This may be a strong opinion but I would consider toolchains that explicitly change the default -march from the well understood x86-64 (which all 64-bit processors support) to be totally broken. If a distro wants to switch the -march for the packages, override CFLAGS :)

On Wed, Jun 29, 2022 at 10:57 PM dann frazier <dann.frazier@canonical.com> wrote:
Ping on this. Would it be more palatable if I limited the change only
to tested toolchains (gcc/clang)? Alternatively, is there a way to
submit this code to CI to verify the !(gcc|clang) variants?

  -dann

On Fri, Jun 10, 2022 at 12:09:18PM -0600, dann frazier wrote:
> From: dann frazier <dann.frazier@canonical.com>
>
> Some Linux distributions are experimenting with builds that target a
> higher x86-64 psABI, such as x86-64-v3. To avoid inheriting these
> compiler defaults in edk2 builds, and therefore breaking compatibility
> with machines using older CPUs, explicitly target the generic x86-64
> psABI. This is similar to how we explicitly specify the cpu type for
> some other architectures (-march=i586 for IA32, -march=armv7-a for ARM).
>
> Spot tested with OVMF builds using GCC5 and CLANG38.
>
> Signed-off-by: dann frazier <dann.frazier@canonical.com>
> ---
>  BaseTools/Conf/tools_def.template | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
> index adcd23f727..569d16fb3e 100755
> --- a/BaseTools/Conf/tools_def.template
> +++ b/BaseTools/Conf/tools_def.template
> @@ -1885,7 +1885,7 @@ DEFINE GCC_DEPS_FLAGS              = -MMD -MF $@.deps
>  DEFINE GCC48_ALL_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -ffunction-sections -fdata-sections -DSTRING_ARRAY_NAME=$(BASE_NAME)Strings
>  DEFINE GCC48_IA32_X64_DLINK_COMMON   = -nostdlib -Wl,-n,-q,--gc-sections -z common-page-size=0x20
>  DEFINE GCC48_IA32_CC_FLAGS           = DEF(GCC48_ALL_CC_FLAGS) -m32 -march=i586 -malign-double -fno-stack-protector -D EFI32 -fno-asynchronous-unwind-tables -Wno-address
> -DEFINE GCC48_X64_CC_FLAGS            = DEF(GCC48_ALL_CC_FLAGS) -m64 -fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" -maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=small -fpie -fno-asynchronous-unwind-tables -Wno-address
> +DEFINE GCC48_X64_CC_FLAGS            = DEF(GCC48_ALL_CC_FLAGS) -m64 -march=x86-64 -fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" -maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=small -fpie -fno-asynchronous-unwind-tables -Wno-address
>  DEFINE GCC48_IA32_X64_ASLDLINK_FLAGS = DEF(GCC48_IA32_X64_DLINK_COMMON) -Wl,--entry,ReferenceAcpiTable -u ReferenceAcpiTable
>  DEFINE GCC48_IA32_X64_DLINK_FLAGS    = DEF(GCC48_IA32_X64_DLINK_COMMON) -Wl,--entry,$(IMAGE_ENTRY_POINT) -u $(IMAGE_ENTRY_POINT) -Wl,-Map,$(DEST_DIR_DEBUG)/$(BASE_NAME).map,--whole-archive
>  DEFINE GCC48_IA32_DLINK2_FLAGS       = -Wl,--defsym=PECOFF_HEADER_SIZE=0x220 DEF(GCC_DLINK2_FLAGS_COMMON)
> @@ -2613,15 +2613,15 @@ NOOPT_CLANG38_IA32_DLINK2_FLAGS     = DEF(GCC5_IA32_DLINK2_FLAGS) -O0
>  *_CLANG38_X64_ASLPP_FLAGS          = DEF(GCC_ASLPP_FLAGS) DEF(CLANG38_X64_TARGET)
>  *_CLANG38_X64_VFRPP_FLAGS          = DEF(GCC_VFRPP_FLAGS) DEF(CLANG38_X64_TARGET)

> -DEBUG_CLANG38_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET) -g
> +DEBUG_CLANG38_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET) -g
>  DEBUG_CLANG38_X64_DLINK_FLAGS      = DEF(GCC5_IA32_X64_DLINK_FLAGS) -flto -Wl,-Oz -Wl,-melf_x86_64 -Wl,--oformat=elf64-x86-64 -Wl,-pie -mcmodel=small
>  DEBUG_CLANG38_X64_DLINK2_FLAGS     = DEF(GCC5_X64_DLINK2_FLAGS) -O3

> -RELEASE_CLANG38_X64_CC_FLAGS       = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET)
> +RELEASE_CLANG38_X64_CC_FLAGS       = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET)
>  RELEASE_CLANG38_X64_DLINK_FLAGS    = DEF(GCC5_IA32_X64_DLINK_FLAGS) -flto -Wl,-Oz -Wl,-melf_x86_64 -Wl,--oformat=elf64-x86-64 -Wl,-pie -mcmodel=small
>  RELEASE_CLANG38_X64_DLINK2_FLAGS   = DEF(GCC5_X64_DLINK2_FLAGS) -O3

