+/* SPDX-License-Identifier: GPL-2.0+ */
/*
* crt0 - C-runtime startup Code for ARM U-Boot
*
* Copyright (c) 2012 Albert ARIBAUD <albert.u.boot@aribaud.net>
- *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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.
- *
- * 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.
- *
- * 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
*/
#include <config.h>
#include <asm-offsets.h>
#include <linux/linkage.h>
+#include <asm/assembler.h>
/*
* This file handles the target-independent stages of the U-Boot
* the GD ('global data') structure, both located in some readily
* available RAM (SRAM, locked cache...). In this context, VARIABLE
* global data, initialized or not (BSS), are UNAVAILABLE; only
- * CONSTANT initialized data are available.
+ * CONSTANT initialized data are available. GD should be zeroed
+ * before board_init_f() is called.
*
* 2. Call board_init_f(). This function prepares the hardware for
* execution from system RAM (DRAM, DDR...) As system RAM may not
* data include the relocation destination, the future stack, and
* the future GD location.
*
- * (the following applies only to non-SPL builds)
- *
* 3. Set up intermediate environment where the stack and GD are the
* ones allocated by board_init_f() in system RAM, but BSS and
* initialized non-const data are still not available.
*
- * 4. Call relocate_code(). This function relocates U-Boot from its
- * current location into the relocation destination computed by
- * board_init_f().
+ * 4a.For U-Boot proper (not SPL), call relocate_code(). This function
+ * relocates U-Boot from its current location into the relocation
+ * destination computed by board_init_f().
+ *
+ * 4b.For SPL, board_init_f() just returns (to crt0). There is no
+ * code relocation in SPL.
*
* 5. Set up final environment for calling board_init_r(). This
* environment has BSS (initialized to 0), initialized non-const
* data (initialized to their intended value), and stack in system
- * RAM. GD has retained values set by board_init_f(). Some CPUs
- * have some work left to do at this point regarding memory, so
- * call c_runtime_cpu_setup.
+ * RAM (for SPL moving the stack and GD into RAM is optional - see
+ * CONFIG_SPL_STACK_R). GD has retained values set by board_init_f().
*
- * 6. Branch to board_init_r().
+ * 6. For U-Boot proper (not SPL), some CPUs have some work left to do
+ * at this point regarding memory, so call c_runtime_cpu_setup.
+ *
+ * 7. Branch to board_init_r().
+ *
+ * For more information see 'Board Initialisation Flow in README.
+ */
+
+/*
+ * Macro for clearing BSS during SPL execution. Usually called during the
+ * relocation process for most boards before entering board_init_r(), but
+ * can also be done early before entering board_init_f() on plaforms that
+ * can afford it due to sufficient memory being available early.
*/
+.macro SPL_CLEAR_BSS
+ ldr r0, =__bss_start /* this is auto-relocated! */
+
+#ifdef CONFIG_USE_ARCH_MEMSET
+ ldr r3, =__bss_end /* this is auto-relocated! */
+ mov r1, #0x00000000 /* prepare zero to clear BSS */
+
+ subs r2, r3, r0 /* r2 = memset len */
+ bl memset
+#else
+ ldr r1, =__bss_end /* this is auto-relocated! */
+ mov r2, #0x00000000 /* prepare zero to clear BSS */
+
+clbss_l:cmp r0, r1 /* while not at end of BSS */
+ strlo r2, [r0] /* clear 32-bit BSS word */
+ addlo r0, r0, #4 /* move to next */
+ blo clbss_l
+#endif
+.endm
+
/*
* entry point of crt0 sequence
*/
* Set up initial C runtime environment and call board_init_f(0).
*/
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
- ldr sp, =(CONFIG_SPL_STACK)
+#if defined(CONFIG_TPL_BUILD) && defined(CONFIG_TPL_NEEDS_SEPARATE_STACK)
+ ldr r0, =(CONFIG_TPL_STACK)
+#elif defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
+ ldr r0, =(CONFIG_SPL_STACK)
#else
- ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
+ ldr r0, =(CONFIG_SYS_INIT_SP_ADDR)
#endif
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
- sub sp, #GD_SIZE /* allocate one GD above SP */
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
- mov r8, sp /* GD is above SP */
+ bic r0, r0, #7 /* 8-byte alignment for ABI compliance */
+ mov sp, r0
+ bl board_init_f_alloc_reserve
+ mov sp, r0
+ /* set up gd here, outside any C code */
+ mov r9, r0
+ bl board_init_f_init_reserve
+
+#if defined(CONFIG_SPL_EARLY_BSS)
+ SPL_CLEAR_BSS
+#endif
+
mov r0, #0
bl board_init_f
* 'here' but relocated.
*/
- ldr sp, [r8, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
- ldr r8, [r8, #GD_BD] /* r8 = gd->bd */
- sub r8, r8, #GD_SIZE /* new GD is below bd */
+ ldr r0, [r9, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */
+ bic r0, r0, #7 /* 8-byte alignment for ABI compliance */
+ mov sp, r0
+ ldr r9, [r9, #GD_BD] /* r9 = gd->bd */
+ sub r9, r9, #GD_SIZE /* new GD is below bd */
adr lr, here
- ldr r0, [r8, #GD_RELOC_OFF] /* r0 = gd->reloc_off */
+ ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */
add lr, lr, r0
- ldr r0, [r8, #GD_RELOCADDR] /* r0 = gd->relocaddr */
+#if defined(CONFIG_CPU_V7M)
+ orr lr, #1 /* As required by Thumb-only */
+#endif
+ ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */
b relocate_code
here:
+/*
+ * now relocate vectors
+ */
+
+ bl relocate_vectors
/* Set up final (full) environment */
bl c_runtime_cpu_setup /* we still call old routine here */
+#endif
+#if !defined(CONFIG_SPL_BUILD) || CONFIG_IS_ENABLED(FRAMEWORK)
- ldr r0, =__bss_start /* this is auto-relocated! */
- ldr r1, =__bss_end /* this is auto-relocated! */
+#if !defined(CONFIG_SPL_EARLY_BSS)
+ SPL_CLEAR_BSS
+#endif
- mov r2, #0x00000000 /* prepare zero to clear BSS */
-
-clbss_l:cmp r0, r1 /* while not at end of BSS */
- strlo r2, [r0] /* clear 32-bit BSS word */
- addlo r0, r0, #4 /* move to next */
- blo clbss_l
+# ifdef CONFIG_SPL_BUILD
+ /* Use a DRAM stack for the rest of SPL, if requested */
+ bl spl_relocate_stack_gd
+ cmp r0, #0
+ movne sp, r0
+ movne r9, r0
+# endif
+#if ! defined(CONFIG_SPL_BUILD)
bl coloured_LED_init
bl red_led_on
-
+#endif
/* call board_init_r(gd_t *id, ulong dest_addr) */
- mov r0, r8 /* gd_t */
- ldr r1, [r8, #GD_RELOCADDR] /* dest_addr */
+ mov r0, r9 /* gd_t */
+ ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */
/* call board_init_r */
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
+ ldr lr, =board_init_r /* this is auto-relocated! */
+ bx lr
+#else
ldr pc, =board_init_r /* this is auto-relocated! */
-
+#endif
/* we should not return here. */
-
#endif
ENDPROC(_main)
projects / oweals / u-boot.git / blobdiff