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Diffstat (limited to 'arch/i386/boot/setup.S')
| -rw-r--r-- | arch/i386/boot/setup.S | 1075 |
1 files changed, 0 insertions, 1075 deletions
diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S deleted file mode 100644 index 6dbcc95b2120..000000000000 --- a/arch/i386/boot/setup.S +++ /dev/null @@ -1,1075 +0,0 @@ -/* - * setup.S Copyright (C) 1991, 1992 Linus Torvalds - * - * setup.s is responsible for getting the system data from the BIOS, - * and putting them into the appropriate places in system memory. - * both setup.s and system has been loaded by the bootblock. - * - * This code asks the bios for memory/disk/other parameters, and - * puts them in a "safe" place: 0x90000-0x901FF, ie where the - * boot-block used to be. It is then up to the protected mode - * system to read them from there before the area is overwritten - * for buffer-blocks. - * - * Move PS/2 aux init code to psaux.c - * (troyer@saifr00.cfsat.Honeywell.COM) 03Oct92 - * - * some changes and additional features by Christoph Niemann, - * March 1993/June 1994 (Christoph.Niemann@linux.org) - * - * add APM BIOS checking by Stephen Rothwell, May 1994 - * (sfr@canb.auug.org.au) - * - * High load stuff, initrd support and position independency - * by Hans Lermen & Werner Almesberger, February 1996 - * <lermen@elserv.ffm.fgan.de>, <almesber@lrc.epfl.ch> - * - * Video handling moved to video.S by Martin Mares, March 1996 - * <mj@k332.feld.cvut.cz> - * - * Extended memory detection scheme retwiddled by orc@pell.chi.il.us (david - * parsons) to avoid loadlin confusion, July 1997 - * - * Transcribed from Intel (as86) -> AT&T (gas) by Chris Noe, May 1999. - * <stiker@northlink.com> - * - * Fix to work around buggy BIOSes which don't use carry bit correctly - * and/or report extended memory in CX/DX for e801h memory size detection - * call. As a result the kernel got wrong figures. The int15/e801h docs - * from Ralf Brown interrupt list seem to indicate AX/BX should be used - * anyway. So to avoid breaking many machines (presumably there was a reason - * to orginally use CX/DX instead of AX/BX), we do a kludge to see - * if CX/DX have been changed in the e801 call and if so use AX/BX . - * Michael Miller, April 2001 <michaelm@mjmm.org> - * - * New A20 code ported from SYSLINUX by H. Peter Anvin. AMD Elan bugfixes - * by Robert Schwebel, December 2001 <robert@schwebel.de> - */ - -#include <asm/segment.h> -#include <linux/utsrelease.h> -#include <linux/compile.h> -#include <asm/boot.h> -#include <asm/e820.h> -#include <asm/page.h> -#include <asm/setup.h> - -/* Signature words to ensure LILO loaded us right */ -#define SIG1 0xAA55 -#define SIG2 0x5A5A - -INITSEG = DEF_INITSEG # 0x9000, we move boot here, out of the way -SYSSEG = DEF_SYSSEG # 0x1000, system loaded at 0x10000 (65536). -SETUPSEG = DEF_SETUPSEG # 0x9020, this is the current segment - # ... and the former contents of CS - -DELTA_INITSEG = SETUPSEG - INITSEG # 0x0020 - -.code16 -.globl begtext, begdata, begbss, endtext, enddata, endbss - -.text -begtext: -.data -begdata: -.bss -begbss: -.text - -start: - jmp trampoline - -# This is the setup header, and it must start at %cs:2 (old 0x9020:2) - - .ascii "HdrS" # header signature - .word 0x0206 # header version number (>= 0x0105) - # or else old loadlin-1.5 will fail) -realmode_swtch: .word 0, 0 # default_switch, SETUPSEG -start_sys_seg: .word SYSSEG - .word kernel_version # pointing to kernel version string - # above section of header is compatible - # with loadlin-1.5 (header v1.5). Don't - # change it. - -type_of_loader: .byte 0 # = 0, old one (LILO, Loadlin, - # Bootlin, SYSLX, bootsect...) - # See Documentation/i386/boot.txt for - # assigned ids - -# flags, unused bits must be zero (RFU) bit within loadflags -loadflags: -LOADED_HIGH = 1 # If set, the kernel is loaded high -CAN_USE_HEAP = 0x80 # If set, the loader also has set - # heap_end_ptr to tell how much - # space behind setup.S can be used for - # heap purposes. - # Only the loader knows what is free -#ifndef __BIG_KERNEL__ - .byte 0 -#else - .byte LOADED_HIGH -#endif - -setup_move_size: .word 0x8000 # size to move, when setup is not - # loaded at 0x90000. We will move setup - # to 0x90000 then just before jumping - # into the kernel. However, only the - # loader knows how much data behind - # us also needs to be loaded. - -code32_start: # here loaders can put a different - # start address for 32-bit code. -#ifndef __BIG_KERNEL__ - .long 0x1000 # 0x1000 = default for zImage -#else - .long 0x100000 # 0x100000 = default for big kernel -#endif - -ramdisk_image: .long 0 # address of loaded ramdisk image - # Here the loader puts the 32-bit - # address where it loaded the image. - # This only will be read by the kernel. - -ramdisk_size: .long 0 # its