Before jumping to 64-bit U-Boot proper, SPL copies the cpu_call64() function to a hardcoded address 0x3000000. This can have potential conflicts with application usage. Switch the destination address to be allocated from the heap to avoid such risk.
Signed-off-by: Bin Meng bmeng.cn@gmail.com ---
arch/x86/cpu/i386/call64.S | 4 ++++ arch/x86/cpu/i386/cpu.c | 11 ++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/arch/x86/cpu/i386/call64.S b/arch/x86/cpu/i386/call64.S index 8f86728..275063c 100644 --- a/arch/x86/cpu/i386/call64.S +++ b/arch/x86/cpu/i386/call64.S @@ -79,6 +79,10 @@ lret_target: mov %eax, %eax /* Clear bits 63:32 */ jmp *%eax /* Jump to the 64-bit target */
+.globl call64_stub_size +call64_stub_size: + .long . - cpu_call64 + .data .align 16 .globl gdt64 diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c index af42431..e4b5514 100644 --- a/arch/x86/cpu/i386/cpu.c +++ b/arch/x86/cpu/i386/cpu.c @@ -523,18 +523,23 @@ int cpu_jump_to_64bit_uboot(ulong target) typedef void (*func_t)(ulong pgtable, ulong setup_base, ulong target); uint32_t *pgtable; func_t func; + char *ptr;
pgtable = (uint32_t *)PAGETABLE_BASE;
build_pagetable(pgtable);
- /* TODO(sjg@chromium.org): Find a better place for this */ - char *ptr = (char *)0x3000000; + extern long call64_stub_size; + ptr = malloc(call64_stub_size); + if (!ptr) { + printf("Failed to allocate the cpu_call64 stub\n"); + return -ENOMEM; + } char *gdt = (char *)0x3100000;
extern char gdt64[];
- memcpy(ptr, cpu_call64, 0x1000); + memcpy(ptr, cpu_call64, call64_stub_size); memcpy(gdt, gdt64, 0x100);
/*