This code is a little muddled, so tidy it up. Make sure that we put the GDT in the right place and set it up properly.
Signed-off-by: Simon Glass sjg@chromium.org ---
arch/x86/cpu/start.S | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index 62ac4cd..c41e1ae 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -69,6 +69,16 @@ car_init_ret: * We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM, * or fully initialised SDRAM - we really don't care which) * starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack + * and early malloc area. + * + * Stack grows down from top of CAR. We have: + * + * top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE + * global_data + * x86 global descriptor table + * early malloc area + * stack + * bottom-> CONFIG_SYS_CAR_ADDR */
/* Stack grows down from top of CAR */ @@ -86,12 +96,16 @@ car_init_ret: movl %esp, %edi rep stosb
- /* Setup first parameter to setup_gdt */ + /* Setup first parameter to setup_gdt, pointer to global_data */ movl %esp, %eax
/* Reserve space for global descriptor table */ subl $X86_GDT_SIZE, %esp
+ /* Align temporary global descriptor table to 16-byte boundary */ + andl $0xfffffff0, %esp + movl %esp, %ecx + #if defined(CONFIG_SYS_MALLOC_F_LEN) subl $CONFIG_SYS_MALLOC_F_LEN, %esp movl %eax, %edx @@ -103,14 +117,13 @@ car_init_ret: andl $0xfffffff0, %esp
/* Set second parameter to setup_gdt */ - movl %esp, %edx + movl %ecx, %edx
/* Setup global descriptor table so gd->xyz works */ call setup_gdt
/* Set parameter to board_init_f() to boot flags */ xorl %eax, %eax - movw %bx, %ax
/* Enter, U-boot! */ call board_init_f