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da94a82930
In August 2012, Matthew Gretton-Dann checked a change into binutils
labelled "Error on obsolete & warn on deprecated registers", apparently as
part of ARMv8 support. Apparently, this was supposed to emit the message
"Warning: This coprocessor register access is deprecated in ARMv8" when
using certain mcr/mrc instructions and building for ARMv8. Unfortunately,
the message that is actually emitted appears to be '(null)', which is
less helpful in comparison.
Even more unfortunately, this is biting us on every single kernel
build with a new gas, because arch/arm/boot/compressed/head.S and some
other files in that directory are built with -march=all since kernel
commit 80cec14a8 "[ARM] Add -march=all to assembly file build in
arch/arm/boot/compressed" back in v2.6.28.
This patch reverts Russell's nice solution and instead marks the head.S
file to be built for armv7-a, which fortunately lets us build all
instructions in that file without warnings even on the broken binutils.
Without this patch, building anything results in:
arch/arm/boot/compressed/head.S: Assembler messages:
arch/arm/boot/compressed/head.S:565: Warning: (null)
arch/arm/boot/compressed/head.S:676: Warning: (null)
arch/arm/boot/compressed/head.S:698: Warning: (null)
arch/arm/boot/compressed/head.S:722: Warning: (null)
arch/arm/boot/compressed/head.S:726: Warning: (null)
arch/arm/boot/compressed/head.S:957: Warning: (null)
arch/arm/boot/compressed/head.S:996: Warning: (null)
arch/arm/boot/compressed/head.S:997: Warning: (null)
arch/arm/boot/compressed/head.S:1027: Warning: (null)
arch/arm/boot/compressed/head.S:1035: Warning: (null)
arch/arm/boot/compressed/head.S:1046: Warning: (null)
arch/arm/boot/compressed/head.S:1060: Warning: (null)
arch/arm/boot/compressed/head.S:1092: Warning: (null)
arch/arm/boot/compressed/head.S:1094: Warning: (null)
arch/arm/boot/compressed/head.S:1095: Warning: (null)
arch/arm/boot/compressed/head.S:1102: Warning: (null)
arch/arm/boot/compressed/head.S:1134: Warning: (null)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Cc: Matthew Gretton-Dann <matthew.gretton-dann@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
49 lines
1.2 KiB
ArmAsm
49 lines
1.2 KiB
ArmAsm
/*
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* linux/arch/arm/boot/compressed/head-sa1100.S
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*
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* Copyright (C) 1999 Nicolas Pitre <nico@fluxnic.net>
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*
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* SA1100 specific tweaks. This is merged into head.S by the linker.
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*
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*/
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#include <linux/linkage.h>
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#include <asm/mach-types.h>
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.section ".start", "ax"
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.arch armv4
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__SA1100_start:
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@ Preserve r8/r7 i.e. kernel entry values
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#ifdef CONFIG_SA1100_COLLIE
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mov r7, #MACH_TYPE_COLLIE
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#endif
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#ifdef CONFIG_SA1100_SIMPAD
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@ UNTIL we've something like an open bootldr
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mov r7, #MACH_TYPE_SIMPAD @should be 87
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#endif
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mrc p15, 0, r0, c1, c0, 0 @ read control reg
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ands r0, r0, #0x0d
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beq 99f
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@ Data cache might be active.
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@ Be sure to flush kernel binary out of the cache,
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@ whatever state it is, before it is turned off.
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@ This is done by fetching through currently executed
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@ memory to be sure we hit the same cache.
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bic r2, pc, #0x1f
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add r3, r2, #0x4000 @ 16 kb is quite enough...
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1: ldr r0, [r2], #32
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teq r2, r3
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bne 1b
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mcr p15, 0, r0, c7, c7, 0 @ flush I & D caches
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@ disabling MMU and caches
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mrc p15, 0, r0, c1, c0, 0 @ read control reg
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bic r0, r0, #0x0d @ clear WB, DC, MMU
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bic r0, r0, #0x1000 @ clear Icache
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mcr p15, 0, r0, c1, c0, 0
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99:
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