[PATCH v3 05/12] x86: Exit EFI boot services before starting kernel

[Simon Glass]

When running the EFI app, we need to exit boot services before jumping
to Linux.

At some point it may be possible to jump to Linux and pass on the system
table, and:

  * install the device-tree as configuration table
  * use LoadImage() to load the kernel image (e.g. from memory)
  * start the image with StartImage()

This should allow the Linux efistub to be used. For now, this is not
implemented.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
- Update commit message based on Heinrich's comments

 arch/x86/lib/bootm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c
index 9beb376bb9c2..61cb7bc61168 100644
--- a/arch/x86/lib/bootm.c
+++ b/arch/x86/lib/bootm.c
@@ -10,6 +10,7 @@
 #include <common.h>
 #include <bootstage.h>
 #include <command.h>
+#include <efi.h>
 #include <hang.h>
 #include <log.h>
 #include <asm/global_data.h>
@@ -156,6 +157,23 @@ int boot_linux_kernel(ulong setup_base, ulong entry, bool image_64bit)
 #ifdef CONFIG_SYS_COREBOOT
 	timestamp_add_now(TS_U_BOOT_START_KERNEL);
 #endif
+
+	/*
+	 * Exit EFI boot services just before jumping, after all console
+	 * output, since the console won't be available afterwards.
+	 */
+	if (IS_ENABLED(CONFIG_EFI_APP)) {
+		int ret;
+
+		ret = efi_store_memory_map(efi_get_priv());
+		if (ret)
+			return ret;
+		printf("Exiting EFI boot services\n");
+		ret = efi_call_exit_boot_services();
+		if (ret)
+			return ret;
+	}
+
 	if (image_64bit) {
 		if (!cpu_has_64bit()) {
 			puts("Cannot boot 64-bit kernel on 32-bit machine\n");
-- 
2.40.0.rc1.284.g88254d51c5-goog