[RFC v6 01/21] um: split build in kernel and host parts
Anton Ivanov
anton.ivanov at cambridgegreys.com
Thu Sep 24 03:33:49 EDT 2020
On 24/09/2020 08:12, Hajime Tazaki wrote:
> From: Octavian Purdila <tavi at cs.pub.ro>
>
> This patch splits the UML build in two parts: a kernel part that
> generates a relocatable object (linux.o) and a host build part that
> links the relocatable object into an executable.
>
> This allows us to simplify the linker script since we can now remove
> the host bits (e.g. .rel sections). It also gives us greater
> flexibility since it will be much easier to support other
> architectures and OSes if we use the standard linker script.
>
> The host build part has been implemented in tools/um so that we can
> reuse the available host build infrastructure.
>
> The patch also changes the UML build invocation, if before
>
> $ make ARCH=um defconfig
> $ make ARCH=um
>
> was generating the executable now this only generates the relocatable
> object.
This will break packaging in all distributions. We need to figure out an alternative way which is backward compatible with their builds.
>
> To fully build UML use:
>
> $ make -C tools/um
>
> which will generate tools/lkl/linux as the UML executable. To
> statically compiled UML use:
>
> $ make -C tools/lkl UML_STATIC=y
>
> Signed-off-by: Octavian Purdila <tavi at cs.pub.ro>
> Signed-off-by: Hajime Tazaki <thehajime at gmail.com>
> ---
> arch/um/Kconfig | 12 +--
> arch/um/Makefile | 14 ++-
> arch/um/include/asm/common.lds.S | 99 ------------------
> arch/um/kernel/dyn.lds.S | 171 -------------------------------
> arch/um/kernel/uml.lds.S | 115 ---------------------
> arch/um/kernel/vmlinux.lds.S | 91 ++++++++++++++--
> scripts/link-vmlinux.sh | 42 +++-----
> tools/um/Makefile | 72 +++++++++++++
> tools/um/Targets | 4 +
> tools/um/uml/Build | 0
> 10 files changed, 184 insertions(+), 436 deletions(-)
> delete mode 100644 arch/um/include/asm/common.lds.S
> delete mode 100644 arch/um/kernel/dyn.lds.S
> delete mode 100644 arch/um/kernel/uml.lds.S
> create mode 100644 tools/um/Makefile
> create mode 100644 tools/um/Targets
> create mode 100644 tools/um/uml/Build
>
> diff --git a/arch/um/Kconfig b/arch/um/Kconfig
> index eb51fec75948..e41d31d0d875 100644
> --- a/arch/um/Kconfig
> +++ b/arch/um/Kconfig
> @@ -20,6 +20,7 @@ config UML
> select GENERIC_CLOCKEVENTS
> select HAVE_GCC_PLUGINS
> select TTY # Needed for line.c
> + select MODULE_REL_CRCS if MODVERSIONS
>
> config MMU
> bool
> @@ -79,17 +80,6 @@ config STATIC_LINK
> NOTE: This option is incompatible with some networking features which
> depend on features that require being dynamically loaded (like NSS).
