT will be very
tricky.




> + */
> +static efi_status_t search_default_file(struct udevice *dev,
> +                                       struct efi_device_path **loaded_dp)
> +{
> +       efi_status_t ret;
> +       efi_handle_t handle;
> +       u16 *default_file_name = NULL;
> +       struct efi_file_handle *root, *f;
> +       struct efi_device_path *dp = NULL, *fp = NULL;
> +       struct efi_simple_file_system_protocol *file_system;
> +       struct efi_device_path *device_path, *full_path = NULL;
> +
> +       if (dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle)) {
> +               log_warning("DM_TAG_EFI not found\n");
> +               return EFI_INVALID_PARAMETER;
> +       }
> +
> +       ret = EFI_CALL(bs->open_protocol(handle, &efi_simple_file_system_protocol_guid,
> +                                        (void **)&file_system, efi_root, NULL,
> +                                        EFI_OPEN_PROTOCOL_GET_PROTOCOL));
> +       if (ret != EFI_SUCCESS)
> +               return ret;
> +
> +       ret = EFI_CALL(file_system->open_volume(file_system, &root));
> +       if (ret != EFI_SUCCESS)
> +               return ret;
> +
> +       ret = EFI_CALL(bs->open_protocol(handle, &efi_guid_device_path,
> +                                        (void **)&device_path, efi_root, NULL,
> +                                        EFI_OPEN_PROTOCOL_GET_PROTOCOL));
> +       if (ret != EFI_SUCCESS)
> +               return ret;
> +
> +       full_path = expand_media_path(device_path);
> +       ret = efi_dp_split_file_path(full_path, &dp, &fp);
> +       if (ret != EFI_SUCCESS)
> +               goto err;
> +
> +       default_file_name = efi_dp_str(fp);
> +       efi_free_pool(dp);
> +       efi_free_pool(fp);
> +       if (!default_file_name) {
> +               ret = EFI_OUT_OF_RESOURCES;
> +               goto err;
> +       }
> +
> +       ret = EFI_CALL(root->open(root, &f, default_file_name,
> +                                 EFI_FILE_MODE_READ, 0));
> +       efi_free_pool(default_file_name);
> +       if (ret != EFI_SUCCESS)
> +               goto err;
> +
> +       EFI_CALL(f->close(f));\

This closes the file correctly, but the volume is still open. Don't we need
EFI_CALL(root->close(root) as well?

[...]

With the above fixed
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>