From bc1a8f0d7a57fbc1b0c03f323412a56761c82240 Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Thu, 31 Jan 2019 08:22:14 -0800
Subject: [PATCH] x86: Use the existing GDT in the ROM for 64-bit U-Boot proper
It is unnecessary to use a RAM version GDT for 64-bit U-Boot proper.
In fact we can just use the ROM version directly, which not only
eliminates the risk of being overwritten by application, but also
removes the complexity of patching the cpu_call64().
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
arch/x86/cpu/i386/cpu.c | 14 --------------
1 file changed, 14 deletions(-)
diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c
index e4b551452d..3bde44ebf5 100644
--- a/arch/x86/cpu/i386/cpu.c
+++ b/arch/x86/cpu/i386/cpu.c
@@ -535,23 +535,9 @@ int cpu_jump_to_64bit_uboot(ulong target)
printf("Failed to allocate the cpu_call64 stub\n");
return -ENOMEM;
}
- char *gdt = (char *)0x3100000;
-
- extern char gdt64[];
-
memcpy(ptr, cpu_call64, call64_stub_size);
- memcpy(gdt, gdt64, 0x100);
- /*
- * TODO(sjg@chromium.org): This manually inserts the pointers into
- * the code. Tidy this up to avoid this.
- */
func = (func_t)ptr;
- ulong ofs = (ulong)cpu_call64 - (ulong)ptr;
- *(ulong *)(ptr + 7) = (ulong)gdt;
- *(ulong *)(ptr + 0xc) = (ulong)gdt + 2;
- *(ulong *)(ptr + 0x13) = (ulong)gdt;
- *(ulong *)(ptr + 0x117 - 0xd4) -= ofs;
/*
* Copy U-Boot from ROM
--
2.39.5