>
> -config LD_SCRIPT_STATIC
> - bool
> - default y
> - depends on STATIC_LINK
> -
> -config LD_SCRIPT_DYN
> - bool
> - default y
> - depends on !LD_SCRIPT_STATIC
> - select MODULE_REL_CRCS if MODVERSIONS
> -
> config HOSTFS
> tristate "Host filesystem"
> help
> diff --git a/arch/um/Makefile b/arch/um/Makefile
> index 1cea46ff9bb7..fdfaff4633e8 100644
> --- a/arch/um/Makefile
> +++ b/arch/um/Makefile
> @@ -95,14 +95,20 @@ KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
> KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
> -Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
> KBUILD_CFLAGS += $(KERNEL_DEFINES)
> +LDFLAGS_vmlinux += -r
>
> -PHONY += linux
> +PHONY += linux.o
>
> -all: linux
> +all: linux.o
>
> -linux: vmlinux
> +linux.o: vmlinux
> @echo ' LINK $@'
> - $(Q)ln -f $< $@
> + $(Q)$(OBJCOPY) -R .eh_frame $< $@
> +
> +install: linux.o
> + @echo " INSTALL $(INSTALL_PATH)/lib/$<"
> + @mkdir -p $(INSTALL_PATH)/lib/
> + @cp $< $(INSTALL_PATH)/lib/
>
> define archhelp
> echo '* linux - Binary kernel image (./linux) - for backward'
> diff --git a/arch/um/include/asm/common.lds.S b/arch/um/include/asm/common.lds.S
> deleted file mode 100644
> index eca6c452a41b..000000000000
> --- a/arch/um/include/asm/common.lds.S
> +++ /dev/null
> @@ -1,99 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#include <asm-generic/vmlinux.lds.h>
> -
> - .fini : { *(.fini) } =0x9090
> - _etext = .;
> - PROVIDE (etext = .);
> -
> - . = ALIGN(4096);
> - _sdata = .;
> - PROVIDE (sdata = .);
> -
> - RO_DATA(4096)
> -
> - .unprotected : { *(.unprotected) }
> - . = ALIGN(4096);
> - PROVIDE (_unprotected_end = .);
> -
> - . = ALIGN(4096);
> - EXCEPTION_TABLE(0)
> -
> - BUG_TABLE
> -
> - .uml.setup.init : {
> - __uml_setup_start = .;
> - *(.uml.setup.init)
> - __uml_setup_end = .;
> - }
> -
> - .uml.help.init : {
> - __uml_help_start = .;
> - *(.uml.help.init)
> - __uml_help_end = .;
> - }
> -
> - .uml.postsetup.init : {
> - __uml_postsetup_start = .;
> - *(.uml.postsetup.init)
> - __uml_postsetup_end = .;
> - }
> -
> - .init.setup : {
> - INIT_SETUP(0)
> - }
> -
> - PERCPU_SECTION(32)
> -
> - .initcall.init : {
> - INIT_CALLS
> - }
> -
> - .con_initcall.init : {
> - CON_INITCALL
> - }
> -
> - .exitcall : {
> - __exitcall_begin = .;
> - *(.exitcall.exit)
> - __exitcall_end = .;
> - }
> -
> - .uml.exitcall : {
> - __uml_exitcall_begin = .;
> - *(.uml.exitcall.exit)
> - __uml_exitcall_end = .;
> - }
> -
> - . = ALIGN(4);
> - .altinstructions : {
> - __alt_instructions = .;
> - *(.altinstructions)
> - __alt_instructions_end = .;
> - }
> - .altinstr_replacement : { *(.altinstr_replacement) }
> - /* .exit.text is discard at runtime, not link time, to deal with references
> - from .altinstructions and .eh_frame */
> - .exit.text : { EXIT_TEXT }
> - .exit.data : { *(.exit.data) }
> -
> - .preinit_array : {
> - __preinit_array_start = .;
> - *(.preinit_array)
> - __preinit_array_end = .;
> - }
> - .init_array : {
> - __init_array_start = .;
> - *(.init_array)
> - __init_array_end = .;
> - }
> - .fini_array : {
> - __fini_array_start = .;
> - *(.fini_array)
> - __fini_array_end = .;
> - }
> -
