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...@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(s...@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);
 
        /*
-- 
2.7.4

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