+/* SPDX-License-Identifier: GPL-2.0+ */
/*
- * U-boot - x86 Startup Code
+ * U-Boot - x86 Startup Code
*
- * (C) Copyright 2008-2011
- * Graeme Russ, <graeme.russ@gmail.com>
+ * This is always the first code to run from the U-Boot source. To spell it out:
*
- * (C) Copyright 2002
- * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
+ * 1. When TPL (Tertiary Program Loader) is enabled, the boot flow is
+ * TPL->SPL->U-Boot and this file is used for TPL. Then start_from_tpl.S is used
+ * for SPL and start_from_spl.S is used for U-Boot proper.
*
- * See file CREDITS for list of people who contributed to this
- * project.
+ * 2. When SPL (Secondary Program Loader) is enabled, but not TPL, the boot
+ * flow is SPL->U-Boot and this file is used for SPL. Then start_from_spl.S is
+ * used for U-Boot proper.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
+ * 3. When neither TPL nor SPL is used, this file is used for U-Boot proper.
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * (C) Copyright 2008-2011
+ * Graeme Russ, <graeme.russ@gmail.com>
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*/
#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>
+#include <linux/linkage.h>
-.section .text
+.section .text.start
.code32
.globl _start
.type _start, @function
.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
- /* Turn of cache (this might require a 486-class CPU) */
+ /* Turn off cache (this might require a 486-class CPU) */
movl %cr0, %eax
orl $(X86_CR0_NW | X86_CR0_CD), %eax
movl %eax, %cr0
wbinvd
+ /*
+ * 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 */
+ /* This is the 32-bit cold-reset entry point, coming from start16 */
+
+ /* Save BIST */
+ movl %eax, %ebp
+1:
- /* Load the segement registes to match the gdt loaded in start16.S */
- movl $0x18, %eax
+ /* Save table pointer */
+ movl %ecx, %esi
+
+#ifdef CONFIG_X86_LOAD_FROM_32_BIT
+ lgdt gdt_ptr2
+#endif
+
+ /* 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
movw %ax, %gs
/* 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:
+ post_code(POST_START)
/* Initialise Cache-As-RAM */
jmp car_init
.globl car_init_ret
car_init_ret:
+#ifdef CONFIG_USE_CAR
/*
* 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.
+ *
+ * Stack grows down from top of CAR. We have:
+ *
+ * top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE
+ * MRC area
+ * global_data with x86 global descriptor table
+ * early malloc area
+ * stack
+ * bottom-> CONFIG_SYS_CAR_ADDR
+ */
+ movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %esp
+#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
+ subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
+#endif
+#else
+ /*
+ * U-Boot enters here twice. For the first time it comes from
+ * car_init_done() with esp points to a temporary stack and esi
+ * set to zero. For the second time it comes from fsp_init_done()
+ * with esi holding the HOB list address returned by the FSP.
*/
- movl $CONFIG_SYS_INIT_SP_ADDR, %esp
+#endif
+ /* Set up global data */
+ mov %esp, %eax
+ call board_init_f_alloc_reserve
+ mov %eax, %esp
+ call board_init_f_init_reserve
+
+#ifdef CONFIG_DEBUG_UART
+ call debug_uart_init
+#endif
+
+ /* Get address of global_data */
+ mov %fs:0, %edx
+#if defined(CONFIG_USE_HOB) && !defined(CONFIG_USE_CAR)
+ /* Store the HOB list if we have one */
+ test %esi, %esi
+ jz skip_hob
+ movl %esi, GD_HOB_LIST(%edx)
+
+#ifdef CONFIG_HAVE_FSP
+ /*
+ * After fsp_init() returns, the stack has already been switched to a
+ * place within system memory as defined by CONFIG_FSP_TEMP_RAM_ADDR.
+ * Enlarge the size of malloc() pool before relocation since we have
+ * plenty of memory now.