> - . = ALIGN(4096);
> - .init.ramfs : {
> - INIT_RAM_FS
> - }
> -
> diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
> deleted file mode 100644
> index f5001481010c..000000000000
> --- a/arch/um/kernel/dyn.lds.S
> +++ /dev/null
> @@ -1,171 +0,0 @@
> -#include <asm/vmlinux.lds.h>
> -#include <asm/page.h>
> -
> -OUTPUT_FORMAT(ELF_FORMAT)
> -OUTPUT_ARCH(ELF_ARCH)
> -ENTRY(_start)
> -jiffies = jiffies_64;
> -
> -SECTIONS
> -{
> - PROVIDE (__executable_start = START);
> - . = START + SIZEOF_HEADERS;
> - .interp : { *(.interp) }
> - __binary_start = .;
> - . = ALIGN(4096); /* Init code and data */
> - _text = .;
> - INIT_TEXT_SECTION(PAGE_SIZE)
> -
> - . = ALIGN(PAGE_SIZE);
> -
> - /* Read-only sections, merged into text segment: */
> - .hash : { *(.hash) }
> - .gnu.hash : { *(.gnu.hash) }
> - .dynsym : { *(.dynsym) }
> - .dynstr : { *(.dynstr) }
> - .gnu.version : { *(.gnu.version) }
> - .gnu.version_d : { *(.gnu.version_d) }
> - .gnu.version_r : { *(.gnu.version_r) }
> - .rel.init : { *(.rel.init) }
> - .rela.init : { *(.rela.init) }
> - .rel.text : { *(.rel.text .rel.text.* .rel.gnu.linkonce.t.*) }
> - .rela.text : { *(.rela.text .rela.text.* .rela.gnu.linkonce.t.*) }
> - .rel.fini : { *(.rel.fini) }
> - .rela.fini : { *(.rela.fini) }
> - .rel.rodata : { *(.rel.rodata .rel.rodata.* .rel.gnu.linkonce.r.*) }
> - .rela.rodata : { *(.rela.rodata .rela.rodata.* .rela.gnu.linkonce.r.*) }
> - .rel.data : { *(.rel.data .rel.data.* .rel.gnu.linkonce.d.*) }
> - .rela.data : { *(.rela.data .rela.data.* .rela.gnu.linkonce.d.*) }
> - .rel.tdata : { *(.rel.tdata .rel.tdata.* .rel.gnu.linkonce.td.*) }
> - .rela.tdata : { *(.rela.tdata .rela.tdata.* .rela.gnu.linkonce.td.*) }
> - .rel.tbss : { *(.rel.tbss .rel.tbss.* .rel.gnu.linkonce.tb.*) }
> - .rela.tbss : { *(.rela.tbss .rela.tbss.* .rela.gnu.linkonce.tb.*) }
> - .rel.ctors : { *(.rel.ctors) }
> - .rela.ctors : { *(.rela.ctors) }
> - .rel.dtors : { *(.rel.dtors) }
> - .rela.dtors : { *(.rela.dtors) }
> - .rel.got : { *(.rel.got) }
> - .rela.got : { *(.rela.got) }
> - .rel.bss : { *(.rel.bss .rel.bss.* .rel.gnu.linkonce.b.*) }
> - .rela.bss : { *(.rela.bss .rela.bss.* .rela.gnu.linkonce.b.*) }
> - .rel.plt : {
> - *(.rel.plt)
> - PROVIDE_HIDDEN(__rel_iplt_start = .);
> - *(.rel.iplt)
> - PROVIDE_HIDDEN(__rel_iplt_end = .);
> - }
> - .rela.plt : {
> - *(.rela.plt)
> - PROVIDE_HIDDEN(__rela_iplt_start = .);
> - *(.rela.iplt)
> - PROVIDE_HIDDEN(__rela_iplt_end = .);
> - }
> - .init : {
> - KEEP (*(.init))
> - } =0x90909090
> - .plt : { *(.plt) }
> - .text : {
> - _stext = .;
> - TEXT_TEXT
> - SCHED_TEXT
> - CPUIDLE_TEXT
> - LOCK_TEXT
> - IRQENTRY_TEXT
> - SOFTIRQENTRY_TEXT
> - *(.fixup)
> - *(.stub .text.* .gnu.linkonce.t.*)
> - /* .gnu.warning sections are handled specially by elf32.em. */
> - *(.gnu.warning)
> -
> - . = ALIGN(PAGE_SIZE);
> - } =0x90909090
> - . = ALIGN(PAGE_SIZE);
> - .syscall_stub : {
> - __syscall_stub_start = .;
> - *(.__syscall_stub*)
> - __syscall_stub_end = .;
> - }
> - .fini : {
> - KEEP (*(.fini))
> - } =0x90909090
> -
> - .kstrtab : { *(.kstrtab) }
> -
> - #include <asm/common.lds.S>
> -
> - __init_begin = .;
