/* * GRUB -- GRand Unified Bootloader * Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008,2009 Free Software Foundation, Inc. * * GRUB is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * GRUB is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with GRUB. If not, see . */ /* * Note: These functions defined in this file may be called from C. * Be careful of that you must not modify some registers. Quote * from gcc-2.95.2/gcc/config/i386/i386.h: 1 for registers not available across function calls. These must include the FIXED_REGISTERS and also any registers that can be used without being saved. The latter must include the registers where values are returned and the register where structure-value addresses are passed. Aside from that, you can include as many other registers as you like. ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg { 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 } */ /* * Note: GRUB is compiled with the options -mrtd and -mregparm=3. * So the first three arguments are passed in %eax, %edx, and %ecx, * respectively, and if a function has a fixed number of arguments * and the number is greater than three, the function must return * with "ret $N" where N is ((the number of arguments) - 3) * 4. */ #include #include #include #include #include #include #include #include #include #include #include #define ABS(x) ((x) - LOCAL (base) + GRUB_BOOT_MACHINE_KERNEL_ADDR + 0x200) .file "startup.S" .text /* Tell GAS to generate 16-bit instructions so that this code works in real mode. */ .code16 .globl start, _start start: _start: LOCAL (base): /* * Guarantee that "main" is loaded at 0x0:0x8200. */ #ifdef __APPLE__ ljmp $0, $(ABS(LOCAL (codestart)) - 0x10000) #else ljmp $0, $ABS(LOCAL (codestart)) #endif /* * Compatibility version number * * These MUST be at byte offset 6 and 7 of the executable * DO NOT MOVE !!! */ . = _start + 0x6 .byte GRUB_BOOT_VERSION_MAJOR, GRUB_BOOT_VERSION_MINOR /* * This is a special data area 8 bytes from the beginning. */ . = _start + 0x8 VARIABLE(grub_total_module_size) .long 0 VARIABLE(grub_kernel_image_size) .long 0 VARIABLE(grub_compressed_size) .long 0 VARIABLE(grub_install_dos_part) .long 0xFFFFFFFF VARIABLE(grub_install_bsd_part) .long 0xFFFFFFFF VARIABLE(grub_prefix) /* to be filled by grub-mkimage */ /* * Leave some breathing room for the prefix. */ . = _start + GRUB_KERNEL_MACHINE_DATA_END #ifdef APPLE_CC bss_start: .long 0 bss_end: .long 0 #endif /* * Support for booting GRUB from a Multiboot boot loader (e.g. GRUB itself). * This uses the a.out kludge to load raw binary to the area starting at 1MB, * and relocates itself after loaded. */ .p2align 2 /* force 4-byte alignment */ multiboot_header: /* magic */ .long 0x1BADB002 /* flags */ .long (1 << 16) /* checksum */ .long -0x1BADB002 - (1 << 16) /* header addr */ .long multiboot_header - _start + 0x100000 + 0x200 /* load addr */ .long 0x100000 /* load end addr */ .long 0 /* bss end addr */ .long 0 /* entry addr */ .long multiboot_entry - _start + 0x100000 + 0x200 multiboot_entry: .code32 /* obtain the boot device */ movl 12(%ebx), %edx movl $GRUB_MEMORY_MACHINE_PROT_STACK, %ebp movl %ebp, %esp /* relocate the code */ movl $(GRUB_KERNEL_MACHINE_RAW_SIZE + 0x200), %ecx addl EXT_C(grub_compressed_size) - _start + 0x100000 + 0x200, %ecx movl $0x100000, %esi movl $GRUB_BOOT_MACHINE_KERNEL_ADDR, %edi cld rep movsb /* jump to the real address */ movl $multiboot_trampoline, %eax jmp *%eax multiboot_trampoline: /* fill the boot information */ movl %edx, %eax shrl $8, %eax xorl %ebx, %ebx cmpb $0xFF, %ah je 1f movb %ah, %bl movl %ebx, EXT_C(grub_install_dos_part) 1: cmpb $0xFF, %al je 2f movb %al, %bl movl %ebx, EXT_C(grub_install_bsd_part) 2: shrl $24, %edx movb $0xFF, %dh /* enter the usual booting */ call prot_to_real .code16 /* the real mode code continues... */ LOCAL (codestart): cli /* we're not safe here! */ /* set up %ds, %ss, and %es */ xorw %ax, %ax movw %ax, %ds movw %ax, %ss movw %ax, %es /* set up the real mode/BIOS stack */ movl $GRUB_MEMORY_MACHINE_REAL_STACK, %ebp movl %ebp, %esp sti /* we're safe again */ /* save the boot drive */ ADDR32 movb %dl, EXT_C(grub_boot_drive) /* reset disk system (%ah = 0) */ int $0x13 /* transition to protected mode */ DATA32 call real_to_prot /* The ".code32" directive takes GAS out of 16-bit mode. */ .code32 incl %eax call EXT_C(grub_gate_a20) #ifdef ENABLE_LZMA movl $GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR, %edi movl $(_start + GRUB_KERNEL_MACHINE_RAW_SIZE), %esi pushl %edi pushl %esi movl EXT_C(grub_kernel_image_size), %ecx addl EXT_C(grub_total_module_size), %ecx subl $GRUB_KERNEL_MACHINE_RAW_SIZE, %ecx pushl %ecx leal (%edi, %ecx), %ebx call _LzmaDecodeA /* _LzmaDecodeA clears DF, so no need to run cld */ popl %ecx popl %edi popl %esi #endif /* copy back the decompressed part (except the modules) */ subl EXT_C(grub_total_module_size), %ecx rep movsb #if 0 /* copy modules before cleaning out the bss */ movl EXT_C(grub_total_module_size), %ecx movl EXT_C(grub_kernel_image_size), %esi addl %ecx, %esi addl $_start, %esi decl %esi movl $END_SYMBOL, %edi addl %ecx, %edi decl %edi std rep movsb #endif #ifdef APPLE_CC /* clean out the bss */ bss_start_abs = ABS (bss_start) bss_end_abs = ABS (bss_end) movl bss_start_abs, %edi /* compute the bss length */ movl bss_end_abs, %ecx subl %edi, %ecx #else /* clean out the bss */ movl $BSS_START_SYMBOL, %edi /* compute the bss length */ movl $END_SYMBOL, %ecx subl %edi, %ecx #endif /* clean out */ xorl %eax, %eax cld rep stosb /* * Call the start of main body of C code. */ call EXT_C(grub_main) /* * This is the area for all of the special variables. */ VARIABLE(grub_boot_drive) .byte 0 .p2align 2 /* force 4-byte alignment */ #include "../realmode.S" /* * grub_gate_a20(int on) * * Gate address-line 20 for high memory. * * This routine is probably overconservative in what it does, but so what? * * It also eats any keystrokes in the keyboard buffer. :-( */ FUNCTION(grub_gate_a20) movl %eax, %edx gate_a20_test_current_state: /* first of all, test if already in a good state */ call gate_a20_check_state cmpb %al, %dl jnz gate_a20_try_bios ret gate_a20_try_bios: /* second, try a BIOS call */ pushl %ebp call prot_to_real .code16 movw $0x2400, %ax testb %dl, %dl jz 1f incw %ax 1: int $0x15 DATA32 call real_to_prot .code32 popl %ebp call gate_a20_check_state cmpb %al, %dl jnz gate_a20_try_system_control_port_a ret gate_a20_try_system_control_port_a: /* * In macbook, the keyboard test would hang the machine, so we move * this forward. */ /* fourth, try the system control port A */ inb $0x92 andb $(~0x03), %al testb %dl, %dl jz 6f orb $0x02, %al 6: outb $0x92 /* When turning off Gate A20, do not check the state strictly, because a failure is not fatal usually, and Gate A20 is always on some modern machines. */ testb %dl, %dl jz 7f call gate_a20_check_state cmpb %al, %dl jnz gate_a20_try_keyboard_controller 7: ret gate_a20_flush_keyboard_buffer: inb $0x64 andb $0x02, %al jnz gate_a20_flush_keyboard_buffer 2: inb $0x64 andb $0x01, %al jz 3f inb $0x60 jmp 2b 3: ret gate_a20_try_keyboard_controller: /* third, try the keyboard controller */ call gate_a20_flush_keyboard_buffer movb $0xd1, %al outb $0x64 4: inb $0x64 andb $0x02, %al jnz 4b movb $0xdd, %al testb %dl, %dl jz 5f orb $0x02, %al 5: outb $0x60 call gate_a20_flush_keyboard_buffer /* output a dummy command (USB keyboard hack) */ movb $0xff, %al outb $0x64 call gate_a20_flush_keyboard_buffer call gate_a20_check_state cmpb %al, %dl /* everything failed, so restart from the beginning */ jnz gate_a20_try_bios ret gate_a20_check_state: /* iterate the checking for a while */ movl $100, %ecx 1: call 3f cmpb %al, %dl jz 2f loop 1b 2: ret 3: pushl %ebx pushl %ecx xorl %eax, %eax /* compare the byte at 0x8000 with that at 0x108000 */ movl $GRUB_BOOT_MACHINE_KERNEL_ADDR, %ebx pushl %ebx /* save the original byte in CL */ movb (%ebx), %cl /* store the value at 0x108000 in AL */ addl $0x100000, %ebx movb (%ebx), %al /* try to set one less value at 0x8000 */ popl %ebx movb %al, %ch decb %ch movb %ch, (%ebx) /* serialize */ outb %al, $0x80 outb %al, $0x80 /* obtain the value at 0x108000 in CH */ pushl %ebx addl $0x100000, %ebx movb (%ebx), %ch /* this result is 1 if A20 is on or 0 if it is off */ subb %ch, %al xorb $1, %al /* restore the original */ popl %ebx movb %cl, (%ebx) popl %ecx popl %ebx ret #ifdef ENABLE_LZMA #include "lzma_decode.S" #endif /* * The code beyond this point is compressed. Assert that the uncompressed * code fits GRUB_KERNEL_MACHINE_RAW_SIZE. */ . = _start + GRUB_KERNEL_MACHINE_RAW_SIZE /* * This next part is sort of evil. It takes advantage of the * byte ordering on the x86 to work in either 16-bit or 32-bit * mode, so think about it before changing it. */ FUNCTION(grub_hard_stop) hlt jmp EXT_C(grub_hard_stop) /* * grub_stop_floppy() * * Stop the floppy drive from spinning, so that other software is * jumped to with a known state. */ FUNCTION(grub_stop_floppy) movw $0x3F2, %dx xorb %al, %al outb %al, %dx ret /* * grub_exit() * * Exit the system. */ FUNCTION(grub_exit) call prot_to_real .code16 /* Tell the BIOS a boot failure. If this does not work, reboot. */ int $0x18 jmp cold_reboot .code32 /* * grub_halt(int no_apm) * * Halt the system, using APM if possible. If NO_APM is true, don't use * APM even if it is available. */ FUNCTION(grub_halt) /* see if zero */ testl %eax, %eax jnz EXT_C(grub_stop) call prot_to_real .code16 /* detect APM */ movw $0x5300, %ax xorw %bx, %bx int $0x15 jc EXT_C(grub_hard_stop) /* don't check %bx for buggy BIOSes... */ /* disconnect APM first */ movw $0x5304, %ax xorw %bx, %bx int $0x15 /* connect APM */ movw $0x5301, %ax xorw %bx, %bx int $0x15 jc EXT_C(grub_hard_stop) /* set APM protocol level - 1.1 or bust. (this covers APM 1.2 also) */ movw $0x530E, %ax xorw %bx, %bx movw $0x0101, %cx int $0x15 jc EXT_C(grub_hard_stop) /* set the power state to off */ movw $0x5307, %ax movw $1, %bx movw $3, %cx int $0x15 /* shouldn't reach here */ jmp EXT_C(grub_hard_stop) .code32 /* * void grub_chainloader_real_boot (int drive, void *part_addr) * * This starts another boot loader. */ FUNCTION(grub_chainloader_real_boot) pushl %edx pushl %eax call EXT_C(grub_dl_unload_all) /* Turn off Gate A20 */ xorl %eax, %eax call EXT_C(grub_gate_a20) /* set up to pass boot drive */ popl %edx /* ESI must point to a partition table entry */ popl %esi call prot_to_real .code16 ljmp $0, $GRUB_MEMORY_MACHINE_BOOT_LOADER_ADDR .code32 #include "../loader.S" /* * int grub_biosdisk_rw_int13_extensions (int ah, int drive, void *dap) * * Call IBM/MS INT13 Extensions (int 13 %ah=AH) for DRIVE. DAP * is passed for disk address packet. If an error occurs, return * non-zero, otherwise zero. */ FUNCTION(grub_biosdisk_rw_int13_extensions) pushl %ebp pushl %esi /* compute the address of disk_address_packet */ movw %cx, %si xorw %cx, %cx shrl $4, %ecx /* save the segment to cx */ /* ah */ movb %al, %dh /* enter real mode */ call prot_to_real .code16 movb %dh, %ah movw %cx, %ds int $0x13 /* do the operation */ movb %ah, %dl /* save return value */ /* back to protected mode */ DATA32 call real_to_prot .code32 movb %dl, %al /* return value in %eax */ popl %esi popl %ebp ret /* * int grub_biosdisk_rw_standard (int ah, int drive, int coff, int hoff, * int soff, int nsec, int segment) * * Call standard and old INT13 (int 13 %ah=AH) for DRIVE. Read/write * NSEC sectors from COFF/HOFF/SOFF into SEGMENT. If an error occurs, * return non-zero, otherwise zero. */ FUNCTION(grub_biosdisk_rw_standard) pushl %ebp movl %esp, %ebp pushl %ebx pushl %edi pushl %esi /* set up CHS information */ /* set %ch to low eight bits of cylinder */ xchgb %cl, %ch /* set bits 6-7 of %cl to high two bits of cylinder */ shlb $6, %cl /* set bits 0-5 of %cl to sector */ addb 0xc(%ebp), %cl /* set %dh to head */ movb 0x8(%ebp), %dh /* set %ah to AH */ movb %al, %ah /* set %al to NSEC */ movb 0x10(%ebp), %al /* save %ax in %di */ movw %ax, %di /* save SEGMENT in %bx */ movw 0x14(%ebp), %bx /* enter real mode */ call prot_to_real .code16 movw %bx, %es xorw %bx, %bx movw $3, %si /* attempt at least three times */ 1: movw %di, %ax int $0x13 /* do the operation */ jnc 2f /* check if successful */ movb %ah, %bl /* save return value */ /* if fail, reset the disk system */ xorw %ax, %ax int $0x13 decw %si cmpw $0, %si je 2f xorb %bl, %bl jmp 1b /* retry */ 2: /* back to protected mode */ DATA32 call real_to_prot .code32 movb %bl, %al /* return value in %eax */ popl %esi popl %edi popl %ebx popl %ebp ret $(4 * 4) /* * int grub_biosdisk_check_int13_extensions (int drive) * * Check if LBA is supported