Tom Rini | 10e4779 | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 2 | /* |
| 3 | * crt0 - C-runtime startup Code for ARM U-Boot |
| 4 | * |
| 5 | * Copyright (c) 2012 Albert ARIBAUD <albert.u.boot@aribaud.net> |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <config.h> |
| 9 | #include <asm-offsets.h> |
Benoît Thébaudeau | 73dcb27 | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 10 | #include <linux/linkage.h> |
Vikas Manocha | 976e342 | 2018-08-31 16:57:06 -0700 | [diff] [blame] | 11 | #include <asm/assembler.h> |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 12 | |
| 13 | /* |
| 14 | * This file handles the target-independent stages of the U-Boot |
| 15 | * start-up where a C runtime environment is needed. Its entry point |
| 16 | * is _main and is branched into from the target's start.S file. |
| 17 | * |
| 18 | * _main execution sequence is: |
| 19 | * |
| 20 | * 1. Set up initial environment for calling board_init_f(). |
| 21 | * This environment only provides a stack and a place to store |
| 22 | * the GD ('global data') structure, both located in some readily |
| 23 | * available RAM (SRAM, locked cache...). In this context, VARIABLE |
| 24 | * global data, initialized or not (BSS), are UNAVAILABLE; only |
Simon Glass | cb60ae8 | 2015-08-01 08:55:46 -0600 | [diff] [blame] | 25 | * CONSTANT initialized data are available. GD should be zeroed |
| 26 | * before board_init_f() is called. |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 27 | * |
| 28 | * 2. Call board_init_f(). This function prepares the hardware for |
| 29 | * execution from system RAM (DRAM, DDR...) As system RAM may not |
| 30 | * be available yet, , board_init_f() must use the current GD to |
| 31 | * store any data which must be passed on to later stages. These |
| 32 | * data include the relocation destination, the future stack, and |
| 33 | * the future GD location. |
| 34 | * |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 35 | * 3. Set up intermediate environment where the stack and GD are the |
| 36 | * ones allocated by board_init_f() in system RAM, but BSS and |
| 37 | * initialized non-const data are still not available. |
| 38 | * |
Simon Glass | cb60ae8 | 2015-08-01 08:55:46 -0600 | [diff] [blame] | 39 | * 4a.For U-Boot proper (not SPL), call relocate_code(). This function |
| 40 | * relocates U-Boot from its current location into the relocation |
| 41 | * destination computed by board_init_f(). |
| 42 | * |
| 43 | * 4b.For SPL, board_init_f() just returns (to crt0). There is no |
| 44 | * code relocation in SPL. |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 45 | * |
| 46 | * 5. Set up final environment for calling board_init_r(). This |
| 47 | * environment has BSS (initialized to 0), initialized non-const |
| 48 | * data (initialized to their intended value), and stack in system |
Simon Glass | cb60ae8 | 2015-08-01 08:55:46 -0600 | [diff] [blame] | 49 | * RAM (for SPL moving the stack and GD into RAM is optional - see |
| 50 | * CONFIG_SPL_STACK_R). GD has retained values set by board_init_f(). |
| 51 | * |
| 52 | * 6. For U-Boot proper (not SPL), some CPUs have some work left to do |
| 53 | * at this point regarding memory, so call c_runtime_cpu_setup. |
| 54 | * |
| 55 | * 7. Branch to board_init_r(). |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 56 | * |
Simon Glass | cb60ae8 | 2015-08-01 08:55:46 -0600 | [diff] [blame] | 57 | * For more information see 'Board Initialisation Flow in README. |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 58 | */ |
