diff options
Diffstat (limited to 'arch/x86/cpu/start.S')
| -rw-r--r-- | arch/x86/cpu/start.S | 77 |
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 |