unicore32 additional architecture files: boot process

This patch implements booting process, including uncompression process.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/unicore32/boot/Makefile

@@ -0,0 +1,47 @@
+#
+# arch/unicore32/boot/Makefile
+#
+# This file is included by the global makefile so that you can add your own
+# architecture-specific flags and dependencies.
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 2001~2010 GUAN Xue-tao
+#
+
+MKIMAGE := $(srctree)/scripts/mkuboot.sh
+
+targets := Image zImage uImage
+
+$(obj)/Image: vmlinux FORCE
+	$(call if_changed,objcopy)
+	@echo '  Kernel: $@ is ready'
+
+$(obj)/compressed/vmlinux: $(obj)/Image FORCE
+	$(Q)$(MAKE) $(build)=$(obj)/compressed $@
+
+$(obj)/zImage: $(obj)/compressed/vmlinux FORCE
+	$(call if_changed,objcopy)
+	@echo '  Kernel: $@ is ready'
+
+quiet_cmd_uimage = UIMAGE  $@
+      cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A unicore -O linux -T kernel \
+		   -C none -a $(LOADADDR) -e $(STARTADDR) \
+		   -n 'Linux-$(KERNELRELEASE)' -d $< $@
+
+$(obj)/uImage: LOADADDR=0x0
+
+$(obj)/uImage: STARTADDR=$(LOADADDR)
+
+$(obj)/uImage: $(obj)/zImage FORCE
+	$(call if_changed,uimage)
+	@echo '  Image $@ is ready'
+
+PHONY += initrd FORCE
+initrd:
+	@test "$(INITRD)" != "" || \
+	(echo You must specify INITRD; exit -1)
+
+subdir- := compressed

arch/unicore32/boot/compressed/Makefile

@@ -0,0 +1,68 @@
+#
+# linux/arch/unicore32/boot/compressed/Makefile
+#
+# create a compressed vmlinuz image from the original vmlinux
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 2001~2010 GUAN Xue-tao
+#
+
+EXTRA_CFLAGS	:= -fpic -fno-builtin
+EXTRA_AFLAGS	:= -Wa,-march=all
+
+OBJS		:= misc.o
+
+# font.c and font.o
+CFLAGS_font.o	:= -Dstatic=
+$(obj)/font.c: $(srctree)/drivers/video/console/font_8x8.c
+	$(call cmd,shipped)
+
+# piggy.S and piggy.o
+suffix_$(CONFIG_KERNEL_GZIP)	:= gzip
+suffix_$(CONFIG_KERNEL_BZIP2)	:= bz2
+suffix_$(CONFIG_KERNEL_LZO)	:= lzo
+suffix_$(CONFIG_KERNEL_LZMA)	:= lzma
+
+$(obj)/piggy.$(suffix_y): $(obj)/../Image FORCE
+	$(call if_changed,$(suffix_y))
+
+SEDFLAGS_piggy	= s/DECOMP_SUFFIX/$(suffix_y)/
+$(obj)/piggy.S: $(obj)/piggy.S.in
+	@sed "$(SEDFLAGS_piggy)" < $< > $@
+
+$(obj)/piggy.o:  $(obj)/piggy.$(suffix_y) $(obj)/piggy.S FORCE
+
+targets		:= vmlinux vmlinux.lds font.o font.c head.o misc.o \
+			piggy.$(suffix_y) piggy.o piggy.S \
+
+# Make sure files are removed during clean
+extra-y		+= piggy.gzip piggy.bz2 piggy.lzo piggy.lzma
+
+# ?
+LDFLAGS_vmlinux += -p
+# Report unresolved symbol references
+LDFLAGS_vmlinux += --no-undefined
+# Delete all temporary local symbols
+LDFLAGS_vmlinux += -X
+# Next argument is a linker script
+LDFLAGS_vmlinux += -T
+
+# For uidivmod
+$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/head.o $(obj)/piggy.o \
+		$(obj)/misc.o FORCE
+	$(call if_changed,ld)
+	@:
+
+# We now have a PIC decompressor implementation.  Decompressors running
+# from RAM should not define ZTEXTADDR.  Decompressors running directly
+# from ROM or Flash must define ZTEXTADDR (preferably via the config)
+ZTEXTADDR	:= 0
+ZBSSADDR	:= ALIGN(4)
+
+SEDFLAGS_lds	= s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/
+$(obj)/vmlinux.lds: $(obj)/vmlinux.lds.in arch/unicore32/boot/Makefile $(KCONFIG_CONFIG)
+	@sed "$(SEDFLAGS_lds)" < $< > $@
+

