summaryrefslogtreecommitdiff
path: root/arch/x86/cpu/start.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/cpu/start.S')
-rw-r--r--arch/x86/cpu/start.S77
1 files changed, 69 insertions, 8 deletions
diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
index ee0dabe..e960e21 100644
--- a/arch/x86/cpu/start.S
+++ b/arch/x86/cpu/start.S
@@ -55,8 +55,16 @@ _x86boot_start:
movl %eax, %cr0
wbinvd
+ /* Tell 32-bit code it is being entered from an in-RAM copy */
+ movw $GD_FLG_WARM_BOOT, %bx
+ jmp 1f
_start:
- /* This is the 32-bit cold-reset entry point */
+ /*
+ * This is the 32-bit cold-reset entry point. Initialize %bx to 0
+ * in case we're preceeded by some sort of boot stub.
+ */
+ movw $GD_FLG_COLD_BOOT, %bx
+1:
/* Load the segement registes to match the gdt loaded in start16.S */
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
@@ -83,13 +91,33 @@ car_init_ret:
* or fully initialised SDRAM - we really don't care which)
* starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
*/
- movl $CONFIG_SYS_INIT_SP_ADDR, %esp
- /* Initialise the Global Data Pointer */
- movl $CONFIG_SYS_INIT_GD_ADDR, %eax
- movl %eax, %edx
- addl $GENERATED_GBL_DATA_SIZE, %edx
- call init_gd;
+ /* Stack grows down from top of CAR */
+ movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE), %esp
+
+ /* Reserve space on stack for global data */
+ subl $GENERATED_GBL_DATA_SIZE, %esp
+
+ /* Align global data to 16-byte boundary */
+ andl $0xfffffff0, %esp
+
+ /* Setup first parameter to setup_gdt */
+ 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
+
+ /* Set second parameter to setup_gdt */
+ movl %esp, %edx
+
+ /* gd->gd_addr = gd (Required to allow gd->xyz to work) */
+ movl %eax, (%eax)
+
+ /* Setup global descriptor table so gd->xyz works */
+ call setup_gdt
/* Set parameter to board_init_f() to boot flags */
xorl %eax, %eax
@@ -113,9 +141,42 @@ board_init_f_r_trampoline:
* %eax = Address of top of new stack
*/
- /* Setup stack in RAM */
+ /* Stack grows down from top of SDRAM */
movl %eax, %esp
+ /* Reserve space on stack for global data */
+ subl $GENERATED_GBL_DATA_SIZE, %esp
+
+ /* Align global data to 16-byte boundary */
+ andl $0xfffffff0, %esp
+
+ /* Setup first parameter to memcpy (and setup_gdt) */
+ movl %esp, %eax
+
+ /* Setup second parameter to memcpy */
+ fs movl 0, %edx
+
+ /* Set third parameter to memcpy */
+ movl $GENERATED_GBL_DATA_SIZE, %ecx
+
+ /* Copy global data from CAR to SDRAM stack */
+ call memcpy
+
+ /* Reserve space for global descriptor table */
+ subl $X86_GDT_SIZE, %esp
+
+ /* Align global descriptor table to 16-byte boundary */
+ andl $0xfffffff0, %esp
+
+ /* Set second parameter to setup_gdt */
+ movl %esp, %edx
+
+ /* gd->gd_addr = gd (Required to allow gd->xyz to work) */
+ movl %eax, (%eax)
+
+ /* Setup global descriptor table so gd->xyz works */
+ call setup_gdt
+
/* Re-enter U-Boot by calling board_init_f_r */
call board_init_f_r