for DRIVE. If it is supported, then return * the major version of extensions, otherwise zero. */ FUNCTION(grub_biosdisk_check_int13_extensions) pushl %ebp pushl %ebx /* drive */ movb %al, %dl /* enter real mode */ call prot_to_real .code16 movb $0x41, %ah movw $0x55aa, %bx int $0x13 /* do the operation */ /* check the result */ jc 1f cmpw $0xaa55, %bx jne 1f movb %ah, %bl /* save the major version into %bl */ /* check if AH=0x42 is supported */ andw $1, %cx jnz 2f 1: xorb %bl, %bl 2: /* back to protected mode */ DATA32 call real_to_prot .code32 movb %bl, %al /* return value in %eax */ popl %ebx popl %ebp ret /* * int grub_biosdisk_get_cdinfo_int13_extensions (int drive, void *cdrp) * * Return the cdrom information of DRIVE in CDRP. If an error occurs, * then return non-zero, otherwise zero. */ FUNCTION(grub_biosdisk_get_cdinfo_int13_extensions) movw $0x4B01, %cx jmp 1f /* * int grub_biosdisk_get_diskinfo_int13_extensions (int drive, void *drp) * * Return the geometry of DRIVE in a drive parameters, DRP. If an error * occurs, then return non-zero, otherwise zero. */ FUNCTION(grub_biosdisk_get_diskinfo_int13_extensions) movb $0x48, %ch 1: pushl %ebp pushl %ebx pushl %esi /* compute the address of drive parameters */ movw %dx, %si andl $0xf, %esi shrl $4, %edx movw %dx, %bx /* save the segment into %bx */ /* drive */ movb %al, %dl /* enter real mode */ call prot_to_real .code16 movw %cx, %ax movw %bx, %ds int $0x13 /* do the operation */ jc noclean /* Clean return value if carry isn't set to workaround some buggy BIOSes. */ xor %ax, %ax noclean: movb %ah, %bl /* save return value in %bl */ /* back to protected mode */ DATA32 call real_to_prot .code32 movb %bl, %al /* return value in %eax */ popl %esi popl %ebx popl %ebp ret /* * int grub_biosdisk_get_diskinfo_standard (int drive, * unsigned long *cylinders, * unsigned long *heads, * unsigned long *sectors) * * Return the geometry of DRIVE in CYLINDERS, HEADS and SECTORS. If an * error occurs, then return non-zero, otherwise zero. */ FUNCTION(grub_biosdisk_get_diskinfo_standard) pushl %ebp pushl %ebx pushl %edi /* push CYLINDERS */ pushl %edx /* push HEADS */ pushl %ecx /* SECTORS is on the stack */ /* drive */ movb %al, %dl /* enter real mode */ call prot_to_real .code16 movb $0x8, %ah int $0x13 /* do the operation */ jc noclean2 /* Clean return value if carry isn't set to workaround some buggy BIOSes. */ xor %ax, %ax noclean2: /* check if successful */ testb %ah, %ah jnz 1f /* bogus BIOSes may not return an error number */ testb $0x3f, %cl /* 0 sectors means no disk */ jnz 1f /* if non-zero, then succeed */ /* XXX 0x60 is one of the unused error numbers */ movb $0x60, %ah 1: movb %ah, %bl /* save return value in %bl */ /* back to protected mode */ DATA32 call real_to_prot .code32 /* pop HEADS */ popl %edi movb %dh, %al incl %eax /* the number of heads is counted from zero */ movl %eax, (%edi) /* pop CYLINDERS */ popl %edi movb %ch, %al movb %cl, %ah shrb $6, %ah /* the number of cylinders is counted from zero */ incl %eax movl %eax, (%edi) /* SECTORS */ movl 0x10(%esp), %edi andb $0x3f, %cl movzbl %cl, %eax movl %eax, (%edi) xorl %eax, %eax movb %bl, %al /* return value in %eax */ popl %edi popl %ebx popl %ebp ret $4 /* * int grub_biosdisk_get_num_floppies (void) */ FUNCTION(grub_biosdisk_get_num_floppies) pushl %ebp xorl %edx, %edx call prot_to_real .code16 /* reset the disk system first */ int $0x13 1: stc /* call GET DISK TYPE */ movb $0x15, %ah int $0x13 jc 2f /* check if this drive exists */ testb $0x3, %ah jz 2f incb %dl cmpb $2, %dl jne 1b 2: DATA32 call real_to_prot .code32 movl %edx, %eax popl %ebp ret /* * * grub_get_memsize(i) : return the memory size in KB. i == 0 for conventional * memory, i == 1 for extended memory * BIOS call "INT 12H" to get conventional memory size * BIOS call "INT 15H, AH=88H" to get extended memory size * Both have the return value in AX. * */ FUNCTION(grub_get_memsize) pushl %ebp movl %eax, %edx call prot_to_real /* enter real mode */ .code16 testl %edx, %edx jnz xext int $0x12 jmp xdone xext: movb $0x88, %ah int $0x15 xdone: movw %ax, %dx DATA32 call real_to_prot .code32 movw %dx, %ax popl %ebp ret /* * * grub_get_eisa_mmap() : return packed EISA