> - init.data : { INIT_DATA }
> - __init_end = .;
> -
> - /* Ensure the __preinit_array_start label is properly aligned. We
> - could instead move the label definition inside the section, but
> - the linker would then create the section even if it turns out to
> - be empty, which isn't pretty. */
> - . = ALIGN(32 / 8);
> - .preinit_array : { *(.preinit_array) }
> - .init_array : { *(.init_array) }
> - .fini_array : { *(.fini_array) }
> - .data : {
> - INIT_TASK_DATA(KERNEL_STACK_SIZE)
> - . = ALIGN(KERNEL_STACK_SIZE);
> - *(.data..init_irqstack)
> - DATA_DATA
> - *(.data.* .gnu.linkonce.d.*)
> - SORT(CONSTRUCTORS)
> - }
> - .data1 : { *(.data1) }
> - .tdata : { *(.tdata .tdata.* .gnu.linkonce.td.*) }
> - .tbss : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
> - .eh_frame : { KEEP (*(.eh_frame)) }
> - .gcc_except_table : { *(.gcc_except_table) }
> - .dynamic : { *(.dynamic) }
> - .ctors : {
> - /* gcc uses crtbegin.o to find the start of
> - the constructors, so we make sure it is
> - first. Because this is a wildcard, it
> - doesn't matter if the user does not
> - actually link against crtbegin.o; the
> - linker won't look for a file to match a
> - wildcard. The wildcard also means that it
> - doesn't matter which directory crtbegin.o
> - is in. */
> - KEEP (*crtbegin.o(.ctors))
> - /* We don't want to include the .ctor section from
> - from the crtend.o file until after the sorted ctors.
> - The .ctor section from the crtend file contains the
> - end of ctors marker and it must be last */
> - KEEP (*(EXCLUDE_FILE (*crtend.o ) .ctors))
> - KEEP (*(SORT(.ctors.*)))
> - KEEP (*(.ctors))
> - }
> - .dtors : {
> - KEEP (*crtbegin.o(.dtors))
> - KEEP (*(EXCLUDE_FILE (*crtend.o ) .dtors))
> - KEEP (*(SORT(.dtors.*)))
> - KEEP (*(.dtors))
> - }
> - .jcr : { KEEP (*(.jcr)) }
> - .got : { *(.got.plt) *(.got) }
> - _edata = .;
> - PROVIDE (edata = .);
> - .bss : {
> - __bss_start = .;
> - *(.dynbss)
> - *(.bss .bss.* .gnu.linkonce.b.*)
> - *(COMMON)
> - /* Align here to ensure that the .bss section occupies space up to
> - _end. Align after .bss to ensure correct alignment even if the
> - .bss section disappears because there are no input sections. */
> - . = ALIGN(32 / 8);
> - . = ALIGN(32 / 8);
> - }
> - __bss_stop = .;
> - _end = .;
> - PROVIDE (end = .);
> -
> - STABS_DEBUG
> -
> - DWARF_DEBUG
> -
> - DISCARDS
> -}
> diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
> deleted file mode 100644
> index 3b6dab3d4501..000000000000
> --- a/arch/um/kernel/uml.lds.S
> +++ /dev/null
> @@ -1,115 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#include <asm/vmlinux.lds.h>
> -#include <asm/page.h>
> -
> -OUTPUT_FORMAT(ELF_FORMAT)
> -OUTPUT_ARCH(ELF_ARCH)
> -ENTRY(_start)
> -jiffies = jiffies_64;
> -
> -SECTIONS
> -{
> - /* This must contain the right address - not quite the default ELF one.*/
> - PROVIDE (__executable_start = START);
> - /* Static binaries stick stuff here, like the sigreturn trampoline,
> - * invisibly to objdump. So, just make __binary_start equal to the very
> - * beginning of the executable, and if there are unmapped pages after this,
> - * they are forever unusable.
