[U-Boot] [PATCH v5 24/30] efi_loader: Add distro boot script for removable media

[Alexander Graf <agraf@suse.de>]

On 04.03.16 01:10, Alexander Graf wrote:
> UEFI defines a simple boot protocol for removable media. There we should look
> at the EFI (first GPT FAT) partition and search for /efi/boot/bootXXX.efi with
> XXX being different between different platforms (x86, x64, arm, aa64, ...).
> 
> This patch implements a simple version of that protocol for the default distro
> boot script. With this we can automatically boot from valid UEFI enabled
> removable media.
> 
> Because from all I could see U-Boot by default doesn't deliver device tree
> blobs with its firmware, we also need to load the dtb from somewhere. Traverse
> the same EFI partition for an fdt file that fits our current board so that
> an OS receives a valid device tree when booted automatically.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> Reviewed-by: Simon Glass <sjg@chromium.org>
> ---
>  include/config_distro_bootcmd.h | 47 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/include/config_distro_bootcmd.h b/include/config_distro_bootcmd.h
> index 37c6b43..c19f1b0 100644
> --- a/include/config_distro_bootcmd.h
> +++ b/include/config_distro_bootcmd.h
> @@ -90,6 +90,48 @@
>  	BOOT_TARGET_DEVICES_references_UBIFS_without_CONFIG_CMD_UBIFS
>  #endif
>  
> +#ifdef CONFIG_EFI_LOADER
> +#if defined(CONFIG_ARM64)
> +#define BOOTEFI_NAME "bootaa64.efi"
> +#elif defined(CONFIG_ARM)
> +#define BOOTEFI_NAME "bootarm.efi"
> +#endif
> +#endif
> +
> +#ifdef BOOTEFI_NAME
> +#define BOOTENV_SHARED_EFI                                                \
> +	"boot_efi_binary="                                                \
> +		"load ${devtype} ${devnum}:${distro_bootpart} "           \
> +			"${kernel_addr_r} efi/boot/"BOOTEFI_NAME"; "      \
> +		"bootefi ${kernel_addr_r}\0"                              \
> +	\
> +	"load_efi_dtb="                                                   \
> +		"load ${devtype} ${devnum}:${distro_bootpart} "           \
> +			"${fdt_addr_r} ${prefix}${fdt_name}; "           \
> +		"fdt addr ${fdt_addr_r}\0"                                \
> +	\
> +	"efi_dtb_prefixes=/ /dtb/ /dtb/current/\0"                        \
> +	"scan_dev_for_efi="                                               \
> +		"for prefix in ${efi_dtb_prefixes}; do "                  \
> +			"if test -e ${devtype} "                          \
> +					"${devnum}:${distro_bootpart} "   \
> +					"${prefix}${fdt_name}; then "     \
> +				"run load_efi_dtb; "                      \
> +			"fi;"                                             \
> +		"done;"                                                   \
> +		"if test -e ${devtype} ${devnum}:${distro_bootpart} "     \
> +					"efi/boot/"BOOTEFI_NAME"; then "  \
> +				"echo Found EFI removable media binary "  \
> +					"efi/boot/"BOOTEFI_NAME"; "       \
> +				"run boot_efi_binary; "                   \
> +				"echo EFI LOAD FAILED: continuing...; "   \
> +		"fi; "

Whoever applies this, please also apply the patch below on top and
squash it in (or tell me to resend). Without the fix, we end up slurping
the boot_prefix variable into the scan_dev_for_efi variable.


Alex

diff --git a/include/config_distro_bootcmd.h
b/include/config_distro_bootcmd.h
index e7d7002..ad9045e 100644
--- a/include/config_distro_bootcmd.h
+++ b/include/config_distro_bootcmd.h
@@ -125,7 +125,7 @@
                                        "efi/boot/"BOOTEFI_NAME"; "       \
                                "run boot_efi_binary; "                   \
                                "echo EFI LOAD FAILED: continuing...; "   \
-               "fi; "
+               "fi; \0"
 #define SCAN_DEV_FOR_EFI "run scan_dev_for_efi;"
 #else
 #define BOOTENV_SHARED_EFI