memory map, lower 16 bits is * memory between 1M and 16M in 1K parts, upper 16 bits is * memory above 16M in 64K parts. If error, return zero. * BIOS call "INT 15H, AH=E801H" to get EISA memory map, * AX = memory between 1M and 16M in 1K parts. * BX = memory above 16M in 64K parts. * */ FUNCTION(grub_get_eisa_mmap) pushl %ebp pushl %ebx call prot_to_real /* enter real mode */ .code16 movw $0xe801, %ax int $0x15 shll $16, %ebx movw %ax, %bx DATA32 call real_to_prot .code32 cmpb $0x86, %bh je xnoteisa movl %ebx, %eax xnoteisa: popl %ebx popl %ebp ret /* * * grub_get_mmap_entry(addr, cont) : address and old continuation value (zero to * start), for the Query System Address Map BIOS call. * * Sets the first 4-byte int value of "addr" to the size returned by * the call. If the call fails, sets it to zero. * * Returns: new (non-zero) continuation value, 0 if done. */ FUNCTION(grub_get_mmap_entry) pushl %ebp pushl %ebx pushl %edi pushl %esi /* push ADDR */ pushl %eax /* place address (+4) in ES:DI */ addl $4, %eax movl %eax, %edi andl $0xf, %edi shrl $4, %eax movl %eax, %esi /* set continuation value */ movl %edx, %ebx /* set default maximum buffer size */ movl $0x14, %ecx /* set EDX to 'SMAP' */ movl $0x534d4150, %edx call prot_to_real /* enter real mode */ .code16 movw %si, %es movl $0xe820, %eax int $0x15 DATA32 jc xnosmap cmpl $0x534d4150, %eax jne xnosmap cmpl $0x14, %ecx jl xnosmap cmpl $0x400, %ecx jg xnosmap jmp xsmap xnosmap: xorl %ecx, %ecx /* Apple's cc jumps few bytes before the correct label in this context. Hence nops. */ #ifdef APPLE_CC nop nop nop nop nop nop #endif xsmap: DATA32 call real_to_prot .code32 /* write length of buffer (zero if error) into ADDR */ popl %eax movl %ecx, (%eax) /* set return value to continuation */ movl %ebx, %eax popl %esi popl %edi popl %ebx popl %ebp ret /* * void grub_console_putchar (const struct grub_unicode_glyph *c) * * Put the character C on the console. Because GRUB wants to write a * character with an attribute, this implementation is a bit tricky. * If C is a control character (CR, LF, BEL, BS), use INT 10, AH = 0Eh * (TELETYPE OUTPUT). Otherwise, save the original position, put a space, * save the current position, restore the original position, write the * character and the attribute, and restore the current position. * * The reason why this is so complicated is that there is no easy way to * get the height of the screen, and the TELETYPE OUTPUT BIOS call doesn't * support setting a background attribute. */ FUNCTION(grub_console_putchar) /* Retrieve the base character. */ movl 0(%edx), %edx pusha movb EXT_C(grub_console_cur_color), %bl call prot_to_real .code16 movb %dl, %al xorb %bh, %bh /* use teletype output if control character */ cmpb $0x7, %al je 1f cmpb $0x8, %al je 1f cmpb $0xa, %al je 1f cmpb $0xd, %al je 1f /* save the character and the attribute on the stack */ pushw %ax pushw %bx /* get the current position */ movb $0x3, %ah int $0x10 /* check the column with the width */ cmpb $79, %dl jl 2f /* print CR and LF, if next write will exceed the width */ movw $0x0e0d, %ax int $0x10 movb $0x0a, %al int $0x10 /* get the current position */ movb $0x3, %ah int $0x10 2: /* restore the character and the attribute */ popw %bx popw %ax /* write the character with the attribute */ movb $0x9, %ah movw $1, %cx int $0x10 /* move the cursor forward */ incb %dl movb $0x2, %ah int $0x10 jmp 3f 1: movw $1, %bx movb $0xe, %ah int $0x10 3: DATA32 call real_to_prot .code32 popa ret LOCAL(bypass_table): .word 0x0100 | '\e',0x0f00 | '\t', 0x0e00 | '\b', 0x1c00 | '\r' .word 0x1c00 | '\n' LOCAL(bypass_table_end): /* * int grub_console_getkey (void) * if there is a character pending, return it; otherwise return -1 * BIOS call "INT 16H Function 01H" to check whether a character is pending * Call with %ah = 0x1 * Return: * If key waiting to be input: * %ah = keyboard scan code * %al = ASCII character * Zero flag = clear * else * Zero flag = set * BIOS call "INT 16H Function 00H" to read character from keyboard * Call with %ah = 0x0 * Return: %ah = keyboard scan code * %al = ASCII character */ FUNCTION(grub_console_getkey) pushl %ebp call prot_to_real .code16 /* * Due to a bug in apple's bootcamp