> - */
> - __binary_start = START;
> -
> - . = START + SIZEOF_HEADERS;
> - . = ALIGN(PAGE_SIZE);
> -
> - _text = .;
> - INIT_TEXT_SECTION(0)
> -
> - .text :
> - {
> - _stext = .;
> - TEXT_TEXT
> - SCHED_TEXT
> - CPUIDLE_TEXT
> - LOCK_TEXT
> - IRQENTRY_TEXT
> - SOFTIRQENTRY_TEXT
> - *(.fixup)
> - /* .gnu.warning sections are handled specially by elf32.em. */
> - *(.gnu.warning)
> - *(.gnu.linkonce.t*)
> - }
> -
> - . = ALIGN(PAGE_SIZE);
> - .syscall_stub : {
> - __syscall_stub_start = .;
> - *(.__syscall_stub*)
> - __syscall_stub_end = .;
> - }
> -
> - /*
> - * These are needed even in a static link, even if they wind up being empty.
> - * Newer glibc needs these __rel{,a}_iplt_{start,end} symbols.
> - */
> - .rel.plt : {
> - *(.rel.plt)
> - PROVIDE_HIDDEN(__rel_iplt_start = .);
> - *(.rel.iplt)
> - PROVIDE_HIDDEN(__rel_iplt_end = .);
> - }
> - .rela.plt : {
> - *(.rela.plt)
> - PROVIDE_HIDDEN(__rela_iplt_start = .);
> - *(.rela.iplt)
> - PROVIDE_HIDDEN(__rela_iplt_end = .);
> - }
> -
> - #include <asm/common.lds.S>
> -
> - __init_begin = .;
> - init.data : { INIT_DATA }
> - __init_end = .;
> -
> - .data :
> - {
> - INIT_TASK_DATA(KERNEL_STACK_SIZE)
> - . = ALIGN(KERNEL_STACK_SIZE);
> - *(.data..init_irqstack)
> - DATA_DATA
> - *(.gnu.linkonce.d*)
> - CONSTRUCTORS
> - }
> - .data1 : { *(.data1) }
> - .ctors :
> - {
> - *(.ctors)
> - }
> - .dtors :
> - {
> - *(.dtors)
> - }
> -
> - .got : { *(.got.plt) *(.got) }
> - .dynamic : { *(.dynamic) }
> - .tdata : { *(.tdata .tdata.* .gnu.linkonce.td.*) }
> - .tbss : { *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon) }
> - /* We want the small data sections together, so single-instruction offsets
> - can access them all, and initialized data all before uninitialized, so
> - we can shorten the on-disk segment size. */
> - .sdata : { *(.sdata) }
> - _edata = .;
> - PROVIDE (edata = .);
> - . = ALIGN(PAGE_SIZE);
> - __bss_start = .;
> - PROVIDE(_bss_start = .);
> - SBSS(0)
> - BSS(0)
> - __bss_stop = .;
> - _end = .;
> - PROVIDE (end = .);
> -
> - STABS_DEBUG
> -
> - DWARF_DEBUG
> -
> - DISCARDS
> -}
> diff --git a/arch/um/kernel/vmlinux.lds.S b/arch/um/kernel/vmlinux.lds.S
> index 16e49bfa2b42..aaedd66772fa 100644
> --- a/arch/um/kernel/vmlinux.lds.S
> +++ b/arch/um/kernel/vmlinux.lds.S
> @@ -1,8 +1,87 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#include <asm/vmlinux.lds.h>
> +#include <asm/thread_info.h>
> +#include <asm/page.h>
> +#include <asm/thread_info.h>
> +#include <asm/cache.h>
> +#include <linux/export.h>
>
> -KERNEL_STACK_SIZE = 4096 * (1 << CONFIG_KERNEL_STACK_ORDER);
> +OUTPUT_FORMAT(ELF_FORMAT)
> +jiffies = jiffies_64;
>
> -#ifdef CONFIG_LD_SCRIPT_STATIC
> -#include "uml.lds.S"
> -#else
> -#include "dyn.lds.S"
> -#endif
> +
