Commit 47624248 authored by Russell King's avatar Russell King
Browse files

Merge branch 'xip_zdata' of http://git.linaro.org/people/nicolas.pitre/linux into devel-testing 

This contains important fixes to the XIP linker script, some more linker
script cleanups, .bss clearing and .data copying speedups related to the
above, and an opt-in config option for XIP kernels that allows for
compressing .data in ROM that depend on those other patches to work
properly.
parents 2bd6bf03 ca8b5d97

arch/arm/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -2005,6 +2005,17 @@ config XIP_PHYS_ADDR 
	  be linked for and stored to.  This address is dependent on your

	  own flash usage.



config XIP_DEFLATED_DATA

	bool "Store kernel .data section compressed in ROM"

	depends on XIP_KERNEL

	select ZLIB_INFLATE

	help

	  Before the kernel is actually executed, its .data section has to be

	  copied to RAM from ROM. This option allows for storing that data

	  in compressed form and decompressed to RAM rather than merely being

	  copied, saving some precious ROM space. A possible drawback is a

	  slightly longer boot delay.



config KEXEC

	bool "Kexec system call (EXPERIMENTAL)"

	depends on (!SMP || PM_SLEEP_SMP)

arch/arm/boot/Makefile

+12 −1
Original line number Diff line number Diff line
@@ -31,8 +31,19 @@ targets := Image zImage xipImage bootpImage uImage 


ifeq ($(CONFIG_XIP_KERNEL),y)



cmd_deflate_xip_data = $(CONFIG_SHELL) -c \

	'$(srctree)/$(src)/deflate_xip_data.sh $< $@ || { rm -f $@; false; }'



ifeq ($(CONFIG_XIP_DEFLATED_DATA),y)

quiet_cmd_mkxip = XIPZ    $@

cmd_mkxip = $(cmd_objcopy) && $(cmd_deflate_xip_data)

else

quiet_cmd_mkxip = $(quiet_cmd_objcopy)

cmd_mkxip = $(cmd_objcopy)

endif



$(obj)/xipImage: vmlinux FORCE

	$(call if_changed,objcopy)

	$(call if_changed,mkxip)

	@$(kecho) '  Physical Address of xipImage: $(CONFIG_XIP_PHYS_ADDR)'



$(obj)/Image $(obj)/zImage: FORCE

arch/arm/boot/deflate_xip_data.sh

0 → 100755
+64 −0
Original line number Diff line number Diff line 
#!/bin/sh



# XIP kernel .data segment compressor

#

# Created by:	Nicolas Pitre, August 2017

# Copyright:	(C) 2017  Linaro Limited

#

# 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.



# This script locates the start of the .data section in xipImage and

# substitutes it with a compressed version. The needed offsets are obtained

# from symbol addresses in vmlinux. It is expected that .data extends to

# the end of xipImage.



set -e



VMLINUX="$1"

XIPIMAGE="$2"



DD="dd status=none"



# Use "make V=1" to debug this script.

case "$KBUILD_VERBOSE" in

*1*)

	set -x

	;;

esac



sym_val() {

	# extract hex value for symbol in $1

	local val=$($NM "$VMLINUX" | sed -n "/ $1$/{s/ .*$//p;q}")

	[ "$val" ] || { echo "can't find $1 in $VMLINUX" 1>&2; exit 1; }

	# convert from hex to decimal

	echo $((0x$val))

}



__data_loc=$(sym_val __data_loc)

_edata_loc=$(sym_val _edata_loc)

base_offset=$(sym_val _xiprom)



# convert to file based offsets

data_start=$(($__data_loc - $base_offset))

data_end=$(($_edata_loc - $base_offset))



# Make sure data occupies the last part of the file.

file_end=$(stat -c "%s" "$XIPIMAGE")

if [ "$file_end" != "$data_end" ]; then

	printf "end of xipImage doesn't match with _edata_loc (%#x vs %#x)\n" \

	       $(($file_end + $base_offset)) $_edata_loc 2>&1

	exit 1;

fi



# be ready to clean up

trap 'rm -f "$XIPIMAGE.tmp"' 0 1 2 3



# substitute the data section by a compressed version

$DD if="$XIPIMAGE" count=$data_start iflag=count_bytes of="$XIPIMAGE.tmp"

$DD if="$XIPIMAGE"  skip=$data_start iflag=skip_bytes |

gzip -9 >> "$XIPIMAGE.tmp"



