[U-Boot] [PATCH 2/2] bootm: Add a bootm command for type IH_OS_EFI

[Heinrich Schuchardt]

On 11/24/19 9:11 PM, Cristian Ciocaltea wrote:
> Add support for booting EFI binaries contained in FIT images.
> A typical usage scenario is chain-loading GRUB2 in a verified
> boot environment.
>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at gmail.com>
> ---
>   cmd/Kconfig       |  9 ++++++++-
>   cmd/bootefi.c     |  2 +-
>   common/bootm_os.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
>   include/bootm.h   |  2 ++
>   4 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index cf982ff65e..1bec840f5a 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -263,6 +263,13 @@ config CMD_BOOTI
>   	help
>   	  Boot an AArch64 Linux Kernel image from memory.
>
> +config BOOTM_EFI
> +	bool "Support booting EFI OS images"
> +	depends on CMD_BOOTEFI
> +	default y
> +	help
> +	  Support booting EFI images via the bootm command.
> +
>   config BOOTM_LINUX
>   	bool "Support booting Linux OS images"
>   	depends on CMD_BOOTM || CMD_BOOTZ || CMD_BOOTI
> @@ -316,7 +323,7 @@ config CMD_BOOTEFI
>   	depends on EFI_LOADER
>   	default y
>   	help
> -	  Boot an EFI image from memory.
> +	  Boot an EFI binary from memory.
>
>   config CMD_BOOTEFI_HELLO_COMPILE
>   	bool "Compile a standard EFI hello world binary for testing"
> diff --git a/cmd/bootefi.c b/cmd/bootefi.c
> index f613cce7e2..f25d639dfe 100644
> --- a/cmd/bootefi.c
> +++ b/cmd/bootefi.c
> @@ -553,7 +553,7 @@ static int do_efi_selftest(void)
>    * @argv:	command line arguments
>    * Return:	status code
>    */
> -static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>   {
>   	efi_status_t ret;
>
> diff --git a/common/bootm_os.c b/common/bootm_os.c
> index 6fb7d658da..706151913a 100644
> --- a/common/bootm_os.c
> +++ b/common/bootm_os.c
> @@ -462,6 +462,47 @@ static int do_bootm_tee(int flag, int argc, char * const argv[],
>   }
>   #endif
>
> +#ifdef CONFIG_BOOTM_EFI
> +static int do_bootm_efi(int flag, int argc, char * const argv[],
> +			bootm_headers_t *images)
> +{
> +	int ret;
> +	int local_argc = 2;
> +	char *local_args[3];
> +	char str_efi_addr[16];
> +	char str_fdt_addr[16];
> +
> +	if (flag != BOOTM_STATE_OS_GO)
> +		return 0;
> +
> +	/* Locate FDT etc */
> +	ret = bootm_find_images(flag, argc, argv);
> +	if (ret)
> +		return ret;
> +
> +	printf("## Transferring control to EFI (at address %08lx) ...\n",
> +	       images->ep);
> +	bootstage_mark(BOOTSTAGE_ID_RUN_OS);
> +
> +	local_args[0] = argv[0];
> +
> +	/* Write efi addr into string */
> +	sprintf(str_efi_addr, "%lx", images->ep);

I think we should avoid transferring arguments as strings. It is
preferable to separate do_bootefi() into an argument parser and an
execution part.

Let's CC the developers who have contributed to common/bootm_os.c.

Best regards

Heinrich

> +	/* and provide it via the arguments */
> +	local_args[1] = str_efi_addr;
> +
> +	if (images->ft_len) {
> +		/* Write fdt addr into string */
> +		sprintf(str_fdt_addr, "%lx", (unsigned long)images->ft_addr);
> +		/* and provide it via the arguments */
> +		local_args[2] = str_fdt_addr;
> +		local_argc = 3;
> +	}
> +
> +	return do_bootefi(NULL, 0, local_argc, local_args);
> +}
> +#endif
> +
>   static boot_os_fn *boot_os[] = {
>   	[IH_OS_U_BOOT] = do_bootm_standalone,
>   #ifdef CONFIG_BOOTM_LINUX
> @@ -498,6 +539,9 @@ static boot_os_fn *boot_os[] = {
>   #ifdef CONFIG_BOOTM_OPTEE
>   	[IH_OS_TEE] = do_bootm_tee,
>   #endif
> +#ifdef CONFIG_BOOTM_EFI
> +	[IH_OS_EFI] = do_bootm_efi,
> +#endif
>   };
>
>   /* Allow for arch specific config before we boot */
> diff --git a/include/bootm.h b/include/bootm.h
> index edeeacb0df..a0da86dc32 100644
> --- a/include/bootm.h
> +++ b/include/bootm.h
> @@ -37,7 +37,9 @@ typedef int boot_os_fn(int flag, int argc, char * const argv[],
>   extern boot_os_fn do_bootm_linux;
>   extern boot_os_fn do_bootm_vxworks;
>
> +int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
>   int do_bootelf(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
> +
>   void lynxkdi_boot(image_header_t *hdr);
>
>   boot_os_fn *bootm_os_get_boot_func(int os);
>