> +SECTIONS
> +{
> + __init_begin = . ;
> + HEAD_TEXT_SECTION
> + INIT_TEXT_SECTION(PAGE_SIZE)
> + INIT_DATA_SECTION(16)
> + PERCPU_SECTION(L1_CACHE_BYTES)
> + __init_end = . ;
> +
> + _stext = . ;
> + _text = . ;
> + .text : ALIGN(THREAD_SIZE)
> + {
> + __binary_start = . ;
> + TEXT_TEXT
> + SCHED_TEXT
> + LOCK_TEXT
> + CPUIDLE_TEXT
> + IRQENTRY_TEXT
> + SOFTIRQENTRY_TEXT
> + }
> + _etext = . ;
> +
> + .syscall_stub : ALIGN(PAGE_SIZE)
> + {
> + __syscall_stub_start = .;
> + *(.__syscall_stub*)
> + __syscall_stub_end = .;
> + }
> +
> + _sdata = . ;
> + RO_DATA(PAGE_SIZE)
> + RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
> + .data : ALIGN(THREAD_SIZE) { }
> +
> + EXCEPTION_TABLE(16)
> +
> + .uml.init_irqstack : ALIGN(THREAD_SIZE) {
> + *(.data..init_irqstack)
> + }
> +
> + .uml.setup.init : ALIGN(8) {
> + __uml_setup_start = .;
> + *(.uml.setup.init)
> + __uml_setup_end = .;
> + }
> +
> + .uml.help.init : ALIGN(8) {
> + __uml_help_start = .;
> + *(.uml.help.init)
> + __uml_help_end = .;
> + }
> +
> + .uml.postsetup.init : ALIGN(8) {
> + __uml_postsetup_start = .;
> + *(.uml.postsetup.init)
> + __uml_postsetup_end = .;
> + }
> +
> + .uml.exitcall : ALIGN(8) {
> + __uml_exitcall_begin = .;
> + *(.uml.exitcall.exit)
> + __uml_exitcall_end = .;
> + }
> + _edata = . ;
> +
> + BSS_SECTION(0, 0, 0)
> + _end = . ;
> +
> + STABS_DEBUG
> +
> + DWARF_DEBUG
> +
> + DISCARDS
> +}
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index e6e2d9e5ff48..903fc8053d07 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -102,36 +102,18 @@ vmlinux_link()
> strip_debug=-Wl,--strip-debug
> fi
>
> - if [ "${SRCARCH}" != "um" ]; then
> - objects="--whole-archive \
> - ${KBUILD_VMLINUX_OBJS} \
> - --no-whole-archive \
> - --start-group \
> - ${KBUILD_VMLINUX_LIBS} \
> - --end-group \
> - ${@}"
> -
> - ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
> - ${strip_debug#-Wl,} \
> - -o ${output} \
> - -T ${lds} ${objects}
> - else
> - objects="-Wl,--whole-archive \
> - ${KBUILD_VMLINUX_OBJS} \
> - -Wl,--no-whole-archive \
> - -Wl,--start-group \
> - ${KBUILD_VMLINUX_LIBS} \
> - -Wl,--end-group \
> - ${@}"
> -
> - ${CC} ${CFLAGS_vmlinux} \
> - ${strip_debug} \
> - -o ${output} \
> - -Wl,-T,${lds} \
> - ${objects} \
> - -lutil -lrt -lpthread
> - rm -f linux
> - fi
> + objects="--whole-archive \
> + ${KBUILD_VMLINUX_OBJS} \
> + --no-whole-archive \
> + --start-group \
> + ${KBUILD_VMLINUX_LIBS} \
> + --end-group \
> + ${@}"
> +
> + ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
> + ${strip_debug#-Wl,} \
> + -o ${output} \
> + -T ${lds} ${objects}
> }
>
> # generate .BTF typeinfo from DWARF debuginfo
> diff --git a/tools/um/Makefile b/tools/um/Makefile
> new file mode 100644
> index 000000000000..a63466ef7ef5
