X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;ds=sidebyside;f=arch%2Farm%2Flib%2Fcrt0.S;h=0decce2c5b25e2292a48f34e6b14aebc8d5e0502;hb=3f484226793166c75bd56784832d4c1a84061ad5;hp=afd4f102dc87d4c0bcc5d9f2198f121d66f9f62f;hpb=5f757cdcc6efbefec09b8f964a234f84ff9fa7f6;p=u-boot

diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index afd4f102dc..0decce2c5b 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -1,9 +1,8 @@
+/* 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>
@@ -25,7 +24,8 @@
  *    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
@@ -34,24 +34,29 @@
  *    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. 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().
  *
- * 6. Branch to board_init_r().
+ * For more information see 'Board Initialisation Flow in README.
  */
 
 /*
@@ -65,42 +70,19 @@ ENTRY(_main)
  */
 
 #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
-	ldr	sp, =(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 */
-#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
+	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
+
 	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)
@@ -111,14 +93,9 @@ clr_gd:
  * '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 */
 
@@ -147,6 +124,7 @@ here:
 	bl	spl_relocate_stack_gd
 	cmp	r0, #0
 	movne	sp, r0
+	movne	r9, r0
 # endif
 	ldr	r0, =__bss_start	/* this is auto-relocated! */
 
@@ -177,8 +155,12 @@ clbss_l:cmp	r0, r1			/* while not at end of BSS */
 	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