| 59 | |
| 60 | /* |
Andreas Dannenberg | aa4ad4b | 2019-06-04 17:55:45 -0500 | [diff] [blame] | 61 | * Macro for clearing BSS during SPL execution. Usually called during the |
| 62 | * relocation process for most boards before entering board_init_r(), but |
| 63 | * can also be done early before entering board_init_f() on plaforms that |
| 64 | * can afford it due to sufficient memory being available early. |
| 65 | */ |
| 66 | |
| 67 | .macro SPL_CLEAR_BSS |
| 68 | ldr r0, =__bss_start /* this is auto-relocated! */ |
| 69 | |
| 70 | #ifdef CONFIG_USE_ARCH_MEMSET |
| 71 | ldr r3, =__bss_end /* this is auto-relocated! */ |
| 72 | mov r1, #0x00000000 /* prepare zero to clear BSS */ |
| 73 | |
| 74 | subs r2, r3, r0 /* r2 = memset len */ |
| 75 | bl memset |
| 76 | #else |
| 77 | ldr r1, =__bss_end /* this is auto-relocated! */ |
| 78 | mov r2, #0x00000000 /* prepare zero to clear BSS */ |
| 79 | |
| 80 | clbss_l:cmp r0, r1 /* while not at end of BSS */ |
| 81 | strlo r2, [r0] /* clear 32-bit BSS word */ |
| 82 | addlo r0, r0, #4 /* move to next */ |
| 83 | blo clbss_l |
| 84 | #endif |
| 85 | .endm |
| 86 | |
| 87 | /* |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 88 | * entry point of crt0 sequence |
| 89 | */ |
| 90 | |
Benoît Thébaudeau | 73dcb27 | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 91 | ENTRY(_main) |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 92 | |
| 93 | /* |
| 94 | * Set up initial C runtime environment and call board_init_f(0). |
| 95 | */ |
| 96 | |
Kever Yang | 94ddd96 | 2019-04-02 20:41:21 +0800 | [diff] [blame] | 97 | #if defined(CONFIG_TPL_BUILD) && defined(CONFIG_TPL_NEEDS_SEPARATE_STACK) |
| 98 | ldr r0, =(CONFIG_TPL_STACK) |
| 99 | #elif defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK) |
Vikas Manocha | 40eb691 | 2016-02-05 10:43:01 -0800 | [diff] [blame] | 100 | ldr r0, =(CONFIG_SPL_STACK) |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 101 | #else |
Vikas Manocha | 40eb691 | 2016-02-05 10:43:01 -0800 | [diff] [blame] | 102 | ldr r0, =(CONFIG_SYS_INIT_SP_ADDR) |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 103 | #endif |
Vikas Manocha | 40eb691 | 2016-02-05 10:43:01 -0800 | [diff] [blame] | 104 | bic r0, r0, #7 /* 8-byte alignment for ABI compliance */ |
| 105 | mov sp, r0 |
Albert ARIBAUD | 6cb4c46 | 2015-11-25 17:56:32 +0100 | [diff] [blame] | 106 | bl board_init_f_alloc_reserve |
Simon Glass | 35375d4 | 2015-10-19 06:50:00 -0600 | [diff] [blame] | 107 | mov sp, r0 |
Albert ARIBAUD | 85260bb | 2015-11-25 17:56:33 +0100 | [diff] [blame] | 108 | /* set up gd here, outside any C code */ |
| 109 | mov r9, r0 |
Albert ARIBAUD | 6cb4c46 | 2015-11-25 17:56:32 +0100 | [diff] [blame] | 110 | bl board_init_f_init_reserve |
Simon Glass | 35375d4 | 2015-10-19 06:50:00 -0600 | [diff] [blame] | 111 | |
Andreas Dannenberg | aa4ad4b | 2019-06-04 17:55:45 -0500 | [diff] [blame] | 112 | #if defined(CONFIG_SPL_EARLY_BSS) |
| 113 | SPL_CLEAR_BSS |
| 114 | #endif |
| 115 | |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 116 | mov r0, #0 |
| 117 | bl board_init_f |
| 118 | |
| 119 | #if ! defined(CONFIG_SPL_BUILD) |
| 120 | |
| 121 | /* |
| 122 | * Set up intermediate environment (new sp and gd) and call |
Benoît Thébaudeau | a043661 | 2013-04-11 09:35:53 +0000 | [diff] [blame] | 123 | * relocate_code(addr_moni). Trick here is that we'll return |
| 124 | * 'here' but relocated. |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 125 | */ |
| 126 | |
Vikas Manocha | 40eb691 | 2016-02-05 10:43:01 -0800 | [diff] [blame] | 127 | ldr r0, [r9, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */ |
