Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 1 | /* |
| 2 | * crt0 - C-runtime startup Code for ARM U-Boot |
| 3 | * |
| 4 | * Copyright (c) 2012 Albert ARIBAUD <albert.u.boot@aribaud.net> |
| 5 | * |
Wolfgang Denk | 1a45966 | 2013-07-08 09:37:19 +0200 | [diff] [blame] | 6 | * SPDX-License-Identifier: GPL-2.0+ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 7 | */ |
| 8 | |
| 9 | #include <config.h> |
| 10 | #include <asm-offsets.h> |
Benoît Thébaudeau | 9c5feab | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 11 | #include <linux/linkage.h> |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 12 | #ifdef CONFIG_CPU_V7M |
| 13 | #include <asm/armv7m.h> |
| 14 | #endif |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 15 | |
| 16 | /* |
| 17 | * This file handles the target-independent stages of the U-Boot |
| 18 | * start-up where a C runtime environment is needed. Its entry point |
| 19 | * is _main and is branched into from the target's start.S file. |
| 20 | * |
| 21 | * _main execution sequence is: |
| 22 | * |
| 23 | * 1. Set up initial environment for calling board_init_f(). |
| 24 | * This environment only provides a stack and a place to store |
| 25 | * the GD ('global data') structure, both located in some readily |
| 26 | * available RAM (SRAM, locked cache...). In this context, VARIABLE |
| 27 | * global data, initialized or not (BSS), are UNAVAILABLE; only |
Simon Glass | ed64190 | 2015-08-01 08:55:46 -0600 | [diff] [blame^] | 28 | * CONSTANT initialized data are available. GD should be zeroed |
| 29 | * before board_init_f() is called. |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 30 | * |
| 31 | * 2. Call board_init_f(). This function prepares the hardware for |
| 32 | * execution from system RAM (DRAM, DDR...) As system RAM may not |
| 33 | * be available yet, , board_init_f() must use the current GD to |
| 34 | * store any data which must be passed on to later stages. These |
| 35 | * data include the relocation destination, the future stack, and |
| 36 | * the future GD location. |
| 37 | * |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 38 | * 3. Set up intermediate environment where the stack and GD are the |
| 39 | * ones allocated by board_init_f() in system RAM, but BSS and |
| 40 | * initialized non-const data are still not available. |
| 41 | * |
Simon Glass | ed64190 | 2015-08-01 08:55:46 -0600 | [diff] [blame^] | 42 | * 4a.For U-Boot proper (not SPL), call relocate_code(). This function |
| 43 | * relocates U-Boot from its current location into the relocation |
| 44 | * destination computed by board_init_f(). |
| 45 | * |
| 46 | * 4b.For SPL, board_init_f() just returns (to crt0). There is no |
| 47 | * code relocation in SPL. |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 48 | * |
| 49 | * 5. Set up final environment for calling board_init_r(). This |
| 50 | * environment has BSS (initialized to 0), initialized non-const |
| 51 | * data (initialized to their intended value), and stack in system |
Simon Glass | ed64190 | 2015-08-01 08:55:46 -0600 | [diff] [blame^] | 52 | * RAM (for SPL moving the stack and GD into RAM is optional - see |
| 53 | * CONFIG_SPL_STACK_R). GD has retained values set by board_init_f(). |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 54 | * |
Simon Glass | ed64190 | 2015-08-01 08:55:46 -0600 | [diff] [blame^] | 55 | * 6. For U-Boot proper (not SPL), some CPUs have some work left to do |
| 56 | * at this point regarding memory, so call c_runtime_cpu_setup. |
| 57 | * |
| 58 | * 7. Branch to board_init_r(). |
| 59 | * |
| 60 | * For more information see 'Board Initialisation Flow in README. |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 61 | */ |
| 62 | |
| 63 | /* |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 64 | * entry point of crt0 sequence |
| 65 | */ |
| 66 | |
Benoît Thébaudeau | 9c5feab | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 67 | ENTRY(_main) |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 68 | |
| 69 | /* |
| 70 | * Set up initial C runtime environment and call board_init_f(0). |
| 71 | */ |
| 72 | |
Benoît Thébaudeau | 66f30bf | 2013-04-11 09:36:01 +0000 | [diff] [blame] | 73 | #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK) |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 74 | ldr sp, =(CONFIG_SPL_STACK) |
| 75 | #else |
| 76 | ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) |
| 77 | #endif |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 78 | #if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */ |
| 79 | mov r3, sp |
| 80 | bic r3, r3, #7 |
| 81 | mov sp, r3 |
| 82 | #else |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 83 | bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 84 | #endif |
Simon Glass | aae2aef | 2014-07-10 22:23:26 -0600 | [diff] [blame] | 85 | mov r2, sp |
Andreas Bießmann | 6ba2bc8 | 2013-11-27 16:09:29 +0100 | [diff] [blame] | 86 | sub sp, sp, #GD_SIZE /* allocate one GD above SP */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 87 | #if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */ |
| 88 | mov r3, sp |
| 89 | bic r3, r3, #7 |
| 90 | mov sp, r3 |
| 91 | #else |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 92 | bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 93 | #endif |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 94 | mov r9, sp /* GD is above SP */ |
