diff options
Diffstat (limited to 'arch/i386/cpu/start.S')
| -rw-r--r-- | arch/i386/cpu/start.S | 225 |
1 files changed, 50 insertions, 175 deletions
diff --git a/arch/i386/cpu/start.S b/arch/i386/cpu/start.S index 7def8de..829468f 100644 --- a/arch/i386/cpu/start.S +++ b/arch/i386/cpu/start.S @@ -1,7 +1,7 @@ /* * U-boot - i386 Startup Code * - * Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se> + * Copyright (c) 2002 Omicron Ceti AB, Daniel Engstr�m <denaiel@omicron.se> * * See file CREDITS for list of people who contributed to this * project. @@ -25,6 +25,7 @@ #include <config.h> #include <version.h> +#include <asm/global_data.h> .section .text @@ -45,175 +46,98 @@ _i386boot_start: /* Turn of cache (this might require a 486-class CPU) */ movl %cr0, %eax - orl $0x60000000,%eax + orl $0x60000000, %eax movl %eax, %cr0 wbinvd /* Tell 32-bit code it is being entered from an in-RAM copy */ - movw $0x0000, %bx + movw $GD_FLG_WARM_BOOT, %bx _start: /* This is the 32-bit cold-reset entry point */ - movl $0x18,%eax /* Load our segement registes, the + movl $0x18, %eax /* Load our segement registes, the * gdt have already been loaded by start16.S */ - movw %ax,%fs - movw %ax,%ds - movw %ax,%gs - movw %ax,%es - movw %ax,%ss + movw %ax, %fs + movw %ax, %ds + movw %ax, %gs + movw %ax, %es + movw %ax, %ss /* Clear the interupt vectors */ lidt blank_idt_ptr - /* - * Skip low-level board and memory initialization if not starting - * from cold-reset. This allows us to do a fail safe boot-strap - * into a new build of U-Boot from a known-good boot flash - */ - movw $0x0001, %ax - cmpw %ax, %bx - jne mem_init_ret - - /* We call a few functions in the board support package - * since we have no stack yet we'll have to use %ebp - * to store the return address */ + /* Skip low-level initialization if not starting from cold-reset */ + movl %ebx, %ecx + andl $GD_FLG_COLD_BOOT, %ecx + jz skip_mem_init /* Early platform init (setup gpio, etc ) */ - mov $early_board_init_ret, %ebp jmp early_board_init +.globl early_board_init_ret early_board_init_ret: - /* The __port80 entry-point should be usabe by now */ - /* so we try to indicate progress */ - movw $0x01, %ax - movl $.progress0, %ebp - jmp show_boot_progress_asm -.progress0: - /* size memory */ - mov $mem_init_ret, %ebp - jmp mem_init + jmp mem_init +.globl mem_init_ret mem_init_ret: +skip_mem_init: /* fetch memory size (into %eax) */ - mov $get_mem_size_ret, %ebp - jmp get_mem_size + jmp get_mem_size +.globl get_mem_size_ret get_mem_size_ret: - /* - * We are now in 'Flat Protected Mode' and we know how much memory - * the board has. The (temporary) Global Descriptor Table is not - * in a 'Safe' place (it is either in Flash which can be erased or - * reprogrammed or in a fail-safe boot-strap image which could be - * over-written). - * - * Move the final gdt to a safe place (top of RAM) and load it. - * This is not a trivial excercise - the lgdt instruction does not - * have a register operand (memory only) and we may well be - * running from Flash, so self modifying code will not work here. - * To overcome this, we copy a stub into upper memory along with - * the GDT. - */ +#if CONFIG_SYS_SDRAM_ECC_ENABLE + /* Skip ECC initialization if not starting from cold-reset */ + movl %ebx, %ecx + andl $GD_FLG_COLD_BOOT, %ecx + jz init_ecc_ret + jmp init_ecc - /* Reduce upper memory limit by (Stub + GDT Pointer + GDT) */ - subl $(end_gdt_setup - start_gdt_setup), %eax - - /* Copy the GDT and Stub */ - movl $start_gdt_setup, %esi - movl %eax, %edi - movl $(end_gdt_setup - start_gdt_setup), %ecx - shrl $2, %ecx - cld - rep movsl +.globl init_ecc_ret +init_ecc_ret: +#endif - /* write the lgdt 'parameter' */ - subl $(jmp_instr - start_gdt_setup - 4), %ebp - addl %eax, %ebp - movl $(gdt_ptr - start_gdt_setup), %ebx - addl %eax, %ebx - movl %ebx, (%ebp) - - /* write the gdt address into the pointer */ - movl $(gdt_addr - start_gdt_setup), %ebp - addl %eax, %ebp - movl $(gdt - start_gdt_setup), %ebx - addl %eax, %ebx - movl %ebx, (%ebp) - - /* Save the return address */ - movl $load_gdt_ret, %ebp - - /* Load the new (safe) Global Descriptor Table */ - jmp *%eax - -load_gdt_ret: /* Check we have enough memory for stack */ movl $CONFIG_SYS_STACK_SIZE, %ecx cmpl %ecx, %eax - jae mem_ok - - /* indicate (lack of) progress */ - movw $0x81, %ax - movl $.progress0a, %ebp - jmp show_boot_progress_asm -.progress0a: - jmp die + jb die mem_ok: /* Set stack pointer to upper memory limit*/ - movl %eax, %esp - - /* indicate progress */ - movw $0x02, %ax - movl $.progress1, %ebp - jmp show_boot_progress_asm -.progress1: + movl %eax, %esp /* Test the stack */ pushl $0 - popl %eax - cmpl $0, %eax - jne no_stack + popl %ecx + cmpl $0, %ecx + jne die push $0x55aa55aa - popl %ebx - cmpl $0x55aa55aa, %ebx - je stack_ok - -no_stack: - /* indicate (lack of) progress */ - movw $0x82, %ax - movl $.progress1a, %ebp - jmp show_boot_progress_asm -.progress1a: - jmp die + popl %ecx + cmpl $0x55aa55aa, %ecx + jne die + wbinvd -stack_ok: - /* indicate progress */ - movw $0x03, %ax - movl $.progress2, %ebp - jmp show_boot_progress_asm -.progress2: + /* Determine our load offset */ + call 1f +1: popl %ecx + subl $1b, %ecx - wbinvd + /* Set the upper memory limit parameter */ + subl $CONFIG_SYS_STACK_SIZE, %eax - /* Get upper memory limit */ - movl %esp, %ecx - subl $CONFIG_SYS_STACK_SIZE, %ecx + /* Reserve space for global data */ + subl $(GD_SIZE * 4), %eax - /* Create a Stack Frame */ - pushl %ebp - movl %esp, %ebp + /* %eax points to the global data structure */ + movl %esp, (GD_RAM_SIZE * 4)(%eax) + movl %ebx, (GD_FLAGS * 4)(%eax) + movl %ecx, (GD_LOAD_OFF * 4)(%eax) - /* stack_limit parameter */ - pushl %ecx call board_init_f /* Enter, U-boot! */ /* indicate (lack of) progress */ movw $0x85, %ax - movl $.progress4a, %ebp - jmp show_boot_progress_asm -.progress4a: - die: hlt jmp die hlt @@ -221,52 +145,3 @@ die: hlt blank_idt_ptr: .word 0 /* limit */ .long 0 /* base */ - -.align 4 -start_gdt_setup: - lgdt gdt_ptr -jmp_instr: - jmp *%ebp - -.align 4 -gdt_ptr: - .word 0x30 /* limit (48 bytes = 6 GDT entries) */ -gdt_addr: - .long gdt /* base */ - - /* The GDT table ... - * - * Selector Type - * 0x00 NULL - * 0x08 Unused - * 0x10 32bit code - * 0x18 32bit data/stack - * 0x20 16bit code - * 0x28 16bit data/stack - */ - -.align 4 -gdt: - .word 0, 0, 0, 0 /* NULL */ - .word 0, 0, 0, 0 /* unused */ - - .word 0xFFFF /* 4Gb - (0x100000*0x1000 = 4Gb) */ - .word 0 /* base address = 0 */ - .word 0x9B00 /* code read/exec */ - .word 0x00CF /* granularity = 4096, 386 (+5th nibble of limit) */ - - .word 0xFFFF /* 4Gb - (0x100000*0x1000 = 4Gb) */ - .word 0x0 /* base address = 0 */ - .word 0x9300 /* data read/write */ - .word 0x00CF /* granularity = 4096, 386 (+5th nibble of limit) */ - - .word 0xFFFF /* 64kb */ - .word 0 /* base address = 0 */ - .word 0x9b00 /* data read/write */ - .word 0x0010 /* granularity = 1 (+5th nibble of limit) */ - - .word 0xFFFF /* 64kb */ - .word 0 /* base address = 0 */ - .word 0x9300 /* data read/write */ - .word 0x0010 /* granularity = 1 (+5th nibble of limit) */ -end_gdt_setup: |