Commit 10ffe3db authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 build bits from Peter Anvin:
 "Various build-related minor bits.

  Most of this is work by David Woodhouse to be able to compile the
  early boot code with clang/llvm; we have also managed to push an
  actual -m16 option into gcc 4.9 so this makes us use that option if
  available instead of hacking it.

  The balance is a patch from Michael Davidson to the relocs program to
  help manual debugging.

  None of these should change the actual compiled binary with currently
  released compilers"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, build: Build 16-bit code with -m16 where possible
  x86, boot: Fix word-size assumptions in has_eflag() inline asm
  x86, boot: Use __attribute__((used)) to ensure videocard structs are emitted
  x86: Remove duplication of 16-bit CFLAGS
  x86, relocs: Add manual debug mode
parents f8a504c4 de3accda

arch/x86/Makefile

+22 −0
Original line number Diff line number Diff line
@@ -11,6 +11,28 @@ else 
        KBUILD_DEFCONFIG := $(ARCH)_defconfig

endif



# How to compile the 16-bit code.  Note we always compile for -march=i386;

# that way we can complain to the user if the CPU is insufficient.

#

# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For

# older versions of GCC, we need to play evil and unreliable tricks to

# attempt to ensure that our asm(".code16gcc") is first in the asm

# output.

CODE16GCC_CFLAGS := -m32 -include $(srctree)/arch/x86/boot/code16gcc.h \

		    $(call cc-option, -fno-toplevel-reorder,\

		      $(call cc-option, -fno-unit-at-a-time))

M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))



REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -D__KERNEL__ \

		   -DDISABLE_BRANCH_PROFILING \

		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \

		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \

		   -mno-mmx -mno-sse \

		   $(call cc-option, -ffreestanding) \

		   $(call cc-option, -fno-stack-protector) \

		   $(call cc-option, -mpreferred-stack-boundary=2)

export REALMODE_CFLAGS



# BITS is used as extension for files which are available in a 32 bit

# and a 64 bit version to simplify shared Makefiles.

# e.g.: obj-y += foo_$(BITS).o

arch/x86/boot/Makefile

+1 −14
Original line number Diff line number Diff line
@@ -51,20 +51,7 @@ $(obj)/cpustr.h: $(obj)/mkcpustr FORCE 


# ---------------------------------------------------------------------------



# How to compile the 16-bit code.  Note we always compile for -march=i386,

# that way we can complain to the user if the CPU is insufficient.

KBUILD_CFLAGS	:= $(USERINCLUDE) -m32 -g -Os -D_SETUP -D__KERNEL__ \

		   -DDISABLE_BRANCH_PROFILING \

		   -Wall -Wstrict-prototypes \

		   -march=i386 -mregparm=3 \

		   -include $(srctree)/$(src)/code16gcc.h \

		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \

		   -mno-mmx -mno-sse \

		   $(call cc-option, -ffreestanding) \

		   $(call cc-option, -fno-toplevel-reorder,\

		   $(call cc-option, -fno-unit-at-a-time)) \

		   $(call cc-option, -fno-stack-protector) \

		   $(call cc-option, -mpreferred-stack-boundary=2)

KBUILD_CFLAGS	:= $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP

KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__

GCOV_PROFILE := n

arch/x86/boot/cpuflags.c

+20 −5
Original line number Diff line number Diff line
@@ -28,20 +28,35 @@ static int has_fpu(void) 
	return fsw == 0 && (fcw & 0x103f) == 0x003f;

}



/*

 * For building the 16-bit code we want to explicitly specify 32-bit

 * push/pop operations, rather than just saying 'pushf' or 'popf' and

 * letting the compiler choose. But this is also included from the

 * compressed/ directory where it may be 64-bit code, and thus needs

 * to be 'pushfq' or 'popfq' in that case.

 */

#ifdef __x86_64__

#define PUSHF "pushfq"

#define POPF "popfq"

#else

#define PUSHF "pushfl"

#define POPF "popfl"

#endif



int has_eflag(unsigned long mask)

{

	unsigned long f0, f1;



	asm volatile("pushf	\n\t"

		     "pushf	\n\t"

	asm volatile(PUSHF "	\n\t"

		     PUSHF "	\n\t"

		     "pop %0	\n\t"

		     "mov %0,%1	\n\t"

		     "xor %2,%1	\n\t"

		     "push %1	\n\t"

		     "popf	\n\t"

		     "pushf	\n\t"

		     POPF "	\n\t"

		     PUSHF "	\n\t"

		     "pop %1	\n\t"

		     "popf"

		     POPF

		     : "=&r" (f0), "=&r" (f1)

		     : "ri" (mask));

arch/x86/boot/video.h

+1 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ struct card_info { 
	u16 xmode_n;		/* Size of unprobed mode range */

};



#define __videocard struct card_info __attribute__((section(".videocards")))

#define __videocard struct card_info __attribute__((used,section(".videocards")))

extern struct card_info video_cards[], video_cards_end[];



int mode_defined(u16 mode);	/* video.c */

arch/x86/realmode/rm/Makefile

+2 −15
Original line number Diff line number Diff line
@@ -64,20 +64,7 @@ $(obj)/realmode.relocs: $(obj)/realmode.elf FORCE 


# ---------------------------------------------------------------------------



# How to compile the 16-bit code.  Note we always compile for -march=i386,

# that way we can complain to the user if the CPU is insufficient.

KBUILD_CFLAGS	:= $(LINUXINCLUDE) -m32 -g -Os -D_SETUP -D__KERNEL__ -D_WAKEUP \

		   -I$(srctree)/arch/x86/boot \

		   -DDISABLE_BRANCH_PROFILING \

		   -Wall -Wstrict-prototypes \

		   -march=i386 -mregparm=3 \

		   -include $(srctree)/$(src)/../../boot/code16gcc.h \

		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \

		   -mno-mmx -mno-sse \

		   $(call cc-option, -ffreestanding) \

		   $(call cc-option, -fno-toplevel-reorder,\

		   $(call cc-option, -fno-unit-at-a-time)) \

		   $(call cc-option, -fno-stack-protector) \

		   $(call cc-option, -mpreferred-stack-boundary=2)

KBUILD_CFLAGS	:= $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \

		   -I$(srctree)/arch/x86/boot

KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__

GCOV_PROFILE := n

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