sh: share the correct version of start.S among all cpus

It is easy to note that SH2/SH3/SH4 start.S code is practically
the same with a minor difference for SH2 where a short data header is
present. To avoid unwanted code duplication and to automatically
convert SH2 and SH3 platforms to generic board support move fixed SH4
start.S into arch/sh/lib/start.S and share it among all platforms.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sh/Makefile

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-head-y := arch/sh/cpu/$(CPU)/start.o
+head-y := arch/sh/lib/start.o
 
 libs-y += arch/sh/cpu/$(CPU)/
 libs-y += arch/sh/lib/

arch/sh/cpu/sh2/Makefile

@@ -8,5 +8,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-extra-y	= start.o
 obj-y	= cpu.o interrupts.o watchdog.o

arch/sh/cpu/sh2/start.S

-/*
- * Copyright (C) 2007,2008 Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
- * Copyright (C) 2008 Renesas Solutions Corp.
-
- * SPDX-License-Identifier:	GPL-2.0+
- */
-
-#include <asm-offsets.h>
-#include <config.h>
-
-	.text
-	.align	2
-
-	.global	_start
-_sh_start:
-	.long 0x00000010	/* Ppower ON reset PC*/
-	.long 0x00000000
-	.long 0x00000010	/* Manual reset PC */
-	.long 0x00000000
-_init:
-	mov.l	._lowlevel_init, r0
-100:	bsrf	r0
-	nop
-	bsr	1f
-	nop
-1:	sts	pr, r5
-	mov.l	._reloc_dst, r4
-	add	#(_sh_start-1b), r5
-	mov.l	._reloc_dst_end, r6
-
-2:	mov.l	@r5+, r1
-	mov.l	r1, @r4
-	add	#4, r4
-	cmp/hs	r6, r4
-	bf	2b
-
-	mov.l	._bss_start, r4
-	mov.l	._bss_end, r5
-	mov	#0, r1
-
-3:	mov.l	r1, @r4			/* bss clear */
-	add	#4, r4
-	cmp/hs	r5, r4
-	bf	3b
-
-	mov.l	._gd_init, r13		/* global data */
-	mov.l	._stack_init, r15	/* stack */
-
-	#TODO(sh maintainer): Fix this up to call the correct code
-	#mov.l	._sh_generic_init, r0
-	#jsr	@r0
-	nop
-
-loop:
-	bra	loop
-
-	.align	2
-
-._lowlevel_init:	.long	(lowlevel_init - (100b + 4))
-._reloc_dst:		.long	reloc_dst
-._reloc_dst_end:	.long	reloc_dst_end
-._bss_start:		.long	bss_start
-._bss_end:		.long	bss_end
-._gd_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE)
-._stack_init:	.long	(_sh_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
-#._sh_generic_init:	.long	sh_generic_init

arch/sh/cpu/sh3/Makefile

@@ -11,5 +11,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-extra-y	= start.o
 obj-y	= cpu.o interrupts.o watchdog.o

arch/sh/cpu/sh3/start.S

-/*
- * (C) Copyright 2007
- * Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
- *
- * (C) Copyright 2007
- * Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
- *
- * SPDX-License-Identifier:	GPL-2.0+
- */
-
-#include <asm-offsets.h>
-#include <config.h>
-
-	.text
-	.align	2
-
-	.global	_start
-_sh_start:
-	mov.l	._lowlevel_init, r0
-100:	bsrf	r0
-	nop
-
-	bsr	1f
-	nop
-1:	sts	pr, r5
-	mov.l	._reloc_dst, r4
-	add	#(_sh_start-1b), r5
-	mov.l	._reloc_dst_end, r6
-
-2:	mov.l	@r5+, r1
-	mov.l	r1, @r4
-	add	#4, r4
-	cmp/hs	r6, r4
-	bf	2b
-
-	mov.l	._bss_start, r4
-	mov.l	._bss_end, r5
-	mov	#0, r1
-
-3:	mov.l	r1, @r4			/* bss clear */
-	add	#4, r4
-	cmp/hs	r5, r4
-	bf	3b
-
-	mov.l	._gd_init, r13		/* global data */
-	mov.l	._stack_init, r15	/* stack */
-
-	#TODO(sh maintainer): Fix this up to call the correct code
-	#mov.l	._sh_generic_init, r0
-	#jsr	@r0
-	nop
-
-loop:
-	bra	loop
-
-	.align	2
-
-._lowlevel_init:	.long	(lowlevel_init - (100b + 4))
-._reloc_dst:		.long	reloc_dst
-._reloc_dst_end:	.long	reloc_dst_end
-._bss_start:		.long	bss_start
-._bss_end:		.long	bss_end
-._gd_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE)
-._stack_init:	.long	(_sh_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
-#._sh_generic_init:	.long	sh_generic_init

arch/sh/cpu/sh4/Makefile

@@ -8,5 +8,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-extra-y	= start.o
 obj-y	= cpu.o interrupts.o watchdog.o cache.o

arch/sh/lib/Makefile

@@ -5,6 +5,8 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+extra-y	+= start.o
+
 obj-y	+= board.o
 obj-$(CONFIG_CMD_BOOTM) += bootm.o
 ifeq ($(CONFIG_CPU_SH2),y)

arch/sh/cpu/sh4/start.S → arch/sh/lib/start.S

@@ -13,6 +13,12 @@
 
 	.global	_start
 _start:
+#ifdef CONFIG_CPU_SH2
+	.long 0x00000010        /* Ppower ON reset PC*/
+	.long 0x00000000
+	.long 0x00000010        /* Manual reset PC */
+	.long 0x00000000
+#endif
 	mov.l	._lowlevel_init, r0
 100:	bsrf	r0
 	nop