> -NOOPT_CLANG38_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANG38_X64_TARGET) -g
> +NOOPT_CLANG38_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANG38_X64_TARGET) -g
>  NOOPT_CLANG38_X64_DLINK_FLAGS      = DEF(GCC5_IA32_X64_DLINK_FLAGS) -Wl,-O0 -Wl,-melf_x86_64 -Wl,--oformat=elf64-x86-64 -Wl,-pie -mcmodel=small
>  NOOPT_CLANG38_X64_DLINK2_FLAGS     = DEF(GCC5_X64_DLINK2_FLAGS) -O0

> @@ -2798,17 +2798,17 @@ NOOPT_CLANGPDB_IA32_DLINK2_FLAGS     =
>  *_CLANGPDB_X64_ASLPP_FLAGS          = DEF(GCC_ASLPP_FLAGS) DEF(CLANGPDB_X64_TARGET)
>  *_CLANGPDB_X64_VFRPP_FLAGS          = DEF(GCC_VFRPP_FLAGS) DEF(CLANGPDB_X64_TARGET)

> -DEBUG_CLANGPDB_X64_CC_FLAGS         = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -Oz -flto DEF(CLANGPDB_X64_TARGET) -gcodeview  -funwind-tables
> +DEBUG_CLANGPDB_X64_CC_FLAGS         = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -Oz -flto DEF(CLANGPDB_X64_TARGET) -gcodeview  -funwind-tables
>  DEBUG_CLANGPDB_X64_DLINK_FLAGS      = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /ALIGN:32 /FILEALIGN:32 /Machine:X64 /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DEBUG:GHASH /MLLVM:-exception-model=wineh /lldmap
>  DEBUG_CLANGPDB_X64_DLINK2_FLAGS     =
>  DEBUG_CLANGPDB_X64_GENFW_FLAGS      = --keepexceptiontable

> -RELEASE_CLANGPDB_X64_CC_FLAGS       = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -Oz -flto DEF(CLANGPDB_X64_TARGET) -fno-unwind-tables
> +RELEASE_CLANGPDB_X64_CC_FLAGS       = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -Oz -flto DEF(CLANGPDB_X64_TARGET) -fno-unwind-tables
>  RELEASE_CLANGPDB_X64_DLINK_FLAGS    = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /IGNORE:4254 /OPT:REF /OPT:ICF=10 /ALIGN:32 /FILEALIGN:32 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /MERGE:.rdata=.data /MLLVM:-exception-model=wineh /lldmap
>  RELEASE_CLANGPDB_X64_DLINK2_FLAGS   =
>  RELEASE_CLANGPDB_X64_GENFW_FLAGS    =

> -NOOPT_CLANGPDB_X64_CC_FLAGS         = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -O0 DEF(CLANGPDB_X64_TARGET) -gcodeview -funwind-tables
> +NOOPT_CLANGPDB_X64_CC_FLAGS         = DEF(CLANGPDB_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -O0 DEF(CLANGPDB_X64_TARGET) -gcodeview -funwind-tables
>  NOOPT_CLANGPDB_X64_DLINK_FLAGS      = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /ALIGN:32 /FILEALIGN:32 /Machine:X64 /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DEBUG:GHASH /MLLVM:-exception-model=wineh /lldmap
>  NOOPT_CLANGPDB_X64_DLINK2_FLAGS     =
>  NOOPT_CLANGPDB_X64_GENFW_FLAGS      = --keepexceptiontable
> @@ -2901,15 +2901,15 @@ NOOPT_CLANGDWARF_IA32_DLINK2_FLAGS     = DEF(CLANGDWARF_IA32_DLINK2_FLAGS) -O0 -
>  *_CLANGDWARF_X64_ASLPP_FLAGS          = DEF(GCC_ASLPP_FLAGS) DEF(CLANG38_X64_TARGET)
>  *_CLANGDWARF_X64_VFRPP_FLAGS          = DEF(GCC_VFRPP_FLAGS) DEF(CLANG38_X64_TARGET)

> -DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET) -g
> +DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET) -g
>  DEBUG_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  DEBUG_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld

> -RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET)
> +RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANG38_X64_TARGET)
>  RELEASE_CLANGDWARF_X64_DLINK_FLAGS    = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  RELEASE_CLANGDWARF_X64_DLINK2_FLAGS   = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld

> -NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANG38_X64_TARGET) -g
> +NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANG38_ALL_CC_FLAGS) -m64 -march=x86-64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANG38_X64_TARGET) -g
>  NOOPT_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -Wl,-O0 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  NOOPT_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O0 -fuse-ld=lld








--
Pedro Falcato