u-boot/arch/arm/cpu/armv8/config.mk

# SPDX-License-Identifier: GPL-2.0+
#
# (C) Copyright 2002
# Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
PLATFORM_RELFLAGS += -fno-common -ffixed-x18
PLATFORM_RELFLAGS += $(call cc-option,-mbranch-protection=none)

PF_NO_UNALIGNED := $(call cc-option, -mstrict-align)
PLATFORM_CPPFLAGS += $(PF_NO_UNALIGNED)

EFI_LDS := elf_aarch64_efi.lds
EFI_CRT0 := crt0_aarch64_efi.o
EFI_RELOC := reloc_aarch64_efi.o
SPDX: Convert all of our single license tags to Linux Kernel style When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com> 2018-05-06 21:58:06 +00:00			`# SPDX-License-Identifier: GPL-2.0+`
arm64: core support Relocation code based on a patch by Scott Wood, which is: Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: David Feng <fenghua@phytium.com.cn> 2013-12-14 03:47:35 +00:00			`#`
			`# (C) Copyright 2002`
			`# Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>`
			`PLATFORM_RELFLAGS += -fno-common -ffixed-x18`
arm64: explicitly disable pointer authentication instructions The Yocto project builds their aarch64 cross-compiler with the configure knob --enable-standard-branch-protection, which means that their gcc behaves as if -mbranch-protection=standard is passed; the default (lacking that configure knob) is -mbranch-protection=none. This means that when building U-Boot using the Yocto toolchain, most functions end up containing paciasp/autiasp/bti instructions. However, since U-Boot is not an ordinary userspace application, there's no OS kernel which has set up the required authentication keys, so these instructions do nothing at all (even on arm64 hardware that does have the pointer authentication capability). They do however make the image larger. It is theoretically possible for U-Boot to make use of the pointer authentication protection - cf. the linux kernel's CONFIG_ARM64_PTR_AUTH_KERNEL - but it is far from trivial, and it's hard to see just what threat model it would protect against in a bootloader context. Regardless, we certainly have none of the required infrastructure now, so explicitly pass -mbranch-protection=none to ensure those useless instructions do not get emitted. For a toolchain not configured with --enable-standard-branch-protection, this changes nothing. For the Yocto toolchain, this reduces the size of both SPL and U-Boot proper by about 3% for my imx8mp target. If you don't have a Yocto toolchain, the effect can easily be reproduced by applying this patch and changing =none to =standard. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Reviewed-by: Simon Glass <sjg@chromium.org> 2022-08-08 14:12:30 +00:00			`PLATFORM_RELFLAGS += $(call cc-option,-mbranch-protection=none)`
arm64: core support Relocation code based on a patch by Scott Wood, which is: Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: David Feng <fenghua@phytium.com.cn> 2013-12-14 03:47:35 +00:00
arm: Switch to -mno-unaligned-access when supported by the compiler When we tell the compiler to optimize for ARMv7 (and ARMv6 for that matter) it assumes a default of SCTRL.A being cleared and unaligned accesses being allowed and fast at the hardware level. We set this bit and must pass along -mno-unaligned-access so that the compiler will still breakdown accesses and not trigger a data abort. To better help understand the requirements of the project with respect to unaligned memory access, the Documentation/unaligned-memory-access.txt file has been added as doc/README.unaligned-memory-access.txt and is taken from the v3.14-rc1 tag of the kernel. Cc: Albert ARIBAUD <albert.u.boot@aribaud.net> Cc: Mans Rullgard <mans@mansr.com> Signed-off-by: Tom Rini <trini@ti.com> 2014-02-25 15:27:01 +00:00			`PF_NO_UNALIGNED := $(call cc-option, -mstrict-align)`
arm64: core support Relocation code based on a patch by Scott Wood, which is: Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: David Feng <fenghua@phytium.com.cn> 2013-12-14 03:47:35 +00:00			`PLATFORM_CPPFLAGS += $(PF_NO_UNALIGNED)`
efi: arm: Add aarch64 EFI app support Add support for EFI apps on aarch64. This includes start-up and relocation code plus a link script. Signed-off-by: Simon Glass <sjg@chromium.org> [agraf: add kconfig dep] Signed-off-by: Alexander Graf <agraf@suse.de> 2016-11-07 15:47:11 +00:00
			`EFI_LDS := elf_aarch64_efi.lds`
			`EFI_CRT0 := crt0_aarch64_efi.o`
			`EFI_RELOC := reloc_aarch64_efi.o`