[PATCH 10/18] x86: Add 64-bit entries to the GDT

[Simon Glass]

At present it is not possible to execution 64-bit code without
installing an entire new Global Descriptor Table. This is inconvenient
since kvm does not seem to like switching into long mode with a new
table.

It isn't actually necessary, since we can just extend the existing
table. Add some new entries to this effect.

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

 arch/x86/cpu/i386/cpu.c          | 3 +++
 arch/x86/include/asm/processor.h | 5 ++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c
index a51a24498a7..3bbad3b2eca 100644
--- a/arch/x86/cpu/i386/cpu.c
+++ b/arch/x86/cpu/i386/cpu.c
@@ -160,6 +160,9 @@ void arch_setup_gd(gd_t *new_gd)
 
 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
+	gdt_addr[X86_GDT_ENTRY_64BIT_CS] = GDT_ENTRY(0xaf9b, 0, 0xfffff);
+	gdt_addr[X86_GDT_ENTRY_64BIT_TS1] = GDT_ENTRY(0x8980, 0, 0xfffff);
+	gdt_addr[X86_GDT_ENTRY_64BIT_TS2] = 0;
 
 	load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
 	load_ds(X86_GDT_ENTRY_32BIT_DS);
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index d7b68367861..ad8240be387 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -18,7 +18,10 @@
 #define X86_GDT_ENTRY_16BIT_DS		6
 #define X86_GDT_ENTRY_16BIT_FLAT_CS	7
 #define X86_GDT_ENTRY_16BIT_FLAT_DS	8
-#define X86_GDT_NUM_ENTRIES		9
+#define X86_GDT_ENTRY_64BIT_CS		9
+#define X86_GDT_ENTRY_64BIT_TS1		10
+#define X86_GDT_ENTRY_64BIT_TS2		11
+#define X86_GDT_NUM_ENTRIES		12
 
 #define X86_GDT_SIZE		(X86_GDT_NUM_ENTRIES * X86_GDT_ENTRY_SIZE)
 
-- 
2.34.1