Commit 5d6f5267 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

ARM: rework endianess selection 



Choosing big-endian vs little-endian kernels in Kconfig has not worked
correctly since the introduction of CONFIG_ARCH_MULTIPLATFORM a long
time ago.

The problems is that CONFIG_BIG_ENDIAN depends on
ARCH_SUPPORTS_BIG_ENDIAN, which can set by any one platform
in the config, but would actually have to be supported by all
of them.

This was mostly ok for ARMv6/ARMv7 builds, since these are BE8 and
tend to just work aside from problems in nonportable device drivers.
For ARMv4/v5 machines, CONFIG_BIG_ENDIAN and CONFIG_ARCH_MULTIPLATFORM
were never set together, so this was disabled on all those machines
except for IXP4xx.

As IXP4xx can now become part of ARCH_MULTIPLATFORM, it seems better to
formalize this logic: all ARMv4/v5 platforms get an explicit dependency
on being either big-endian (ixp4xx) or little-endian (the rest). We may
want to fix ixp4xx in the future to support both, but it does not work
in LE mode at the moment.

For the ARMv6/v7 platforms, there are two ways this could be handled

 a) allow both modes only for platforms selecting
    'ARCH_SUPPORTS_BIG_ENDIAN' today, but only LE mode for the
    others, given that these were added intentionally at some
    point.

 b) allow both modes everwhere, given that it was already possible
    to build that way by e.g. selecting ARCH_VIRT, and that the
    list is not an accurate reflection of which platforms may or
    may not work.

Out of these, I picked b) because it seemed slighly more logical
to me.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent a3102faf

arch/arm/Kconfig

+6 −2
Original line number Diff line number Diff line
@@ -349,6 +349,7 @@ config ARCH_MULTIPLATFORM 


config ARCH_FOOTBRIDGE

	bool "FootBridge"

	depends on CPU_LITTLE_ENDIAN

	select CPU_SA110

	select FOOTBRIDGE

	select NEED_MACH_MEMORY_H
@@ -358,7 +359,7 @@ config ARCH_FOOTBRIDGE 


config ARCH_IXP4XX

	bool "IXP4xx-based"

	select ARCH_SUPPORTS_BIG_ENDIAN

	depends on CPU_BIG_ENDIAN

	select ARM_PATCH_PHYS_VIRT

	select CPU_XSCALE

	select GPIO_IXP4XX
@@ -374,6 +375,7 @@ config ARCH_IXP4XX 


config ARCH_PXA

	bool "PXA2xx/PXA3xx-based"

	depends on CPU_LITTLE_ENDIAN

	select ARCH_MTD_XIP

	select ARM_CPU_SUSPEND if PM

	select AUTO_ZRELADDR
@@ -393,6 +395,7 @@ config ARCH_PXA 
config ARCH_RPC

	bool "RiscPC"

	depends on !CC_IS_CLANG && GCC_VERSION < 90100 && GCC_VERSION >= 60000

	depends on CPU_LITTLE_ENDIAN

	select ARCH_ACORN

	select ARCH_MAY_HAVE_PC_FDC

	select ARCH_SPARSEMEM_ENABLE
@@ -411,6 +414,7 @@ config ARCH_RPC 


config ARCH_SA1100

	bool "SA1100-based"

	depends on CPU_LITTLE_ENDIAN

	select ARCH_MTD_XIP

	select ARCH_SPARSEMEM_ENABLE

	select CLKSRC_MMIO
@@ -429,6 +433,7 @@ config ARCH_SA1100 


config ARCH_OMAP1

	bool "TI OMAP1"

	depends on CPU_LITTLE_ENDIAN

	select ARCH_OMAP

	select CLKSRC_MMIO

	select GENERIC_IRQ_CHIP
@@ -505,7 +510,6 @@ config ARCH_VIRT 
	select ARM_GIC_V3_ITS if PCI

	select ARM_PSCI

	select HAVE_ARM_ARCH_TIMER

	select ARCH_SUPPORTS_BIG_ENDIAN



config ARCH_AIROHA

	bool "Airoha SoC Support"

arch/arm/mach-asm9260/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
config MACH_ASM9260

	bool "Alphascale ASM9260"

	depends on ARCH_MULTI_V5

	depends on CPU_LITTLE_ENDIAN

	select CPU_ARM926T

	select ASM9260_TIMER

	help

arch/arm/mach-aspeed/Kconfig

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

menuconfig ARCH_ASPEED

	bool "Aspeed BMC architectures"

	depends on ARCH_MULTI_V5 || ARCH_MULTI_V6 || ARCH_MULTI_V7

	depends on (CPU_LITTLE_ENDIAN && ARCH_MULTI_V5) || ARCH_MULTI_V6 || ARCH_MULTI_V7

	select SRAM

	select WATCHDOG

	select ASPEED_WATCHDOG

arch/arm/mach-at91/Kconfig

+2 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

menuconfig ARCH_AT91

	bool "AT91/Microchip SoCs"

	depends on ARCH_MULTI_V4T || ARCH_MULTI_V5 || ARCH_MULTI_V7 || ARM_SINGLE_ARMV7M

	depends on (CPU_LITTLE_ENDIAN && (ARCH_MULTI_V4T || ARCH_MULTI_V5)) || \

		ARCH_MULTI_V7 || ARM_SINGLE_ARMV7M

	select ARM_CPU_SUSPEND if PM && ARCH_MULTI_V7

	select COMMON_CLK_AT91

	select GPIOLIB

arch/arm/mach-clps711x/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
menuconfig ARCH_CLPS711X

	bool "Cirrus Logic EP721x/EP731x-based"

	depends on ARCH_MULTI_V4T

	depends on CPU_LITTLE_ENDIAN

	select CLPS711X_TIMER

	select CPU_ARM720T

	select GPIOLIB