linux/arch/riscv/Makefile
Vitaly Wool 44c9225729
RISC-V: enable XIP
Introduce XIP (eXecute In Place) support for RISC-V platforms.
It allows code to be executed directly from non-volatile storage
directly addressable by the CPU, such as QSPI NOR flash which can
be found on many RISC-V platforms. This makes way for significant
optimization of RAM footprint. The XIP kernel is not compressed
since it has to run directly from flash, so it will occupy more
space on the non-volatile storage. The physical flash address used
to link the kernel object files and for storing it has to be known
at compile time and is represented by a Kconfig option.

XIP on RISC-V will for the time being only work on MMU-enabled
kernels.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
[Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ]
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: disable XIP for allyesconfig]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:31:28 -07:00

126 lines
3.5 KiB
Makefile

# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies. Remember to do have actions
# for "archclean" and "archdep" for cleaning up and making dependencies for
# this architecture
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
OBJCOPYFLAGS := -O binary
LDFLAGS_vmlinux :=
ifeq ($(CONFIG_DYNAMIC_FTRACE),y)
LDFLAGS_vmlinux := --no-relax
KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
CC_FLAGS_FTRACE := -fpatchable-function-entry=8
endif
ifeq ($(CONFIG_64BIT)$(CONFIG_CMODEL_MEDLOW),yy)
KBUILD_CFLAGS_MODULE += -mcmodel=medany
endif
export BITS
ifeq ($(CONFIG_ARCH_RV64I),y)
BITS := 64
UTS_MACHINE := riscv64
KBUILD_CFLAGS += -mabi=lp64
KBUILD_AFLAGS += -mabi=lp64
KBUILD_LDFLAGS += -melf64lriscv
else
BITS := 32
UTS_MACHINE := riscv32
KBUILD_CFLAGS += -mabi=ilp32
KBUILD_AFLAGS += -mabi=ilp32
KBUILD_LDFLAGS += -melf32lriscv
endif
# ISA string setting
riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima
riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima
riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd
riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c
KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
KBUILD_AFLAGS += -march=$(riscv-march-y)
KBUILD_CFLAGS += -mno-save-restore
KBUILD_CFLAGS += -DCONFIG_PAGE_OFFSET=$(CONFIG_PAGE_OFFSET)
ifeq ($(CONFIG_CMODEL_MEDLOW),y)
KBUILD_CFLAGS += -mcmodel=medlow
endif
ifeq ($(CONFIG_CMODEL_MEDANY),y)
KBUILD_CFLAGS += -mcmodel=medany
endif
ifeq ($(CONFIG_PERF_EVENTS),y)
KBUILD_CFLAGS += -fno-omit-frame-pointer
endif
KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-relax)
# GCC versions that support the "-mstrict-align" option default to allowing
# unaligned accesses. While unaligned accesses are explicitly allowed in the
# RISC-V ISA, they're emulated by machine mode traps on all extant
# architectures. It's faster to have GCC emit only aligned accesses.
KBUILD_CFLAGS += $(call cc-option,-mstrict-align)
ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
prepare: stack_protector_prepare
stack_protector_prepare: prepare0
$(eval KBUILD_CFLAGS += -mstack-protector-guard=tls \
-mstack-protector-guard-reg=tp \
-mstack-protector-guard-offset=$(shell \
awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}' \
include/generated/asm-offsets.h))
endif
# arch specific predefines for sparse
CHECKFLAGS += -D__riscv -D__riscv_xlen=$(BITS)
# Default target when executing plain make
boot := arch/riscv/boot
ifeq ($(CONFIG_XIP_KERNEL),y)
KBUILD_IMAGE := $(boot)/xipImage
else
KBUILD_IMAGE := $(boot)/Image.gz
endif
head-y := arch/riscv/kernel/head.o
core-y += arch/riscv/
core-$(CONFIG_RISCV_ERRATA_ALTERNATIVE) += arch/riscv/errata/
libs-y += arch/riscv/lib/
libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
PHONY += vdso_install
vdso_install:
$(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@
ifneq ($(CONFIG_XIP_KERNEL),y)
ifeq ($(CONFIG_RISCV_M_MODE)$(CONFIG_SOC_CANAAN),yy)
KBUILD_IMAGE := $(boot)/loader.bin
else
KBUILD_IMAGE := $(boot)/Image.gz
endif
endif
BOOT_TARGETS := Image Image.gz loader loader.bin xipImage
all: $(notdir $(KBUILD_IMAGE))
$(BOOT_TARGETS): vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
@$(kecho) ' Kernel: $(boot)/$@ is ready'
Image.%: Image
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
zinstall install:
$(Q)$(MAKE) $(build)=$(boot) $@
archclean:
$(Q)$(MAKE) $(clean)=$(boot)