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git01.mediatek.com / filogic / uboot / e7bef3ae7833f0b9b91ea644c68cec240a17ad5d / . / arch / x86 / cpu / start.S
blob: 329bb3ab35bdce43bc83692c16b60fac04529a8a [file] [log] [blame]
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]1/*
Graeme Russcbfce1d2011-04-13 19:43:28 +1000[diff] [blame]2 * U-boot - x86 Startup Code
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]3 *
Graeme Russ45fc1d82011-04-13 19:43:26 +1000[diff] [blame]4 * (C) Copyright 2008-2011
5 * Graeme Russ, <graeme.russ@gmail.com>
6 *
7 * (C) Copyright 2002
Albert ARIBAUD60fbc8d2011-08-04 18:45:45 +0200[diff] [blame]8 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]9 *
Wolfgang Denkd79de1d2013-07-08 09:37:19 +0200[diff] [blame]10 * SPDX-License-Identifier: GPL-2.0+
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]11 */
12
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]13#include <config.h>
14#include <version.h>
Graeme Russ5fb91cc2010-10-07 20:03:29 +1100[diff] [blame]15#include <asm/global_data.h>
Graeme Russ391bb952011-12-31 10:24:36 +1100[diff] [blame]16#include <asm/processor.h>
Graeme Russ93efcb22011-02-12 15:11:32 +1100[diff] [blame]17#include <asm/processor-flags.h>
Graeme Russ35368962011-12-31 22:58:15 +1100[diff] [blame]18#include <generated/generic-asm-offsets.h>
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]19
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]20.section .text
21.code32
22.globl _start
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]23.type _start, @function
Graeme Russcbfce1d2011-04-13 19:43:28 +1000[diff] [blame]24.globl _x86boot_start
25_x86boot_start:
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]26 /*
27 * This is the fail safe 32-bit bootstrap entry point. The
28 * following code is not executed from a cold-reset (actually, a
29 * lot of it is, but from real-mode after cold reset. It is
30 * repeated here to put the board into a state as close to cold
31 * reset as necessary)
32 */
33 cli
34 cld
35
Graeme Russc379b5d2011-11-08 02:33:23 +0000[diff] [blame]36 /* Turn off cache (this might require a 486-class CPU) */
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]37 movl %cr0, %eax
Graeme Russ93efcb22011-02-12 15:11:32 +1100[diff] [blame]38 orl $(X86_CR0_NW | X86_CR0_CD), %eax
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]39 movl %eax, %cr0
40 wbinvd
41
Gabe Blackef899322012-11-03 11:41:28 +0000[diff] [blame]42 /* Tell 32-bit code it is being entered from an in-RAM copy */
43 movw $GD_FLG_WARM_BOOT, %bx
44 jmp 1f
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]45_start:
Gabe Blackef899322012-11-03 11:41:28 +0000[diff] [blame]46 /*
47 * This is the 32-bit cold-reset entry point. Initialize %bx to 0
48 * in case we're preceeded by some sort of boot stub.
49 */
50 movw $GD_FLG_COLD_BOOT, %bx
511:
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]52
Graeme Russ45fc1d82011-04-13 19:43:26 +1000[diff] [blame]53 /* Load the segement registes to match the gdt loaded in start16.S */
Graeme Russ391bb952011-12-31 10:24:36 +1100[diff] [blame]54 movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
Graeme Russ3e6ec382010-10-07 20:03:21 +1100[diff] [blame]55 movw %ax, %fs
56 movw %ax, %ds
57 movw %ax, %gs
58 movw %ax, %es
59 movw %ax, %ss
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]60
Mike Williamsbf895ad2011-07-22 04:01:30 +0000[diff] [blame]61 /* Clear the interrupt vectors */
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]62 lidt blank_idt_ptr
63
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]64 /* Early platform init (setup gpio, etc ) */
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]65 jmp early_board_init
Graeme Russ157b0e92010-10-07 20:03:27 +1100[diff] [blame]66.globl early_board_init_ret
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]67early_board_init_ret:
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]68
Graeme Russbc761932011-02-12 15:11:52 +1100[diff] [blame]69 /* Initialise Cache-As-RAM */
70 jmp car_init
71.globl car_init_ret
72car_init_ret:
73 /*
74 * We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
75 * or fully initialised SDRAM - we really don't care which)
76 * starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
