From: Bin Meng Date: Thu, 31 Jan 2019 16:22:14 +0000 (-0800) Subject: x86: Use the existing GDT in the ROM for 64-bit U-Boot proper X-Git-Tag: v2019.04-rc2~15^2~1 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=bc1a8f0d7a57fbc1b0c03f323412a56761c82240;p=oweals%2Fu-boot.git 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 Reviewed-by: Simon Glass --- 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