+ */
+ subl $CONFIG_FSP_SYS_MALLOC_F_LEN, %esp
+ movl %esp, GD_MALLOC_BASE(%edx)
+#endif
+skip_hob:
+#else
+ /* Store table pointer */
+ movl %esi, GD_TABLE(%edx)
+#endif
+ /* Store BIST */
+ movl %ebp, GD_BIST(%edx)
/* Set parameter to board_init_f() to boot flags */
+ post_code(POST_START_DONE)
xorl %eax, %eax
- movw %bx, %ax
- /* Enter, U-boot! */
+ /* Enter, U-Boot! */
call board_init_f
/* indicate (lack of) progress */
movw $0x85, %ax
jmp die
-.globl relocate_code
-.type relocate_code, @function
-relocate_code:
+.globl board_init_f_r_trampoline
+.type board_init_f_r_trampoline, @function
+board_init_f_r_trampoline:
/*
* SDRAM has been initialised, U-Boot code has been copied into
* RAM, BSS has been cleared and relocation adjustments have been
* made. It is now time to jump into the in-RAM copy of U-Boot
*
- * %eax = Address of top of stack
- * %edx = Address of Global Data
- * %ecx = Base address of in-RAM copy of U-Boot
+ * %eax = Address of top of new stack
*/
- /* Setup stack in RAM */
+ /* Stack grows down from top of SDRAM */
movl %eax, %esp
- /* Setup call address of in-RAM copy of board_init_r() */
- movl $board_init_r, %ebp
- addl (GENERATED_GD_RELOC_OFF)(%edx), %ebp
+ /* See if we need to disable CAR */
+ call car_uninit
+
+ /* Re-enter U-Boot by calling board_init_f_r() */
+ call board_init_f_r
- /* Setup parameters to board_init_r() */
- movl %edx, %eax
- movl %ecx, %edx
+#ifdef CONFIG_TPL
+.globl jump_to_spl
+.type jump_to_spl, @function
+jump_to_spl:
+ /* Reset stack to the top of CAR space */
+ movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %esp
+#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
+ subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
+#endif
- /* Jump to in-RAM copy of board_init_r() */
- call *%ebp
+ jmp *%eax
+#endif
-die: hlt
+die:
+ hlt
jmp die
hlt
+WEAK(car_uninit)
+ ret
+ENDPROC(car_uninit)
+
blank_idt_ptr:
.word 0 /* limit */
.long 0 /* base */
.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 */
.long 0
/* entry addr */
.long CONFIG_SYS_TEXT_BASE
+
+#ifdef CONFIG_X86_LOAD_FROM_32_BIT
+ /*
+ * The following Global Descriptor Table is just enough to get us into
+ * 'Flat Protected Mode' - It will be discarded as soon as the final
+ * GDT is setup in a safe location in RAM
+ */
+gdt_ptr2:
+ .word 0x1f /* limit (31 bytes = 4 GDT entries - 1) */
+ .long gdt_rom2 /* base */
+
+ /* Some CPUs are picky about GDT alignment... */
+ .align 16
+.globl gdt_rom2
+gdt_rom2:
+ /*
+ * The GDT table ...
+ *
+ * Selector Type
+ * 0x00 NULL
+ * 0x08 Unused
+ * 0x10 32bit code
+ * 0x18 32bit data/stack
+ */
+ /* The NULL Desciptor - Mandatory */
+ .word 0x0000 /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x00 /* access */
+ .byte 0x00 /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /* Unused Desciptor - (matches Linux) */
+ .word 0x0000 /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x00 /* access */
+ .byte 0x00 /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /*
+ * The Code Segment Descriptor:
+ * - Base = 0x00000000
+ * - Size = 4GB
+ * - Access = Present, Ring 0, Exec (Code), Readable
+ * - Flags = 4kB Granularity, 32-bit
+ */
+ .word 0xffff /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x9b /* access */
+ .byte 0xcf /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /*
+ * The Data Segment Descriptor:
+ * - Base = 0x00000000
+ * - Size = 4GB
+ * - Access = Present, Ring 0, Non-Exec (Data), Writable
+ * - Flags = 4kB Granularity, 32-bit
+ */
+ .word 0xffff /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x93 /* access */
+ .byte 0xcf /* flags + limit_high */
+ .byte 0x00 /* base_high */
+#endif
projects / oweals / u-boot.git / blobdiff