> --- /dev/null
> +++ b/tools/um/Makefile
> @@ -0,0 +1,72 @@
> +# Do not use make's built-in rules
> +# (this improves performance and avoids hard-to-debug behaviour);
> +# also do not print "Entering directory..." messages from make
> +.SUFFIXES:
> +MAKEFLAGS += -r --no-print-directory
> +
> +KCONFIG?=defconfig
> +
> +ifneq ($(silent),1)
> + ifneq ($(V),1)
> + QUIET_AUTOCONF = @echo ' AUTOCONF '$@;
> + Q = @
> + endif
> +endif
> +
> +PREFIX := /usr
> +
> +ifeq (,$(srctree))
> + srctree := $(patsubst %/,%,$(dir $(shell pwd)))
> + srctree := $(patsubst %/,%,$(dir $(srctree)))
> +endif
> +export srctree
> +
> +-include ../scripts/Makefile.include
> +
> +# OUTPUT fixup should be *after* include ../scripts/Makefile.include
> +ifneq ($(OUTPUT),)
> + OUTPUT := $(OUTPUT)/tools/um/
> +else
> + OUTPUT := $(CURDIR)/
> +endif
> +export OUTPUT
> +export objtree := $(OUTPUT)/../..
> +
> +
> +all:
> +
> +export CFLAGS += -I$(OUTPUT)/include -Iinclude -Wall -g -O2 -Wextra -fPIC \
> + -Wno-unused-parameter \
> + -Wno-missing-field-initializers -fno-strict-aliasing
> +
> +-include Targets
> +
> +TARGETS := $(progs-y:%=$(OUTPUT)%)
> +TARGETS += $(libs-y:%=$(OUTPUT)%)
> +all: $(TARGETS)
> +
> +# rule to build linux.o
> +$(OUTPUT)lib/linux.o:
> + $(Q)CFLAGS= $(MAKE) -C ../.. ARCH=um $(KOPT) $(KCONFIG)
> + $(Q)CFLAGS= $(MAKE) -C ../.. ARCH=um $(KOPT) install INSTALL_PATH=$(OUTPUT)
> +
> +$(OUTPUT)liblinux.a: $(OUTPUT)lib/linux.o $(OUTPUT)uml/liblinux-in.o
> + $(QUIET_AR)$(AR) -rc $@ $^
> +
> +# rule to link programs
> +$(OUTPUT)%: $(OUTPUT)%-in.o $(OUTPUT)liblinux.a
> + $(QUIET_LINK)$(CC) $(LDFLAGS) $(LDFLAGS_$(notdir $*)-y) -o $@ $^ $(LDLIBS) $(LDLIBS_$(notdir $*)-y)
> +
> +$(OUTPUT)%-in.o: FORCE
> + $(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(patsubst %/,%,$(dir $*)) obj=$(notdir $*)
> +
> +clean:
> + $(call QUIET_CLEAN, objects)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd'\
> + -delete -o -name '\.*.d' -delete
> + $(call QUIET_CLEAN, liblinux.a)$(RM) $(OUTPUT)/liblinux.a
> + $(call QUIET_CLEAN, $(TARGETS))$(RM) $(TARGETS)
> +
> +FORCE: ;
> +.PHONY: all clean FORCE
> +.IGNORE: clean
> +.NOTPARALLEL : lib/linux.o
> diff --git a/tools/um/Targets b/tools/um/Targets
> new file mode 100644
> index 000000000000..a4711f1ef422
> --- /dev/null
> +++ b/tools/um/Targets
> @@ -0,0 +1,4 @@
> +progs-y += uml/linux
> +LDLIBS_linux-y := -lrt -lpthread -lutil
> +LDFLAGS_linux-y := -no-pie -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
> +LDFLAGS_linux-$(UML_STATIC) += -static
> diff --git a/tools/um/uml/Build b/tools/um/uml/Build
> new file mode 100644
> index 000000000000..e69de29bb2d1
>
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
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