+/* 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>
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <asm-offsets.h>
#include <linux/linkage.h>
-#ifdef CONFIG_CPU_V7M
-#include <asm/armv7m.h>
-#endif
+#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
-#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */
- mov r3, sp
- bic r3, r3, #7
- mov sp, r3
-#else
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
+ 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 r2, sp
- sub sp, sp, #GD_SIZE /* allocate one GD above SP */
-#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */
- mov r3, sp
- bic r3, r3, #7
- mov sp, r3
-#else
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
-#endif
- mov r9, sp /* GD is above SP */
- mov r1, sp
+
mov r0, #0
-clr_gd:
- cmp r1, r2 /* while not at end of GD */
-#if defined(CONFIG_CPU_V7M)
- itt lo
-#endif
- strlo r0, [r1] /* clear 32-bit GD word */
- addlo r1, r1, #4 /* move to next */
- blo clr_gd
-#if defined(CONFIG_SYS_MALLOC_F_LEN)
- sub sp, sp, #CONFIG_SYS_MALLOC_F_LEN
- str sp, [r9, #GD_MALLOC_BASE]
-#endif
- /* mov r0, #0 not needed due to above code */
bl board_init_f
#if ! defined(CONFIG_SPL_BUILD)
* 'here' but relocated.
*/
- ldr sp, [r9, #GD_START_ADDR_SP] /* sp = gd->start_addr_sp */
-#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */
- mov r3, sp
- bic r3, r3, #7
- mov sp, r3
-#else
- bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
-#endif
+ 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 */
bl c_runtime_cpu_setup /* we still call old routine here */
#endif
-#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK)
+#if !defined(CONFIG_SPL_BUILD) || CONFIG_IS_ENABLED(FRAMEWORK)
+
+#if !defined(CONFIG_SPL_EARLY_BSS)
+ SPL_CLEAR_BSS
+#endif
+
# 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
- 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 */
-#if defined(CONFIG_CPU_V7M)
- itt lo
-#endif
- strlo r2, [r0] /* clear 32-bit BSS word */
- addlo r0, r0, #4 /* move to next */
- blo clbss_l
-#endif
#if ! defined(CONFIG_SPL_BUILD)
bl coloured_LED_init
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
projects / oweals / u-boot.git / blobdiff