Simon Glass | aae2aef | 2014-07-10 22:23:26 -0600 | [diff] [blame] | 95 | mov r1, sp |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 96 | mov r0, #0 |
Simon Glass | aae2aef | 2014-07-10 22:23:26 -0600 | [diff] [blame] | 97 | clr_gd: |
| 98 | cmp r1, r2 /* while not at end of GD */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 99 | #if defined(CONFIG_CPU_V7M) |
| 100 | itt lo |
| 101 | #endif |
Simon Glass | aae2aef | 2014-07-10 22:23:26 -0600 | [diff] [blame] | 102 | strlo r0, [r1] /* clear 32-bit GD word */ |
| 103 | addlo r1, r1, #4 /* move to next */ |
| 104 | blo clr_gd |
Simon Glass | ba19599 | 2014-11-10 17:16:44 -0700 | [diff] [blame] | 105 | #if defined(CONFIG_SYS_MALLOC_F_LEN) |
Simon Glass | 76a1e584 | 2014-07-10 22:23:29 -0600 | [diff] [blame] | 106 | sub sp, sp, #CONFIG_SYS_MALLOC_F_LEN |
| 107 | str sp, [r9, #GD_MALLOC_BASE] |
| 108 | #endif |
Simon Glass | aae2aef | 2014-07-10 22:23:26 -0600 | [diff] [blame] | 109 | /* mov r0, #0 not needed due to above code */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 110 | bl board_init_f |
| 111 | |
| 112 | #if ! defined(CONFIG_SPL_BUILD) |
| 113 | |
| 114 | /* |
| 115 | * Set up intermediate environment (new sp and gd) and call |
Benoît Thébaudeau | 5c6db12 | 2013-04-11 09:35:53 +0000 | [diff] [blame] | 116 | * relocate_code(addr_moni). Trick here is that we'll return |
| 117 | * 'here' but relocated. |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 118 | */ |
| 119 | |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 120 | ldr sp, [r9, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 121 | #if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */ |
| 122 | mov r3, sp |
| 123 | bic r3, r3, #7 |
| 124 | mov sp, r3 |
| 125 | #else |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 126 | bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 127 | #endif |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 128 | ldr r9, [r9, #GD_BD] /* r9 = gd->bd */ |
| 129 | sub r9, r9, #GD_SIZE /* new GD is below bd */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 130 | |
| 131 | adr lr, here |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 132 | ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 133 | add lr, lr, r0 |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 134 | #if defined(CONFIG_CPU_V7M) |
| 135 | orr lr, #1 /* As required by Thumb-only */ |
| 136 | #endif |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 137 | ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 138 | b relocate_code |
| 139 | here: |
Albert ARIBAUD | db544b9 | 2014-11-13 17:59:15 +0100 | [diff] [blame] | 140 | /* |
| 141 | * now relocate vectors |
| 142 | */ |
| 143 | |
| 144 | bl relocate_vectors |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 145 | |
| 146 | /* Set up final (full) environment */ |
| 147 | |
| 148 | bl c_runtime_cpu_setup /* we still call old routine here */ |
Simon Glass | db91035 | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 149 | #endif |
| 150 | #if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) |
| 151 | # ifdef CONFIG_SPL_BUILD |
| 152 | /* Use a DRAM stack for the rest of SPL, if requested */ |
| 153 | bl spl_relocate_stack_gd |
| 154 | cmp r0, #0 |
| 155 | movne sp, r0 |
| 156 | # endif |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 157 | ldr r0, =__bss_start /* this is auto-relocated! */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 158 | |
Przemyslaw Marczak | 114c86d | 2015-03-04 14:01:22 +0100 | [diff] [blame] | 159 | #ifdef CONFIG_USE_ARCH_MEMSET |
| 160 | ldr r3, =__bss_end /* this is auto-relocated! */ |
| 161 | mov r1, #0x00000000 /* prepare zero to clear BSS */ |
| 162 | |
| 163 | subs r2, r3, r0 /* r2 = memset len */ |
| 164 | bl memset |
| 165 | #else |
| 166 | ldr r1, =__bss_end /* this is auto-relocated! */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 167 | mov r2, #0x00000000 /* prepare zero to clear BSS */ |
| 168 | |
| 169 | clbss_l:cmp r0, r1 /* while not at end of BSS */ |
rev13@wp.pl | 12d8a72 | 2015-03-01 12:44:39 +0100 | [diff] [blame] | 170 | #if defined(CONFIG_CPU_V7M) |
| 171 | itt lo |
| 172 | #endif |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 173 | strlo r2, [r0] /* clear 32-bit BSS word */ |
| 174 | addlo r0, r0, #4 /* move to next */ |
| 175 | blo clbss_l |
Przemyslaw Marczak | 114c86d | 2015-03-04 14:01:22 +0100 | [diff] [blame] | 176 | #endif |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 177 | |
Simon Glass | db91035 | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 178 | #if ! defined(CONFIG_SPL_BUILD) |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 179 | bl coloured_LED_init |
| 180 | bl red_led_on |
Simon Glass | db91035 | 2015-03-03 08:03:00 -0700 | [diff] [blame] | 181 | #endif |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 182 | /* call board_init_r(gd_t *id, ulong dest_addr) */ |
Jeroen Hofstee | fe1378a | 2013-09-21 14:04:41 +0200 | [diff] [blame] | 183 | mov r0, r9 /* gd_t */ |
| 184 | ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 185 | /* call board_init_r */ |
| 186 | ldr pc, =board_init_r /* this is auto-relocated! */ |
| 187 | |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 188 | /* we should not return here. */ |
Albert ARIBAUD | e05e5de | 2013-01-08 10:18:02 +0000 | [diff] [blame] | 189 | #endif |
Benoît Thébaudeau | 9c5feab | 2013-04-11 09:35:47 +0000 | [diff] [blame] | 190 | |
| 191 | ENDPROC(_main) |