arch/unicore32/boot/compressed/head.S

@@ -0,0 +1,204 @@
+/*
+ * linux/arch/unicore32/boot/compressed/head.S
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <mach/memory.h>
+
+#define csub	cmpsub
+#define cand	cmpand
+#define nop8	nop; nop; nop; nop; nop; nop; nop; nop
+
+		.section ".start", #alloc, #execinstr
+		.text
+start:
+		.type	start,#function
+
+		/* Initialize ASR, PRIV mode and INTR off */
+		mov	r0, #0xD3
+		mov.a	asr, r0
+
+		adr	r0, LC0
+		ldm	(r1, r2, r3, r5, r6, r7, r8), [r0]+
+		ldw	sp, [r0+], #28
+		sub.a	r0, r0, r1		@ calculate the delta offset
+
+		/*
+		 * if delta is zero, we are running at the address
+		 * we were linked at.
+		 */
+		beq	not_relocated
+
+		/*
+		 * We're running at a different address.  We need to fix
+		 * up various pointers:
+		 *   r5 - zImage base address (_start)
+		 *   r7 - GOT start
+		 *   r8 - GOT end
+		 */
+		add	r5, r5, r0
+		add	r7, r7, r0
+		add	r8, r8, r0
+
+		/*
+		 * we need to fix up pointers into the BSS region.
+		 *   r2 - BSS start
+		 *   r3 - BSS end
+		 *   sp - stack pointer
+		 */
+		add	r2, r2, r0
+		add	r3, r3, r0
+		add	sp, sp, r0
+
+		/*
+		 * Relocate all entries in the GOT table.
+		 * This fixes up the C references.
+		 *   r7 - GOT start
+		 *   r8 - GOT end
+		 */
+1001:		ldw	r1, [r7+], #0
+		add	r1, r1, r0
+		stw.w	r1, [r7]+, #4
+		csub.a	r7, r8
+		bub	1001b
+
+not_relocated:
+		/*
+		 * Clear BSS region.
+		 *   r2 - BSS start
+		 *   r3 - BSS end
+		 */
+		mov	r0, #0
+1002:		stw.w	r0, [r2]+, #4
+		csub.a	r2, r3
+		bub	1002b
+
+		/*
+		 * Turn on the cache.
+		 */
+                mov     r0, #0
+                movc    p0.c5, r0, #28		@ cache invalidate all
+                nop8
+                movc    p0.c6, r0, #6		@ tlb invalidate all
+                nop8
+
+                mov     r0, #0x1c		@ en icache and wb dcache
+                movc    p0.c1, r0, #0
+                nop8
+
+		/*
+		 * Set up some pointers, for starting decompressing.
+		 */
+
+		mov	r1, sp			@ malloc space above stack
+		add	r2, sp, #0x10000	@ 64k max
+
+		/*
+		 * Check to see if we will overwrite ourselves.
+		 *   r4 = final kernel address
+		 *   r5 = start of this image
+		 *   r6 = size of decompressed image
+		 *   r2 = end of malloc space (and therefore this image)
+		 * We basically want:
+		 *   r4 >= r2 -> OK
+		 *   r4 + image length <= r5 -> OK
+		 */
+		ldw	r4, =KERNEL_IMAGE_START
+		csub.a	r4, r2
+		bea	wont_overwrite
+		add	r0, r4, r6
+		csub.a	r0, r5
+		beb	wont_overwrite
+
+		/*
+		 * If overwrite, just print error message
+		 */
+		b	__error_overwrite
+
+		/*
+		 * We're not in danger of overwriting ourselves.
+		 * Do this the simple way.
+		 */
+wont_overwrite:
+		/*
+		 * decompress_kernel:
+		 *   r0: output_start
+		 *   r1: free_mem_ptr_p
+		 *   r2: free_mem_ptr_end_p
+		 */
+		mov	r0, r4
+		b.l	decompress_kernel	@ C functions
+
+		/*
+		 * Clean and flush the cache to maintain consistency.
+		 */
+		mov	r0, #0
+                movc    p0.c5, r0, #14		@ flush dcache
+		nop8
+                movc    p0.c5, r0, #20		@ icache invalidate all
+                nop8
+
+		/*
+		 * Turn off the Cache and MMU.
+		 */
+		mov	r0, #0			@ disable i/d cache and MMU
+		movc	p0.c1, r0, #0
+                nop8
+
+		mov	r0, #0			@ must be zero
+		ldw	r4, =KERNEL_IMAGE_START
+		mov	pc, r4			@ call kernel
+
+
+		.align	2
+		.type	LC0, #object
+LC0:		.word	LC0			@ r1
+		.word	__bss_start		@ r2
+		.word	_end			@ r3
+		.word	_start			@ r5
+		.word	_image_size		@ r6
+		.word	_got_start		@ r7
+		.word	_got_end		@ r8
+		.word	decompress_stack_end	@ sp
+		.size	LC0, . - LC0
+
+print_string:
+#ifdef CONFIG_DEBUG_OCD
+2001:		ldb.w	r1, [r0]+, #1
+		csub.a	r1, #0
+		bne	2002f
+		mov	pc, lr
+2002:
+		movc	r2, p1.c0, #0
+		cand.a	r2, #2
+		bne	2002b
+		movc	p1.c1, r1, #1
+		csub.a	r1, #'\n'
+		cmoveq	r1, #'\r'
+		beq	2002b
+		b	2001b
+#else
+		mov	pc, lr
+#endif
+
+__error_overwrite:
+		adr	r0, str_error
+		b.l	print_string
+2001:		nop8
+		b	2001b
+str_error:	.asciz	"\nError: Kernel address OVERWRITE\n"
+		.align
+
+		.ltorg
+
+		.align	4
+		.section ".stack", "aw", %nobits
+decompress_stack:	.space	4096
+decompress_stack_end: