From ecc7fdaa9ef191e023fbc138e3466ccf05f6af20 Mon Sep 17 00:00:00 2001
From: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Date: Tue, 24 Dec 2019 18:05:39 +0200
Subject: [PATCH] bootm: Add a bootm command for type IH_OS_EFI

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@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
 cmd/Kconfig       |  7 ++++++
 common/bootm_os.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 4e29e7b3c5..a6bfa87e08 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -259,6 +259,13 @@ config CMD_BOOTM
 	help
 	  Boot an application image from the memory.
 
+config BOOTM_EFI
+	bool "Support booting UEFI FIT images"
+	depends on CMD_BOOTEFI && CMD_BOOTM && FIT
+	default y
+	help
+	  Support booting UEFI FIT images via the bootm command.
+
 config CMD_BOOTZ
 	bool "bootz"
 	help
diff --git a/common/bootm_os.c b/common/bootm_os.c
index d89ddc32b0..1d58462509 100644
--- a/common/bootm_os.c
+++ b/common/bootm_os.c
@@ -7,10 +7,12 @@
 #include <common.h>
 #include <bootm.h>
 #include <cpu_func.h>
+#include <efi_loader.h>
 #include <env.h>
 #include <fdt_support.h>
 #include <linux/libfdt.h>
 #include <malloc.h>
+#include <mapmem.h>
 #include <vxworks.h>
 #include <tee/optee.h>
 
@@ -498,6 +500,57 @@ 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;
+	efi_status_t efi_ret;
+	void *image_buf;
+
+	if (flag != BOOTM_STATE_OS_GO)
+		return 0;
+
+	/* Locate FDT, if provided */
+	ret = bootm_find_images(flag, argc, argv);
+	if (ret)
+		return ret;
+
+	/* Initialize EFI drivers */
+	efi_ret = efi_init_obj_list();
+	if (efi_ret != EFI_SUCCESS) {
+		printf("## Failed to initialize UEFI sub-system: r = %lu\n",
+		       efi_ret & ~EFI_ERROR_MASK);
+		return 1;
+	}
+
+	/* Install device tree */
+	efi_ret = efi_install_fdt(images->ft_len
+				  ? images->ft_addr : EFI_FDT_USE_INTERNAL);
+	if (efi_ret != EFI_SUCCESS) {
+		printf("## Failed to install device tree: r = %lu\n",
+		       efi_ret & ~EFI_ERROR_MASK);
+		return 1;
+	}
+
+	/* Run EFI image */
+	printf("## Transferring control to EFI (at address %08lx) ...\n",
+	       images->ep);
+	bootstage_mark(BOOTSTAGE_ID_RUN_OS);
+
+	image_buf = map_sysmem(images->ep, images->os.image_len);
+
+	efi_ret = efi_run_image(image_buf, images->os.image_len);
+	if (efi_ret != EFI_SUCCESS) {
+		printf("## Failed to run EFI image: r = %lu\n",
+		       efi_ret & ~EFI_ERROR_MASK);
+		return 1;
+	}
+
+	return 0;
+}
+#endif
+
 static boot_os_fn *boot_os[] = {
 	[IH_OS_U_BOOT] = do_bootm_standalone,
 #ifdef CONFIG_BOOTM_LINUX
@@ -534,6 +587,9 @@ 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 */
-- 
2.39.5