x86, setup: "glove box" BIOS calls -- infrastructure (7a734e7d) · Commits · 戴 / test

arch/x86/boot/Makefile

+3 −2

Original line number	Diff line number	Diff line
		@@ -26,9 +26,10 @@ targets := vmlinux.bin setup.bin setup.elf bzImage
		targets += fdimage fdimage144 fdimage288 image.iso mtools.conf
		subdir- := compressed

		setup-y += a20.o cmdline.o copy.o cpu.o cpucheck.o edd.o
		setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpucheck.o edd.o
		setup-y += header.o main.o mca.o memory.o pm.o pmjump.o
		setup-y += printf.o string.o tty.o video.o video-mode.o version.o
		setup-y += printf.o regs.o string.o tty.o video.o video-mode.o
		setup-y += version.o
		setup-$(CONFIG_X86_APM_BOOT) += apm.o

		# The link order of the video-*.o modules can matter. In particular,

arch/x86/boot/bioscall.S

0 → 100644

+82 −0

Original line number	Diff line number	Diff line
		/* -----------------------------------------------------------------------
		*
		* Copyright 2009 Intel Corporation; author H. Peter Anvin
		*
		* This file is part of the Linux kernel, and is made available under
		* the terms of the GNU General Public License version 2 or (at your
		* option) any later version; incorporated herein by reference.
		*
		* ----------------------------------------------------------------------- */

		/*
		* "Glove box" for BIOS calls. Avoids the constant problems with BIOSes
		* touching memory they shouldn't be.
		*/

		.code16
		.text
		.globl intcall
		.type intcall, @function
		intcall:
		/* Self-modify the INT instruction. Ugly, but works. */
		cmpb %al, 3f
		je 1f
		movb %al, 3f
		jmp 1f /* Synchronize pipeline */
		1:
		/* Save state */
		pushfl
		pushw %fs
		pushw %gs
		pushal

		/* Copy input state to stack frame */
		subw $44, %sp
		movw %dx, %si
		movw %sp, %di
		movw $11, %cx
		rep; movsd

		/* Pop full state from the stack */
		popal
		popw %gs
		popw %fs
		popw %es
		popw %ds
		popfl

		/* Actual INT */
		.byte 0xcd /* INT opcode */
		3: .byte 0

		/* Push full state to the stack */
		pushfl
		pushw %ds
		pushw %es
		pushw %fs
		pushw %gs
		pushal

		/* Re-establish C environment invariants */
		cld
		movzwl %sp, %esp
		movw %cs, %ax
		movw %ax, %ds
		movw %ax, %es

		/* Copy output state from stack frame */
		movw 68(%esp), %di /* Original %cx == 3rd argument */
		andw %di, %di
		jz 4f
		movw %sp, %si
		movw $11, %cx
		rep; movsd
		4: addw $44, %sp

		/* Restore state and return */
		popal
		popw %gs
		popw %fs
		popfl
		retl
		.size intcall, .-intcall

arch/x86/boot/boot.h

+48 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@
		*
		* Copyright (C) 1991, 1992 Linus Torvalds
		* Copyright 2007 rPath, Inc. - All Rights Reserved
		* Copyright 2009 Intel Corporation; author H. Peter Anvin
		*
		* This file is part of the Linux kernel, and is made available under
		* the terms of the GNU General Public License version 2.
		@@ -26,6 +27,7 @@
		#include <asm/setup.h>
		#include "bitops.h"
		#include <asm/cpufeature.h>
		#include <asm/processor-flags.h>

		/* Useful macros */
		#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
		@@ -241,6 +243,49 @@ int enable_a20(void);
		/* apm.c */
		int query_apm_bios(void);

		/* bioscall.c */
		struct biosregs {
		union {
		struct {
		u32 edi;
		u32 esi;
		u32 ebp;
		u32 _esp;
		u32 ebx;
		u32 edx;
		u32 ecx;
		u32 eax;
		u32 _fsgs;
		u32 _dses;
		u32 eflags;
		};
		struct {
		u16 di, hdi;
		u16 si, hsi;
		u16 bp, hbp;
		u16 _sp, _hsp;
		u16 bx, hbx;
		u16 dx, hdx;
		u16 cx, hcx;
		u16 ax, hax;
		u16 gs, fs;
		u16 es, ds;
		u16 flags, hflags;
		};
		struct {
		u8 dil, dih, edi2, edi3;
		u8 sil, sih, esi2, esi3;
		u8 bpl, bph, ebp2, ebp3;
		u8 _spl, _sph, _esp2, _esp3;
		u8 bl, bh, ebx2, ebx3;
		u8 dl, dh, edx2, edx3;
		u8 cl, ch, ecx2, ecx3;
		u8 al, ah, eax2, eax3;
		};
		};
		};
		void intcall(u8 int_no, const struct biosregs ireg, struct biosregs oreg);

		/* cmdline.c */
		int cmdline_find_option(const char option, char buffer, int bufsize);
		int cmdline_find_option_bool(const char *option);
		@@ -279,6 +324,9 @@ int sprintf(char buf, const char fmt, ...);
		int vsprintf(char buf, const char fmt, va_list args);
		int printf(const char *fmt, ...);

		/* regs.c */
		void initregs(struct biosregs *regs);

		/* string.c */
		int strcmp(const char str1, const char str2);
		size_t strnlen(const char *s, size_t maxlen);

arch/x86/boot/header.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -221,7 +221,7 @@ setup_data: .quad 0 # 64-bit physical pointer to

		# End of setup header #####################################################

		.section ".inittext", "ax"
		.section ".entrytext", "ax"
		start_of_setup:
		#ifdef SAFE_RESET_DISK_CONTROLLER
		# Reset the disk controller.

arch/x86/boot/regs.c

0 → 100644

+29 −0

Original line number	Diff line number	Diff line
		/* -----------------------------------------------------------------------
		*
		* Copyright 2009 Intel Corporation; author H. Peter Anvin
		*
		* This file is part of the Linux kernel, and is made available under
		* the terms of the GNU General Public License version 2 or (at your
		* option) any later version; incorporated herein by reference.
		*
		* ----------------------------------------------------------------------- */

		/*
		* Simple helper function for initializing a register set.
		*
		* Note that this sets EFLAGS_CF in the input register set; this
		* makes it easier to catch functions which do nothing but don't
		* explicitly set CF.
		*/

		#include "boot.h"

		void initregs(struct biosregs *reg)
		{
		memset(reg, 0, sizeof *reg);
		reg->eflags \|= X86_EFLAGS_CF;
		reg->ds = ds();
		reg->es = ds();
		reg->fs = fs();
		reg->gs = gs();
		}

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