libpayload: Set reasonable arch defaults

This makes it easy to switch between x86_32 and x86_64 in payloads.

Change-Id: I3ac5f24d83dc80db924e92b53403c477e6256c44
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84014
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

payloads/coreinfo/Makefile

@@ -19,8 +19,6 @@ OBJECTS = cpuinfo_module.o cpuid.S.o pci_module.o coreboot_module.o \
 OBJS    = $(patsubst %,$(obj)/%,$(OBJECTS))
 TARGET  = $(obj)/coreinfo.elf
 
-ARCH := x86_32
-
 all: real-all
 
 include ../libpayload/Makefile.payload

payloads/libpayload/Makefile.payload

@@ -32,14 +32,8 @@ DEFAULT_DEPS += $(PAYLOAD_DEPS)
 
 obj ?= build
 
-ARCH ?=
 OBJS ?=
 CCACHE ?=
-
-CFLAGS  = $(CFLAGS_$(ARCH))
-CFLAGS += -Os -ffreestanding
-CFLAGS += -Wall -Wextra -Wmissing-prototypes -Wvla -Werror
-
 STRIP ?= debug
 
 $(TARGET):
@@ -78,6 +72,20 @@ $(error $(xcompile) deleted because it's invalid. \
         Restarting the build should fix that, or explain the problem.)
 endif
 
+ifeq ($(CONFIG_LP_ARCH_ARM),y)
+ARCH ?= arm
+else ifeq ($(CONFIG_LP_ARCH_X86_64),y)
+ARCH ?= x86_64
+else ifeq ($(CONFIG_LP_ARCH_X86_32),y)
+ARCH ?= x86_32
+else ifeq ($(CONFIG_LP_ARCH_ARM64),y)
+ARCH ?= arm64
+endif
+
+CFLAGS  = $(CFLAGS_$(ARCH))
+CFLAGS += -Os -ffreestanding
+CFLAGS += -Wall -Wextra -Wmissing-prototypes -Wvla -Werror
+
 # `lpgcc` in in-tree mode:
 LPGCC  = CC="$(CCACHE) $(CC_$(ARCH))"
 LPGCC += _OBJ="$(LIBPAYLOAD_OBJ)"

payloads/nvramcui/Makefile

@@ -1,6 +1,5 @@
 unexport $(COREBOOT_EXPORTS)
 
-ARCH = x86_32
 OBJS = $(obj)/nvramcui.o
 TARGET = $(obj)/nvramcui.elf