/*
- * U-boot - x86 Startup Code
+ * U-Boot - x86 Startup Code
*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*/
#include <config.h>
-#include <version.h>
#include <asm/global_data.h>
#include <asm/post.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <generated/generic-asm-offsets.h>
+#include <generated/asm-offsets.h>
.section .text
.code32
.globl _x86boot_start
_x86boot_start:
/*
- * This is the fail safe 32-bit bootstrap entry point. The
- * following code is not executed from a cold-reset (actually, a
- * lot of it is, but from real-mode after cold reset. It is
- * repeated here to put the board into a state as close to cold
- * reset as necessary)
+ * This is the fail-safe 32-bit bootstrap entry point.
+ *
+ * This code is used when booting from another boot loader like
+ * coreboot or EFI. So we repeat some of the same init found in
+ * start16.
*/
cli
cld
wbinvd
/* Tell 32-bit code it is being entered from an in-RAM copy */
- movw $GD_FLG_WARM_BOOT, %bx
+ movl $GD_FLG_WARM_BOOT, %ebx
+
+ /*
+ * Zero the BIST (Built-In Self Test) value since we don't have it.
+ * It must be 0 or the previous loader would have reported an error.
+ */
+ movl $0, %ebp
+
jmp 1f
+
+ /* Add a way for tools to discover the _start entry point */
+ .align 4
+ .long 0x12345678
_start:
/*
- * This is the 32-bit cold-reset entry point. Initialize %bx to 0
- * in case we're preceeded by some sort of boot stub.
+ * This is the 32-bit cold-reset entry point, coming from start16.
+ * Set %ebx to GD_FLG_COLD_BOOT to indicate this.
*/
- movw $GD_FLG_COLD_BOOT, %bx
-1:
+ movl $GD_FLG_COLD_BOOT, %ebx
+
/* Save BIST */
movl %eax, %ebp
+1:
- /* Load the segement registes to match the gdt loaded in start16.S */
+ /* Save table pointer */
+ movl %ecx, %esi
+
+ /* Load the segement registers to match the GDT loaded in start16.S */
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
movw %ax, %fs
movw %ax, %ds
/* Clear the interrupt vectors */
lidt blank_idt_ptr
- /* Early platform init (setup gpio, etc ) */
+ /*
+ * Critical early platform init - generally not used, we prefer init
+ * to happen later when we have a console, in case something goes
+ * wrong.
+ */
jmp early_board_init
.globl early_board_init_ret
early_board_init_ret:
jmp car_init
.globl car_init_ret
car_init_ret:
+#ifndef CONFIG_HAVE_FSP
/*
* 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. The MRC requires some space at the top.
+ * and early malloc() area. The MRC requires some space at the top.
*
* Stack grows down from top of CAR. We have:
*
* top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE
* MRC area
- * global_data
- * x86 global descriptor table
+ * global_data with x86 global descriptor table
* early malloc area
* stack
* bottom-> CONFIG_SYS_CAR_ADDR
#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
#endif
+#else
+ /*
+ * When we get here after car_init(), esp points to a temporary stack
+ * and esi holds the HOB list address returned by the FSP.
+ */
+#endif
+ /* Set up global data */
+ mov %esp, %eax
+ call board_init_f_mem
+ mov %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
- post_code(POST_START_STACK)
-
- /* Zero the global data since it won't happen later */
- xorl %eax, %eax
- movl $GENERATED_GBL_DATA_SIZE, %ecx
- movl %esp, %edi
- rep stosb
-
- /* 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
+ /*
+ * Debug UART is available here although it may not be plumbed out
+ * to pins depending on the board. To use it:
+ *
+ * call debug_uart_init
+ * mov $'a', %eax
+ * call printch
+ */
-#if defined(CONFIG_SYS_MALLOC_F_LEN)
- subl $CONFIG_SYS_MALLOC_F_LEN, %esp
- movl %eax, %edx
- addl $GD_MALLOC_BASE, %edx
- movl %esp, (%edx)
+ /* Get address of global_data */
+ mov %fs:0, %edx
+#ifdef CONFIG_HAVE_FSP
+ /* Store the HOB list if we have one */
+ test %esi, %esi
+ jz skip_hob
+ movl %esi, GD_HOB_LIST(%edx)
+
+skip_hob:
+#else
+ /* Store table pointer */
+ movl %esi, GD_TABLE(%edx)
#endif
/* Store BIST */
- movl %eax, %edx
- addl $GD_BIST, %edx
- movl %ebp, (%edx)
-
- /* Set second parameter to setup_gdt */
- movl %ecx, %edx
-
- /* Setup global descriptor table so gd->xyz works */
- call setup_gdt
+ movl %ebp, GD_BIST(%edx)
/* Set parameter to board_init_f() to boot flags */
post_code(POST_START_DONE)
xorl %eax, %eax
- /* Enter, U-boot! */
+ /* Enter, U-Boot! */
call board_init_f
/* indicate (lack of) progress */
/* 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
+ /* See if we need to disable CAR */
+.weak car_uninit
+ movl $car_uninit, %eax
+ cmpl $0, %eax
+ jz 1f
- /* 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
-
- /* Setup global descriptor table so gd->xyz works */
- call setup_gdt
-
- /* Re-enter U-Boot by calling board_init_f_r */
+ call car_uninit
+1:
+ /* Re-enter U-Boot by calling board_init_f_r() */
call board_init_f_r
die:
.p2align 2 /* force 4-byte alignment */
+ /* Add a multiboot header so U-Boot can be loaded by GRUB2 */
multiboot_header:
/* magic */
- .long 0x1BADB002
+ .long 0x1badb002
/* flags */
.long (1 << 16)
/* checksum */
projects / karo-tx-uboot.git / blobdiff