[PATCH v2 2/4] bootm: Add a bootm command for type IH_OS_EFI

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

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>
---
 cmd/Kconfig       |  7 ++++++
 common/bootm_os.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/cmd/Kconfig b/cmd/Kconfig
index cf982ff65e..39fa87082d 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
diff --git a/common/bootm_os.c b/common/bootm_os.c
index 6fb7d658da..7aa76052b9 100644
--- a/common/bootm_os.c
+++ b/common/bootm_os.c
@@ -6,10 +6,12 @@
 
 #include <common.h>
 #include <bootm.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>
 
@@ -462,6 +464,62 @@ 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;
+	uintptr_t fdt_addr;
+	void *image_buf;
+
+	if (flag != BOOTM_STATE_OS_GO)
+		return 0;
+
+	/* Locate EFI binary and 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("## Error: Cannot initialize UEFI sub-system, r = %lu\n",
+		       efi_ret & ~EFI_ERROR_MASK);
+		return 1;
+	}
+
+	/* Install device tree */
+	if (images->ft_len)
+		fdt_addr = (uintptr_t)images->ft_addr;
+	else
+		fdt_addr = EFI_FDT_USE_INTERNAL;
+
+	efi_ret = efi_install_fdt(fdt_addr);
+	if (efi_ret != EFI_SUCCESS) {
+		printf("## Error: Cannot 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("## Error: Cannot 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
@@ -498,6 +556,9 @@ 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 */
-- 
2.17.1