# replace kernel binary

mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"

arch/arm/kernel/Makefile

+5 −0
Original line number Diff line number Diff line
@@ -87,6 +87,11 @@ head-y := head$(MMUEXT).o 
obj-$(CONFIG_DEBUG_LL)	+= debug.o

obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o



# This is executed very early using a temporary stack when no memory allocator

# nor global data is available. Everything has to be allocated on the stack.

CFLAGS_head-inflate-data.o := $(call cc-option,-Wframe-larger-than=10240)

obj-$(CONFIG_XIP_DEFLATED_DATA) += head-inflate-data.o



obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o

AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a

ifeq ($(CONFIG_ARM_PSCI),y)

arch/arm/kernel/head-common.S

+53 −32
Original line number Diff line number Diff line
@@ -79,47 +79,68 @@ ENDPROC(__vet_atags) 
 */

	__INIT

__mmap_switched:

	adr	r3, __mmap_switched_data



	ldmia	r3!, {r4, r5, r6, r7}

	cmp	r4, r5				@ Copy data segment if needed

1:	cmpne	r5, r6

	ldrne	fp, [r4], #4

	strne	fp, [r5], #4

	bne	1b



	mov	fp, #0				@ Clear BSS (and zero fp)

1:	cmp	r6, r7

	strcc	fp, [r6],#4

	bcc	1b



 ARM(	ldmia	r3, {r4, r5, r6, r7, sp})

 THUMB(	ldmia	r3, {r4, r5, r6, r7}	)

 THUMB(	ldr	sp, [r3, #16]		)

	str	r9, [r4]			@ Save processor ID

	str	r1, [r5]			@ Save machine type

	str	r2, [r6]			@ Save atags pointer

	cmp	r7, #0

	strne	r0, [r7]			@ Save control register values



	mov	r7, r1

	mov	r8, r2

	mov	r10, r0



	adr	r4, __mmap_switched_data

	mov	fp, #0



#if defined(CONFIG_XIP_DEFLATED_DATA)

   ARM(	ldr	sp, [r4], #4 )

 THUMB(	ldr	sp, [r4] )

 THUMB(	add	r4, #4 )

	bl	__inflate_kernel_data		@ decompress .data to RAM

	teq	r0, #0

	bne	__error

#elif defined(CONFIG_XIP_KERNEL)

   ARM(	ldmia	r4!, {r0, r1, r2, sp} )

 THUMB(	ldmia	r4!, {r0, r1, r2, r3} )

 THUMB(	mov	sp, r3 )

	sub	r2, r2, r1

	bl	memcpy				@ copy .data to RAM

#endif



   ARM(	ldmia	r4!, {r0, r1, sp} )

 THUMB(	ldmia	r4!, {r0, r1, r3} )

 THUMB(	mov	sp, r3 )

	sub	r1, r1, r0

	bl	__memzero			@ clear .bss



	ldmia	r4, {r0, r1, r2, r3}

	str	r9, [r0]			@ Save processor ID

	str	r7, [r1]			@ Save machine type

	str	r8, [r2]			@ Save atags pointer

	cmp	r3, #0

	strne	r10, [r3]			@ Save control register values

	b	start_kernel

ENDPROC(__mmap_switched)



	.align	2

	.type	__mmap_switched_data, %object

__mmap_switched_data:

	.long	__data_loc			@ r4

	.long	_sdata				@ r5

	.long	__bss_start			@ r6

	.long	_end				@ r7

	.long	processor_id			@ r4

	.long	__machine_arch_type		@ r5

	.long	__atags_pointer			@ r6

#ifdef CONFIG_XIP_KERNEL

#ifndef CONFIG_XIP_DEFLATED_DATA

	.long	_sdata				@ r0

	.long	__data_loc			@ r1

	.long	_edata_loc			@ r2

#endif

	.long	__bss_stop			@ sp (temporary stack in .bss)

#endif



	.long	__bss_start			@ r0

	.long	__bss_stop			@ r1

	.long	init_thread_union + THREAD_START_SP @ sp



	.long	processor_id			@ r0

	.long	__machine_arch_type		@ r1

	.long	__atags_pointer			@ r2

#ifdef CONFIG_CPU_CP15

	.long	cr_alignment			@ r7

	.long	cr_alignment			@ r3

#else

	.long	0				@ r7

	.long	0				@ r3

#endif

	.long	init_thread_union + THREAD_START_SP @ sp

	.size	__mmap_switched_data, . - __mmap_switched_data



/*