[U-Boot] [PATCH 38/48] efi: Add 64-bit payload support

[Simon Glass]

Most EFI implementations use 64-bit. Add a way to build U-Boot as a 64-bit
EFI payload. The payload unpacks a (32-bit) U-Boot and starts it. This can
be enabled for x86 boards at present.

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

 Makefile                     |  2 +-
 arch/x86/config.mk           | 11 +++++++++
 arch/x86/include/asm/types.h |  5 +++-
 lib/efi/efi_stub.c           | 58 ++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 69 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 9f863e1..6e3edb4 100644
--- a/Makefile
+++ b/Makefile
@@ -1109,7 +1109,7 @@ u-boot-payload.lds: $(LDSCRIPT_EFI) FORCE
 u-boot-payload: u-boot-dtb.bin.o u-boot-payload.lds \
 		FORCE
 	$(LD) $(LDFLAGS_EFI) -o $@ \
-      -T u-boot-payload.lds \
+      -T u-boot-payload.lds arch/x86/cpu/call32.o \
       lib/efi/efi.o lib/efi/efi_stub.o u-boot-dtb.bin.o \
       $(addprefix arch/$(ARCH)/lib/,$(EFISTUB))
 
diff --git a/arch/x86/config.mk b/arch/x86/config.mk
index bb0b254..5107b43 100644
--- a/arch/x86/config.mk
+++ b/arch/x86/config.mk
@@ -15,7 +15,10 @@ PF_CPPFLAGS_X86   := $(call cc-option, -fno-toplevel-reorder, \
 
 PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_X86)
 PLATFORM_CPPFLAGS += -fno-dwarf2-cfi-asm
+
+ifeq ($(CONFIG_X86_64),)
 PLATFORM_CPPFLAGS += -march=i386 -m32
+endif
 
 PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden
 
@@ -33,11 +36,19 @@ OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \
 CFLAGS_NON_EFI := -mregparm=3
 CFLAGS_EFI := -fpic -fshort-wchar $(call cc-option, -mno-red-zone)
 
+ifeq ($(CONFIG_X86_64)$(CONFIG_EFI_STUB_64BIT),)
 EFIARCH=ia32
+else
+EFIARCH=x86_64
+endif
 
 LDSCRIPT_EFI := $(srctree)/$(CPUDIR)/efi/elf_$(EFIARCH)_efi.lds
+EFISTUB := crt0-efi-$(EFIARCH).o reloc_$(EFIARCH).o
 OBJCOPYFLAGS_EFI += --target=efi-app-$(EFIARCH)
 
+CPPFLAGS_REMOVE_crt0-efi-$(EFIARCH).o += $(CFLAGS_NON_EFI)
+CPPFLAGS_crt0-efi-$(EFIARCH).o += $(CFLAGS_EFI)
+
 ifeq ($(CONFIG_ARCH_EFI),y)
 
 PLATFORM_CPPFLAGS += $(CFLAGS_EFI)
diff --git a/arch/x86/include/asm/types.h b/arch/x86/include/asm/types.h
index e272c90..766617f 100644
--- a/arch/x86/include/asm/types.h
+++ b/arch/x86/include/asm/types.h
@@ -44,8 +44,11 @@ typedef __INT64_TYPE__ s64;
 typedef __UINT64_TYPE__ u64;
 #endif
 
+#ifdef CONFIG_EFI_STUB_64BIT
+#define BITS_PER_LONG 64
+#else
 #define BITS_PER_LONG 32
-
+#endif
 /* Dma addresses are 32-bits wide.  */
 
 typedef u32 dma_addr_t;
diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c
index e3b7cdb..36f14ff 100644
--- a/lib/efi/efi_stub.c
+++ b/lib/efi/efi_stub.c
@@ -6,8 +6,8 @@
  * EFI information obtained here:
  * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES
  *
- * Loads a payload (U-Boot) within the EFI environment. This is built as a
- * 32-bit EFI application.
+ * Loads a payload (U-Boot) within the EFI environment. This is built as an
+ * EFI application. It can be built either in 32-bit or 64-bit mode.
  */
 
 #include <common.h>
@@ -116,12 +116,12 @@ void *memset(void *inptr, int ch, size_t size)
 
 static void jump_to_uboot(ulong cs32, ulong addr, ulong info)
 {
+#ifdef CONFIG_EFI_STUB_32BIT
 	typedef void (*func_t)(int bist, int unused, ulong info);
 
-#ifdef CONFIG_EFI_STUB_32BIT
 	((func_t)addr)(bist, 0, info);
 #else
-	/* TODO: Implement this */
+	cpu_call32(cs32, CONFIG_SYS_TEXT_BASE, info);
 #endif
 }
 
@@ -151,7 +151,55 @@ static int get_codeseg32(void)
 {
 	int cs32 = 0;
 
-	/* TODO(sjg): Implement this for 64-bit mode */
+#ifdef CONFIG_EFI_STUB_64BIT
+	struct desctab_info gdt;
+	uint64_t *ptr;
+	int i;
+
+	get_gdt(&gdt);
+	for (ptr = (uint64_t *)(unsigned long)gdt.addr, i = 0; i < gdt.limit;
+	     i += 8, ptr++) {
+		uint64_t desc = *ptr;
+
+		if ((desc & GDT_PRESENT) && (desc && GDT_NOTSYS) &&
+		    !(desc & GDT_LONG) && (desc & GDT_4GB) &&
+		    (desc & GDT_32BIT) && (desc & GDT_CODE)) {
+			cs32 = i;
+			break;
+		}
+	}
+
+#ifdef DEBUG
+	puts("\ngdt: ");
+	printhex8(gdt.limit);
+	puts(", addr: ");
+	printhex8(gdt.addr >> 32);
+	printhex8(gdt.addr);
+	for (i = 0; i < gdt.limit; i += 8) {
+		uint32_t *ptr = (uint32_t *)((unsigned long)gdt.addr + i);
+
+		puts("\n");
+		printhex2(i);
+		puts(": ");
+		printhex8(ptr[1]);
+		puts("  ");
+		printhex8(ptr[0]);
+	}
+	puts("\n ");
+	puts("32-bit code segment: ");
+	printhex2(cs32);
+	puts("\n ");
+
+	puts("page_table: ");
+	printhex8(read_cr3());
+	puts("\n ");
+#endif
+	if (!cs32) {
+		puts("Can't find 32-bit code segment\n");
+		return -ENOENT;
+	}
+#endif
+
 	return cs32;
 }
 
-- 
2.4.3.573.g4eafbef