From e69edc7939abda1f696c482faa8168d80420f75c Mon Sep 17 00:00:00 2001 From: Eric Miao Date: Mon, 5 Jul 2010 15:56:50 +0200 Subject: ARM: Auto calculate ZRELADDR and provide option for exceptions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As long as the zImage is placed within the 128MB range from the start of memory, ZRELADDR (Address where the decompressed kernel will be placed, usually == PHYS_OFFSET + TEXT_OFFSET) can be determined at run-time by masking PC with 0xf80000000. Running through all the Makefile.boot, all those zreladdr-y addresses == 0x[0-f][08]00_0000 + TEXT_OFFSET can be determined at run-time. Option CONFIG_AUTO_ZRELADDR and CONFIG_ZRELADDR are introduced, CONFIG_ZRELADDR _must_ be explicitly specified if: - ((zreladdr-y - TEXT_OFFSET) & ~0xf8000000) != 0, which means masking PC with 0xf8000000 will result in an incorrect address. Currently this is only a problem on u300. - or the assumption of the zImage being loaded by the bootloader within the first 128MB of RAM is incorrect - or when ZBOOT_ROM is used, where the above assumption is usually wrong. [ukleinek: changed mask from 0xf0000000 to 0xf8000000 for mx1 and shark + some review fixes from the mailing list] Original-Idea-and-Signed-off-by: Nicolas Pitre Signed-off-by: Eric Miao Signed-off-by: Uwe Kleine-König --- arch/arm/boot/compressed/head.S | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/arm/boot/compressed/head.S') diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index d27faa13179..abf4d65acf6 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -170,9 +170,16 @@ not_angel: .text adr r0, LC0 - ARM( ldmia r0, {r1, r2, r3, r4, r5, r6, r11, ip, sp}) - THUMB( ldmia r0, {r1, r2, r3, r4, r5, r6, r11, ip} ) + ARM( ldmia r0, {r1, r2, r3, r5, r6, r11, ip, sp}) + THUMB( ldmia r0, {r1, r2, r3, r5, r6, r11, ip} ) THUMB( ldr sp, [r0, #32] ) +#ifdef CONFIG_AUTO_ZRELADDR + @ determine final kernel image address + and r4, pc, #0xf8000000 + add r4, r4, #TEXT_OFFSET +#else + ldr r4, =CONFIG_ZRELADDR +#endif subs r0, r0, r1 @ calculate the delta offset @ if delta is zero, we are @@ -310,7 +317,6 @@ wont_overwrite: mov r0, r4 LC0: .word LC0 @ r1 .word __bss_start @ r2 .word _end @ r3 - .word zreladdr @ r4 .word _start @ r5 .word _image_size @ r6 .word _got_start @ r11 -- cgit v1.2.3-18-g5258