[PATCH v2 1/4] image: Add IH_OS_EFI for EFI chain-load boot

[Cristian Ciocaltea <cristian.ciocaltea@gmail.com>]

Add a new OS type to be used for chain-loading an EFI compatible
firmware or boot loader like GRUB2, possibly in a verified boot
scenario.

Bellow is sample ITS file that generates a FIT image supporting
secure boot. Please note the presence of 'os = "efi";' line, which
identifies the currently introduced OS type:

/ {
    #address-cells = <1>;

    images {
        efi-grub {
            description = "GRUB EFI";
            data = /incbin/("EFI/BOOT/bootarm.efi");
            type = "kernel_noload";
            arch = "arm";
            os = "efi";
            compression = "none";
            load = <0x0>;
            entry = <0x0>;
            hash-1 {
                algo = "sha256";
            };
        };
    };

    configurations {
        default = "config-grub";
        config-grub {
            kernel = "efi-grub";
            signature-1 {
                algo = "sha256,rsa2048";
                sign-images = "kernel";
            };
        };
    };
};

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
---
 common/image-fit.c | 3 ++-
 common/image.c     | 1 +
 include/image.h    | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/common/image-fit.c b/common/image-fit.c
index 5c63c769de..19e313bf41 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -1925,7 +1925,8 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 		image_type == IH_TYPE_FPGA ||
 		fit_image_check_os(fit, noffset, IH_OS_LINUX) ||
 		fit_image_check_os(fit, noffset, IH_OS_U_BOOT) ||
-		fit_image_check_os(fit, noffset, IH_OS_OPENRTOS);
+		fit_image_check_os(fit, noffset, IH_OS_OPENRTOS) ||
+		fit_image_check_os(fit, noffset, IH_OS_EFI);
 
 	/*
 	 * If either of the checks fail, we should report an error, but
diff --git a/common/image.c b/common/image.c
index f17fa40c49..2e0e2b0e7f 100644
--- a/common/image.c
+++ b/common/image.c
@@ -134,6 +134,7 @@ static const table_entry_t uimage_os[] = {
 	{	IH_OS_OPENRTOS,	"openrtos",	"OpenRTOS",		},
 #endif
 	{	IH_OS_OPENSBI,	"opensbi",	"RISC-V OpenSBI",	},
+	{	IH_OS_EFI,	"efi",		"EFI Firmware" },
 
 	{	-1,		"",		"",			},
 };
diff --git a/include/image.h b/include/image.h
index f4d2aaf53e..4a280b78e7 100644
--- a/include/image.h
+++ b/include/image.h
@@ -157,6 +157,7 @@ enum {
 	IH_OS_ARM_TRUSTED_FIRMWARE,     /* ARM Trusted Firmware */
 	IH_OS_TEE,			/* Trusted Execution Environment */
 	IH_OS_OPENSBI,			/* RISC-V OpenSBI */
+	IH_OS_EFI,			/* EFI Firmware (e.g. GRUB2) */
 
 	IH_OS_COUNT,
 };
-- 
2.17.1