implementation, INT 16/AH = 0 would * cause the machine to hang at the second keystroke. However, we can * work around this problem by ensuring the presence of keystroke with * INT 16/AH = 1 before calling INT 16/AH = 0. */ movb $1, %ah int $0x16 jz notpending movb $0, %ah int $0x16 xorl %edx, %edx movw %ax, %dx /* real_to_prot uses %eax */ DATA32 call real_to_prot .code32 movl $0xff, %eax testl %eax, %edx jz 1f andl %edx, %eax cmp %eax, 0x20 ja 2f movl %edx, %eax leal LOCAL(bypass_table), %esi movl $((LOCAL(bypass_table_end) - LOCAL(bypass_table)) / 2), %ecx repne cmpsw jz 3f addl $('a' - 1 | GRUB_TERM_CTRL), %eax jmp 2f 3: andl $0xff, %eax jmp 2f 1: movl %edx, %eax shrl $8, %eax orl $GRUB_TERM_EXTENDED, %eax 2: popl %ebp ret notpending: .code16 DATA32 call real_to_prot .code32 #if GRUB_TERM_NO_KEY != -1 #error Fix this asm code #endif decl %eax jmp 2b /* * grub_uint16_t grub_console_getxy (void) * BIOS call "INT 10H Function 03h" to get cursor position * Call with %ah = 0x03 * %bh = page * Returns %ch = starting scan line * %cl = ending scan line * %dh = row (0 is top) * %dl = column (0 is left) */ FUNCTION(grub_console_getxy) pushl %ebp pushl %ebx /* save EBX */ call prot_to_real .code16 xorb %bh, %bh /* set page to 0 */ movb $0x3, %ah int $0x10 /* get cursor position */ DATA32 call real_to_prot .code32 movb %dl, %ah movb %dh, %al popl %ebx popl %ebp ret /* * void grub_console_gotoxy(grub_uint8_t x, grub_uint8_t y) * BIOS call "INT 10H Function 02h" to set cursor position * Call with %ah = 0x02 * %bh = page * %dh = row (0 is top) * %dl = column (0 is left) */ FUNCTION(grub_console_gotoxy) pushl %ebp pushl %ebx /* save EBX */ movb %cl, %dh /* %dh = y */ /* %dl = x */ call prot_to_real .code16 xorb %bh, %bh /* set page to 0 */ movb $0x2, %ah int $0x10 /* set cursor position */ DATA32 call real_to_prot .code32 popl %ebx popl %ebp ret /* * void grub_console_cls (void) * BIOS call "INT 10H Function 09h" to write character and attribute * Call with %ah = 0x09 * %al = (character) * %bh = (page number) * %bl = (attribute) * %cx = (number of times) */ FUNCTION(grub_console_cls) pushl %ebp pushl %ebx /* save EBX */ call prot_to_real .code16 /* move the cursor to the beginning */ movb $0x02, %ah xorb %bh, %bh xorw %dx, %dx int $0x10 /* write spaces to the entire screen */ movw $0x0920, %ax movw $0x07, %bx movw $(80 * 25), %cx int $0x10 /* move back the cursor */ movb $0x02, %ah int $0x10 DATA32 call real_to_prot .code32 popl %ebx popl %ebp ret /* * void grub_console_setcursor (int on) * BIOS call "INT 10H Function 01h" to set cursor type * Call with %ah = 0x01 * %ch = cursor starting scanline * %cl = cursor ending scanline */ console_cursor_state: .byte 1 console_cursor_shape: .word 0 FUNCTION(grub_console_setcursor) pushl %ebp pushl %ebx /* push ON */ pushl %edx /* check if the standard cursor shape has already been saved */ movw console_cursor_shape, %ax testw %ax, %ax jne 1f call prot_to_real .code16 movb $0x03, %ah xorb %bh, %bh int $0x10 DATA32 call real_to_prot .code32 movw %cx, console_cursor_shape 1: /* set %cx to the designated cursor shape */ movw $0x2000, %cx popl %eax testl %eax, %eax jz 2f movw console_cursor_shape, %cx 2: call prot_to_real .code16 movb $0x1, %ah int $0x10 DATA32 call real_to_prot .code32 popl %ebx popl %ebp ret /* * grub_get_rtc() * return the real time in ticks, of which there are about * 18-20 per second */ FUNCTION(grub_get_rtc) pushl %ebp call prot_to_real /* enter real mode */ .code16 /* %ax is already zero */ int $0x1a DATA32 call real_to_prot .code32 movl %ecx, %eax shll $16, %eax movw %dx, %ax popl %ebp ret /* * unsigned char grub_vga_set_mode (unsigned char mode) */ FUNCTION(grub_vga_set_mode) pushl %ebp pushl %ebx movl %eax, %ecx call prot_to_real .code16 /* get current mode */ xorw %bx, %bx movb $0x0f, %ah int $0x10 movb %al, %dl /* set the new mode */ movb %cl, %al xorb %ah, %ah int $0x10 DATA32 call real_to_prot .code32 movb %dl, %al popl %ebx popl %ebp ret /* * grub_vbe_bios_status_t grub_vbe_get_controller_info (struct grub_vbe_info_block *controller_info) * * Register allocations for parameters: * %eax *controller_info */ FUNCTION(grub_vbe_bios_get_controller_info) pushl %ebp pushl %edi pushl %edx movw %ax, %di /* Store *controller_info to %edx:%di. */ xorw %ax, %ax shrl $4, %eax mov %eax, %edx /* prot_to_real destroys %eax. */ call prot_to_real .code16 pushw %es movw %dx, %es /* *controller_info is now on %es:%di. */ movw $0x4f00, %ax int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ popw %es DATA32 call real_to_prot .code32 movl %edx, %eax andl $0x0FFFF, %eax /* Return value in %eax. */ pop %edx popl %edi popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_get_mode_info (grub_uint32_t mode, * struct grub_vbe_mode_info_block *mode_info) * * Register allocations for parameters: * %eax mode * %edx *mode_info */ FUNCTION(grub_vbe_bios_get_mode_info) pushl %ebp pushl %edi movl %eax, %ecx /* Store mode number to %ecx. */ movw %dx, %di /* Store *mode_info to %edx:%di. */ xorw %dx, %dx shrl $4, %edx call prot_to_real .code16 pushw %es movw %dx, %es /* *mode_info is now on %es:%di. */ movw $0x4f01, %ax int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ popw %es DATA32 call real_to_prot .code32 movl %edx, %eax andl $0x0FFFF, %eax /* Return value in %eax. */ popl %edi popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_set_mode (grub_uint32_t mode, * struct grub_vbe_crtc_info_block *crtc_info) * * Register allocations for parameters: * %eax mode * %edx *crtc_info */ FUNCTION(grub_vbe_bios_set_mode) pushl %ebp pushl %ebx pushl %edi movl %eax, %ebx /* Store mode in %ebx. */ movw %dx, %di /* Store *crtc_info to %edx:%di. */ xorw %dx, %dx shrl $4, %edx call prot_to_real .code16 pushw %es movw %dx, %es /* *crtc_info is now on %es:%di. */ movw $0x4f02, %ax int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ popw %es DATA32 call real_to_prot .code32 movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edi popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_get_mode (grub_uint32_t *mode) * * Register allocations for parameters: * %eax *mode */ FUNCTION(grub_vbe_bios_get_mode) pushl %ebp pushl %ebx pushl %edi pushl %edx pushl %eax /* Push *mode to stack. */ call prot_to_real .code16 movw $0x4f03, %ax int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 popl %edi /* Pops *mode from stack to %edi. */ andl $0xFFFF, %ebx movl %ebx, (%edi) movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edx popl %edi popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_getset_dac_palette_width (int set, int *dac_mask_size) * * Register allocations for parameters: * %eax set * %edx *dac_mask_size */ FUNCTION(grub_vbe_bios_getset_dac_palette_width) pushl %ebp pushl %ebx xorl %ebx, %ebx /* If we only want to fetch the value, set %bl to 1. */ testl %eax, %eax jne 1f incb %bl 1: /* Put desired width in %bh. */ movl (%edx), %eax movb %al, %bh call prot_to_real .code16 movw $0x4f08, %ax int $0x10 movw %ax, %cx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 /* Move result back to *dac_mask_size. */ xorl %eax, %eax movb %bh, %al movl %eax, (%edx) /* Return value in %eax. */ movw %cx, %ax popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_set_memory_window (grub_uint32_t window, * grub_uint32_t position); * * Register allocations for parameters: * %eax window * %edx position */ FUNCTION(grub_vbe_bios_set_memory_window) pushl %ebp pushl %ebx movl %eax, %ebx call prot_to_real .code16 movw $0x4f05, %ax andw $0x00ff, %bx /* BL = window, BH = 0, Set memory window. */ int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_get_memory_window (grub_uint32_t window, * grub_uint32_t *position); * * Register allocations for parameters: * %eax window * %edx *position */ FUNCTION(grub_vbe_bios_get_memory_window) pushl %ebp pushl %ebx pushl %edi pushl %edx /* Push *position to stack. */ movl %eax, %ebx /* Store window in %ebx. */ call prot_to_real .code16 movw $0x4f05, %ax andw $0x00ff, %bx /* BL = window. */ orw $0x0100, %bx /* BH = 1, Get memory window. */ int $0x10 movw %ax, %bx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 popl %edi /* pops *position from stack to %edi. */ andl $0xFFFF, %edx movl %edx, (%edi) /* Return position to caller. */ movw %bx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edi popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_set_scanline_length (grub_uint32_t length) * * Register