| 128 | bic r0, r0, #7 /* 8-byte alignment for ABI compliance */ |
| 129 | mov sp, r0 |
Jeroen Hofstee | f2d6076 | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 130 | ldr r9, [r9, #GD_BD] /* r9 = gd->bd */ |
| 131 | sub r9, r9, #GD_SIZE /* new GD is below bd */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 132 | |
| 133 | adr lr, here |
Jeroen Hofstee | f2d6076 | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 134 | ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 135 | add lr, lr, r0 |
rev13@wp.pl | b3b57e8 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 136 | #if defined(CONFIG_CPU_V7M) |
| 137 | orr lr, #1 /* As required by Thumb-only */ |
| 138 | #endif |
Jeroen Hofstee | f2d6076 | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 139 | ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 140 | b relocate_code |
| 141 | here: |
Albert ARIBAUD | bd6e56f | 2014-11-13 17:59:15 +0100 | [diff] [blame] | 142 | /* |
| 143 | * now relocate vectors |
| 144 | */ |
| 145 | |
| 146 | bl relocate_vectors |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 147 | |
| 148 | /* Set up final (full) environment */ |
| 149 | |
| 150 | bl c_runtime_cpu_setup /* we still call old routine here */ |
Simon Glass | d8711af | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 151 | #endif |
| 152 | #if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) |
Andreas Dannenberg | aa4ad4b | 2019-06-04 17:55:45 -0500 | [diff] [blame] | 153 | |
| 154 | #if !defined(CONFIG_SPL_EARLY_BSS) |
| 155 | SPL_CLEAR_BSS |
| 156 | #endif |
| 157 | |
Simon Glass | d8711af | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 158 | # ifdef CONFIG_SPL_BUILD |
| 159 | /* Use a DRAM stack for the rest of SPL, if requested */ |
| 160 | bl spl_relocate_stack_gd |
| 161 | cmp r0, #0 |
| 162 | movne sp, r0 |
Albert ARIBAUD | 85260bb | 2015-11-25 17:56:33 +0100 | [diff] [blame] | 163 | movne r9, r0 |
Simon Glass | d8711af | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 164 | # endif |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 165 | |
Simon Glass | d8711af | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 166 | #if ! defined(CONFIG_SPL_BUILD) |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 167 | bl coloured_LED_init |
| 168 | bl red_led_on |
Simon Glass | d8711af | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 169 | #endif |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 170 | /* call board_init_r(gd_t *id, ulong dest_addr) */ |
Jeroen Hofstee | f2d6076 | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 171 | mov r0, r9 /* gd_t */ |
| 172 | ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 173 | /* call board_init_r */ |
Tom Rini | 1c640a6 | 2017-03-18 09:01:44 -0400 | [diff] [blame] | 174 | #if CONFIG_IS_ENABLED(SYS_THUMB_BUILD) |
David Müller (ELSOFT AG) | 408a12d | 2016-02-09 16:48:28 +0100 | [diff] [blame] | 175 | ldr lr, =board_init_r /* this is auto-relocated! */ |
| 176 | bx lr |
| 177 | #else |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 178 | ldr pc, =board_init_r /* this is auto-relocated! */ |
David Müller (ELSOFT AG) | 408a12d | 2016-02-09 16:48:28 +0100 | [diff] [blame] | 179 | #endif |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 180 | /* we should not return here. */ |
Albert ARIBAUD | facdae5 | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 181 | #endif |
Benoît Thébaudeau | 73dcb27 | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 182 | |
| 183 | ENDPROC(_main) |