Commit f1f012b0 authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

ARM: decompressor: defer loading of the contents of the LC0 structure 



The remaining contents of LC0 are only used after the point in the
decompressor startup code where we enter via 'wont_overwrite'. So
move the loading of the LC0 structure after it. This will allow us
to jump to wont_overwrite directly from the EFI stub, and execute
the decompressor in place at the offset it was loaded by the UEFI
firmware.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarNicolas Pitre <nico@fluxnic.net>
parent 161e04a5

arch/arm/boot/compressed/head.S

+4 −11
Original line number Diff line number Diff line
@@ -299,10 +299,6 @@ restart: adr r0, LC1 
		add	sp, sp, r0

		add	r6, r6, r0



		adr	r0, LC0

		ldmia	r0, {r1, r2, r3, r11, r12}

		sub	r0, r0, r1		@ calculate the delta offset



		get_inflated_image_size	r9, r10, lr



#ifndef CONFIG_ZBOOT_ROM
@@ -320,9 +316,6 @@ restart: adr r0, LC1 
		mov	r5, #0			@ init dtb size to 0

#ifdef CONFIG_ARM_APPENDED_DTB

/*

 *   r0  = delta

 *   r2  = BSS start

 *   r3  = BSS end

 *   r4  = final kernel address (possibly with LSB set)

 *   r5  = appended dtb size (still unknown)

 *   r6  = _edata
@@ -330,8 +323,6 @@ restart: adr r0, LC1 
 *   r8  = atags/device tree pointer

 *   r9  = size of decompressed image

 *   r10 = end of this image, including  bss/stack/malloc space if non XIP

 *   r11 = GOT start

 *   r12 = GOT end

 *   sp  = stack pointer

 *

 * if there are device trees (dtb) appended to zImage, advance r10 so that the
@@ -379,7 +370,6 @@ restart: adr r0, LC1 
		/* temporarily relocate the stack past the DTB work space */

		add	sp, sp, r5



		stmfd	sp!, {r0-r3, ip, lr}

		mov	r0, r8

		mov	r1, r6

		mov	r2, r5
@@ -398,7 +388,6 @@ restart: adr r0, LC1 
		mov	r2, r5

		bleq	atags_to_fdt



		ldmfd	sp!, {r0-r3, ip, lr}

		sub	sp, sp, r5

#endif
@@ -535,6 +524,10 @@ dtb_check_done: 
		mov	pc, r0



wont_overwrite:

		adr	r0, LC0

		ldmia	r0, {r1, r2, r3, r11, r12}

		sub	r0, r0, r1		@ calculate the delta offset



/*

 * If delta is zero, we are running at the address we were linked at.

 *   r0  = delta

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