77 */
Graeme Russb39f12f2010-04-24 00:05:41 +1000[diff] [blame]78
Graeme Russ007818a2012-11-27 15:38:36 +0000[diff] [blame]79 /* Stack grows down from top of CAR */
80 movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE), %esp
81
82 /* Reserve space on stack for global data */
83 subl $GENERATED_GBL_DATA_SIZE, %esp
84
85 /* Align global data to 16-byte boundary */
86 andl $0xfffffff0, %esp
87
88 /* Setup first parameter to setup_gdt */
89 movl %esp, %eax
90
91 /* Reserve space for global descriptor table */
92 subl $X86_GDT_SIZE, %esp
93
94 /* Align temporary global descriptor table to 16-byte boundary */
95 andl $0xfffffff0, %esp
96
97 /* Set second parameter to setup_gdt */
98 movl %esp, %edx
99
Graeme Russ007818a2012-11-27 15:38:36 +0000[diff] [blame]100 /* Setup global descriptor table so gd->xyz works */
101 call setup_gdt
Graeme Russ35368962011-12-31 22:58:15 +1100[diff] [blame]102
Graeme Russ38183932011-02-12 15:11:54 +1100[diff] [blame]103 /* Set parameter to board_init_f() to boot flags */
Graeme Russ45fc1d82011-04-13 19:43:26 +1000[diff] [blame]104 xorl %eax, %eax
105 movw %bx, %ax
Graeme Russ5fb91cc2010-10-07 20:03:29 +1100[diff] [blame]106
Graeme Russ45fc1d82011-04-13 19:43:26 +1000[diff] [blame]107 /* Enter, U-boot! */
108 call board_init_f
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]109
110 /* indicate (lack of) progress */
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]111 movw $0x85, %ax
Graeme Russ9c44afc2011-02-12 15:11:58 +1100[diff] [blame]112 jmp die
113
Graeme Russd7755b42012-01-01 15:06:39 +1100[diff] [blame]114.globl board_init_f_r_trampoline
115.type board_init_f_r_trampoline, @function
116board_init_f_r_trampoline:
Graeme Russ9c44afc2011-02-12 15:11:58 +1100[diff] [blame]117 /*
118 * SDRAM has been initialised, U-Boot code has been copied into
119 * RAM, BSS has been cleared and relocation adjustments have been
120 * made. It is now time to jump into the in-RAM copy of U-Boot
121 *
Graeme Russd7755b42012-01-01 15:06:39 +1100[diff] [blame]122 * %eax = Address of top of new stack
Graeme Russ9c44afc2011-02-12 15:11:58 +1100[diff] [blame]123 */
124
Graeme Russ007818a2012-11-27 15:38:36 +0000[diff] [blame]125 /* Stack grows down from top of SDRAM */
Graeme Russ9c44afc2011-02-12 15:11:58 +1100[diff] [blame]126 movl %eax, %esp
127
Graeme Russ007818a2012-11-27 15:38:36 +0000[diff] [blame]128 /* Reserve space on stack for global data */
129 subl $GENERATED_GBL_DATA_SIZE, %esp
130
131 /* Align global data to 16-byte boundary */
132 andl $0xfffffff0, %esp
133
134 /* Setup first parameter to memcpy (and setup_gdt) */
135 movl %esp, %eax
136
137 /* Setup second parameter to memcpy */
138 fs movl 0, %edx
139
140 /* Set third parameter to memcpy */
141 movl $GENERATED_GBL_DATA_SIZE, %ecx
142
143 /* Copy global data from CAR to SDRAM stack */
144 call memcpy
145
146 /* Reserve space for global descriptor table */
147 subl $X86_GDT_SIZE, %esp
148
149 /* Align global descriptor table to 16-byte boundary */
150 andl $0xfffffff0, %esp
151
152 /* Set second parameter to setup_gdt */
153 movl %esp, %edx
154
Graeme Russ007818a2012-11-27 15:38:36 +0000[diff] [blame]155 /* Setup global descriptor table so gd->xyz works */
156 call setup_gdt
157
Graeme Russd7755b42012-01-01 15:06:39 +1100[diff] [blame]158 /* Re-enter U-Boot by calling board_init_f_r */
159 call board_init_f_r
Graeme Russ9c44afc2011-02-12 15:11:58 +1100[diff] [blame]160
Graeme Russc379b5d2011-11-08 02:33:23 +0000[diff] [blame]161die:
162 hlt
wdenk591dda52002-11-18 00:14:45 +0000[diff] [blame]163 jmp die
wdenk57b2d802003-06-27 21:31:46 +0000[diff] [blame]164 hlt
Graeme Russ8accbb92010-04-24 00:05:42 +1000[diff] [blame]165
166blank_idt_ptr:
167 .word 0 /* limit */
168 .long 0 /* base */
Graeme Russ786c3952011-11-08 02:33:19 +0000[diff] [blame]169
170 .p2align 2 /* force 4-byte alignment */
171
172multiboot_header:
173 /* magic */
174 .long 0x1BADB002
175 /* flags */
176 .long (1 << 16)
177 /* checksum */
178 .long -0x1BADB002 - (1 << 16)
179 /* header addr */
180 .long multiboot_header - _x86boot_start + CONFIG_SYS_TEXT_BASE
181 /* load addr */
182 .long CONFIG_SYS_TEXT_BASE
183 /* load end addr */
184 .long 0
185 /* bss end addr */
186 .long 0
187 /* entry addr */
188 .long CONFIG_SYS_TEXT_BASE