linux-yocto/arch/arm/boot/compressed/Makefile

SPDX-License-Identifier: GPL-2.0

linux/arch/arm/boot/compressed/Makefile

create a compressed vmlinuz image from the original vmlinux

OBJS =

HEAD = head.o OBJS += misc.o decompress.o ifeq ($(CONFIG_DEBUG_UNCOMPRESS),y) OBJS += debug.o AFLAGS_head.o += -DDEBUG endif FONTC = $(srctree)/lib/fonts/font_acorn_8x8.c

string library code (-Os is enforced to keep it much smaller)

OBJS += string.o CFLAGS_string.o := -Os

ifeq ($(CONFIG_ARM_VIRT_EXT),y) OBJS += hyp-stub.o endif

GCOV_PROFILE := n KASAN_SANITIZE := n

Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.

KCOV_INSTRUMENT := n

Architecture dependencies

ifeq ($(CONFIG_ARCH_ACORN),y) OBJS += ll_char_wr.o font.o endif

ifeq ($(CONFIG_ARCH_SA1100),y) OBJS += head-sa1100.o endif

ifeq ($(CONFIG_CPU_XSCALE),y) OBJS += head-xscale.o endif

ifeq ($(CONFIG_PXA_SHARPSL_DETECT_MACH_ID),y) OBJS += head-sharpsl.o endif

ifeq ($(CONFIG_CPU_ENDIAN_BE32),y) ifeq ($(CONFIG_CPU_CP15),y) OBJS += big-endian.o else

The endian should be set by h/w design.

endif endif

We now have a PIC decompressor implementation. Decompressors running

from RAM should not define ZTEXTADDR. Decompressors running directly

from ROM or Flash must define ZTEXTADDR (preferably via the config)

FIXME: Previous assignment to ztextaddr-y is lost here. See SHARK

ifeq ($(CONFIG_ZBOOT_ROM),y) ZTEXTADDR := $(CONFIG_ZBOOT_ROM_TEXT) ZBSSADDR := $(CONFIG_ZBOOT_ROM_BSS) else ZTEXTADDR := 0 ZBSSADDR := ALIGN(8) endif

MALLOC_SIZE := 65536

AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET) -DMALLOC_SIZE=$(MALLOC_SIZE) CPPFLAGS_vmlinux.lds := -DTEXT_START="$(ZTEXTADDR)" -DBSS_START="$(ZBSSADDR)" CPPFLAGS_vmlinux.lds += -DTEXT_OFFSET="$(TEXT_OFFSET)" CPPFLAGS_vmlinux.lds += -DMALLOC_SIZE="$(MALLOC_SIZE)"

compress-$(CONFIG_KERNEL_GZIP) = gzip compress-$(CONFIG_KERNEL_LZO) = lzo_with_size compress-$(CONFIG_KERNEL_LZMA) = lzma_with_size compress-$(CONFIG_KERNEL_XZ) = xzkern_with_size compress-$(CONFIG_KERNEL_LZ4) = lz4_with_size

libfdt_objs := fdt_rw.o fdt_ro.o fdt_wip.o fdt.o

ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y) CFLAGS_REMOVE_atags_to_fdt.o += -Wframe-larger-than=${CONFIG_FRAME_WARN} CFLAGS_atags_to_fdt.o += -Wframe-larger-than=1280 OBJS += $(libfdt_objs) atags_to_fdt.o endif ifeq ($(CONFIG_USE_OF),y) OBJS += $(libfdt_objs) fdt_check_mem_start.o endif

-fstack-protector-strong triggers protection checks in this code,

but it is being used too early to link to meaningful stack_chk logic.

$(foreach o, $(libfdt_objs) atags_to_fdt.o fdt_check_mem_start.o,
$(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt -fno-stack-protector))

targets := vmlinux vmlinux.lds piggy_data piggy.o
lib1funcs.o ashldi3.o bswapsdi2.o
head.o $(OBJS)

clean-files += lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S

KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING

ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin
-I$(obj) $(DISABLE_ARM_SSP_PER_TASK_PLUGIN) ccflags-remove-$(CONFIG_FUNCTION_TRACER) += -pg asflags-y := -DZIMAGE

Supply kernel BSS size to the decompressor via a linker symbol.

KBSS_SZ = $(shell echo $$(($$($(NM) $(obj)/../../../../vmlinux |
sed -n -e 's/^[^ ]* [ABD] __bss_start$$/-0x\1/p'
-e 's/^[^ ]* [ABD] __bss_stop$$/+0x\1/p') )) ) LDFLAGS_vmlinux = --defsym _kernel_bss_size=$(KBSS_SZ)

Supply ZRELADDR to the decompressor via a linker symbol.

ifneq ($(CONFIG_AUTO_ZRELADDR),y) LDFLAGS_vmlinux += --defsym zreladdr=$(ZRELADDR) endif ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) LDFLAGS_vmlinux += --be8 endif

Report unresolved symbol references

LDFLAGS_vmlinux += --no-undefined

Delete all temporary local symbols

LDFLAGS_vmlinux += -X

Report orphan sections

ifdef CONFIG_LD_ORPHAN_WARN LDFLAGS_vmlinux += --orphan-handling=warn endif

Next argument is a linker script

LDFLAGS_vmlinux += -T

For __aeabi_uidivmod

lib1funcs = $(obj)/lib1funcs.o

$(obj)/lib1funcs.S: $(srctree)/arch/$(SRCARCH)/lib/lib1funcs.S $(call cmd,shipped)

For __aeabi_llsl

ashldi3 = $(obj)/ashldi3.o

$(obj)/ashldi3.S: $(srctree)/arch/$(SRCARCH)/lib/ashldi3.S $(call cmd,shipped)

For __bswapsi2, __bswapdi2

bswapsdi2 = $(obj)/bswapsdi2.o

$(obj)/bswapsdi2.S: $(srctree)/arch/$(SRCARCH)/lib/bswapsdi2.S $(call cmd,shipped)

We need to prevent any GOTOFF relocs being used with references

to symbols in the .bss section since we cannot relocate them

independently from the rest at run time. This can be achieved by

ensuring that no private .bss symbols exist, as global symbols

always have a GOT entry which is what we need.

The .data section is already discarded by the linker script so no need

to bother about it here.

check_for_bad_syms =
bad_syms=$$($(NM) $@ | sed -n 's/^.{8} [bc] (.*)/\1/p') &&
[ -z "$$bad_syms" ] ||
( echo "following symbols must have non local/private scope:" >&2;
echo "$$bad_syms" >&2; false )

check_for_multiple_zreladdr =
if [ $(words $(ZRELADDR)) -gt 1 -a "$(CONFIG_AUTO_ZRELADDR)" = "" ]; then
echo 'multiple zreladdrs: $(ZRELADDR)';
echo 'This needs CONFIG_AUTO_ZRELADDR to be set';
false;
fi

efi-obj-$(CONFIG_EFI_STUB) := $(objtree)/drivers/firmware/efi/libstub/lib.a

$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.o
$(addprefix $(obj)/, $(OBJS)) $(lib1funcs) $(ashldi3)
$(bswapsdi2) $(efi-obj-y) FORCE @$(check_for_multiple_zreladdr) $(call if_changed,ld) @$(check_for_bad_syms)

$(obj)/piggy_data: $(obj)/../Image FORCE $(call if_changed,$(compress-y))

$(obj)/piggy.o: $(obj)/piggy_data

CFLAGS_font.o := -Dstatic=

$(obj)/font.c: $(FONTC) $(call cmd,shipped)

AFLAGS_hyp-stub.o := -Wa,-march=armv7-a

$(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S $(call cmd,shipped)