allocations for parameters: * %eax length */ FUNCTION(grub_vbe_bios_set_scanline_length) pushl %ebp pushl %ebx pushl %edx movl %eax, %ecx /* Store length in %ecx. */ call prot_to_real .code16 movw $0x4f06, %ax movw $0x0002, %bx /* BL = 2, Set Scan Line in Bytes. */ int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edx popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_get_scanline_length (grub_uint32_t *length) * * Register allocations for parameters: * %eax *length */ FUNCTION(grub_vbe_bios_get_scanline_length) pushl %ebp pushl %ebx pushl %edi pushl %edx /* Push *length to stack. */ call prot_to_real .code16 movw $0x4f06, %ax movw $0x0001, %bx /* BL = 1, Get Scan Line Length (in bytes). */ int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 popl %edi /* Pops *length from stack to %edi. */ andl $0xFFFF, %ebx movl %ebx, (%edi) /* Return length to caller. */ movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edi popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_set_display_start (grub_uint32_t x, * grub_uint32_t y) * * Register allocations for parameters: * %eax x * %edx y */ FUNCTION(grub_vbe_bios_set_display_start) pushl %ebp pushl %ebx movl %eax, %ecx /* Store x in %ecx. */ call prot_to_real .code16 movw $0x4f07, %ax movw $0x0080, %bx /* BL = 80h, Set Display Start during Vertical Retrace. */ int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_get_display_start (grub_uint32_t *x, * grub_uint32_t *y) * * Register allocations for parameters: * %eax *x * %edx *y */ FUNCTION(grub_vbe_bios_get_display_start) pushl %ebp pushl %ebx pushl %edi pushl %eax /* Push *x to stack. */ pushl %edx /* Push *y to stack. */ call prot_to_real .code16 movw $0x4f07, %ax movw $0x0001, %bx /* BL = 1, Get Display Start. */ int $0x10 movw %ax, %bx /* real_to_prot destroys %eax. */ DATA32 call real_to_prot .code32 popl %edi /* Pops *y from stack to %edi. */ andl $0xFFFF, %edx movl %edx, (%edi) /* Return y-position to caller. */ popl %edi /* Pops *x from stack to %edi. */ andl $0xFFFF, %ecx movl %ecx, (%edi) /* Return x-position to caller. */ movw %bx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edi popl %ebx popl %ebp ret /* * grub_vbe_status_t grub_vbe_bios_set_palette_data (grub_uint32_t color_count, * grub_uint32_t start_index, * struct grub_vbe_palette_data *palette_data) * * Register allocations for parameters: * %eax color_count * %edx start_index * %ecx *palette_data */ FUNCTION(grub_vbe_bios_set_palette_data) pushl %ebp pushl %ebx pushl %edi movl %eax, %ebx /* Store color_count in %ebx. */ movw %cx, %di /* Store *palette_data to %ecx:%di. */ xorw %cx, %cx shrl $4, %ecx call prot_to_real .code16 pushw %es movw %cx, %es /* *palette_data is now on %es:%di. */ movw %bx, %cx /* color_count is now on %cx. */ movw $0x4f09, %ax xorw %bx, %bx /* BL = 0, Set Palette Data. */ int $0x10 movw %ax, %dx /* real_to_prot destroys %eax. */ popw %es DATA32 call real_to_prot .code32 movw %dx, %ax andl $0xFFFF, %eax /* Return value in %eax. */ popl %edi popl %ebx popl %ebp ret pxe_rm_entry: .long 0 /* * struct grub_pxenv *grub_pxe_scan (void); */ FUNCTION(grub_pxe_scan) pushl %ebp pushl %ebx xorl %ebx, %ebx xorl %ecx, %ecx call prot_to_real .code16 pushw %es movw $0x5650, %ax int $0x1A cmpw $0x564E, %ax jnz 1f cmpl $0x4E455850, %es:(%bx) /* PXEN(V+) */ jnz 1f cmpw $0x201, %es:6(%bx) /* API version */ jb 1f lesw %es:0x28(%bx), %bx /* !PXE structure */ cmpl $0x45585021, %es:(%bx) /* !PXE */ jnz 1f movw %es, %cx jmp 2f 1: xorw %bx, %bx xorw %cx, %cx 2: popw %es DATA32 call real_to_prot .code32 xorl %eax, %eax leal (%eax, %ecx, 4), %ecx leal (%ebx, %ecx, 4), %eax /* eax = ecx * 16 + ebx */ orl %eax, %eax jz 1f movl 0x10(%eax), %ecx movl %ecx, pxe_rm_entry 1: popl %ebx popl %ebp ret /* * int grub_pxe_call (int func, void* data); */ FUNCTION(grub_pxe_call) pushl %ebp movl %esp, %ebp pushl %esi pushl %edi pushl %ebx movl %eax, %ecx movl %edx, %eax andl $0xF, %eax shrl $4, %edx shll $16, %edx addl %eax, %edx movl pxe_rm_entry, %ebx call prot_to_real .code16 pushl %ebx pushl %edx pushw %cx movw %sp, %bx lcall *%ss:6(%bx) cld addw $10, %sp movw %ax, %cx DATA32 call real_to_prot .code32 movzwl %cx, %eax popl %ebx popl %edi popl %esi popl %ebp ret