size in bytes - -bootsect_kludge: - .long 0 # obsolete - -heap_end_ptr: .word modelist+1024 # (Header version 0x0201 or later) - # space from here (exclusive) down to - # end of setup code can be used by setup - # for local heap purposes. - -pad1: .word 0 -cmd_line_ptr: .long 0 # (Header version 0x0202 or later) - # If nonzero, a 32-bit pointer - # to the kernel command line. - # The command line should be - # located between the start of - # setup and the end of low - # memory (0xa0000), or it may - # get overwritten before it - # gets read. If this field is - # used, there is no longer - # anything magical about the - # 0x90000 segment; the setup - # can be located anywhere in - # low memory 0x10000 or higher. - -ramdisk_max: .long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff - # (Header version 0x0203 or later) - # The highest safe address for - # the contents of an initrd - -kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment - #required for protected mode - #kernel -#ifdef CONFIG_RELOCATABLE -relocatable_kernel: .byte 1 -#else -relocatable_kernel: .byte 0 -#endif -pad2: .byte 0 -pad3: .word 0 - -cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line, - #added with boot protocol - #version 2.06 - -trampoline: call start_of_setup - .align 16 - # The offset at this point is 0x240 - .space (0xeff-0x240+1) # E820 & EDD space (ending at 0xeff) -# End of setup header ##################################################### - -start_of_setup: -# Bootlin depends on this being done early - movw $0x01500, %ax - movb $0x81, %dl - int $0x13 - -#ifdef SAFE_RESET_DISK_CONTROLLER -# Reset the disk controller. - movw $0x0000, %ax - movb $0x80, %dl - int $0x13 -#endif - -# Set %ds = %cs, we know that SETUPSEG = %cs at this point - movw %cs, %ax # aka SETUPSEG - movw %ax, %ds -# Check signature at end of setup - cmpw $SIG1, setup_sig1 - jne bad_sig - - cmpw $SIG2, setup_sig2 - jne bad_sig - - jmp good_sig1 - -# Routine to print asciiz string at ds:si -prtstr: - lodsb - andb %al, %al - jz fin - - call prtchr - jmp prtstr - -fin: ret - -# Space printing -prtsp2: call prtspc # Print double space -prtspc: movb $0x20, %al # Print single space (note: fall-thru) - -# Part of above routine, this one just prints ascii al -prtchr: pushw %ax - pushw %cx - movw $7,%bx - movw $0x01, %cx - movb $0x0e, %ah - int $0x10 - popw %cx - popw %ax - ret - -beep: movb $0x07, %al - jmp prtchr - -no_sig_mess: .string "No setup signature found ..." - -good_sig1: - jmp good_sig - -# We now have to find the rest of the setup code/data -bad_sig: - movw %cs, %ax # SETUPSEG - subw $DELTA_INITSEG, %ax # INITSEG - movw %ax, %ds - xorb %bh, %bh - movb (497), %bl # get setup sect from bootsect - subw $4, %bx # LILO loads 4 sectors of setup - shlw $8, %bx # convert to words (1sect=2^8 words) - movw %bx, %cx - shrw $3, %bx # convert to segment - addw $SYSSEG, %bx - movw %bx, %cs:start_sys_seg -# Move rest of setup code/data to here - movw $2048, %di # four sectors loaded by LILO - subw %si, %si - pushw %cs - popw %es - movw $SYSSEG, %ax - movw %ax, %ds - rep - movsw - movw %cs, %ax # aka SETUPSEG - movw %ax, %ds - cmpw $SIG1, setup_sig1 - jne no_sig - - cmpw $SIG2, setup_sig2 - jne no_sig - - jmp good_sig - -no_sig: - lea no_sig_mess, %si - call prtstr - -no_sig_loop: - hlt - jmp no_sig_loop - -good_sig: - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ax, %ds -# Check if an old loader tries to load a big-kernel - testb $LOADED_HIGH, %cs:loadflags # Do we have a big kernel? - jz loader_ok # No, no danger for old loaders. - - cmpb $0, %cs:type_of_loader # Do we have a loader that - # can deal with us? - jnz loader_ok # Yes, continue. - - pushw %cs # No, we have an old loader, - popw %ds # die. - lea loader_panic_mess, %si - call prtstr - - jmp no_sig_loop - -loader_panic_mess: .string "Wrong loader, giving up..." - -# check minimum cpuid -# we do this here because it is the last place we can actually -# show a user visible error message. Later the video modus -# might be already messed up. -loader_ok: - call verify_cpu - testl %eax,%eax - jz cpu_ok - movw %cs,%ax # aka SETUPSEG - movw %ax,%ds - lea cpu_panic_mess,%si - call prtstr -1: jmp 1b - -cpu_panic_mess: - .asciz "PANIC: CPU too old for this kernel." - -#include "../kernel/verify_cpu.S" - -cpu_ok: -# Get memory size (extended mem, kB) - - xorl %eax, %eax - movl %eax, (0x1e0) -#ifndef STANDARD_MEMORY_BIOS_CALL - movb %al, (E820NR) -# Try three different memory detection schemes. First, try -# e820h, which lets us assemble a memory map, then try e801h, -# which returns a 32-bit memory size, and finally 88h, which -# returns 0-64m - -# method E820H: -# the memory map from hell. e820h returns memory classified into -# a whole bunch of different types, and allows memory holes and -# everything. We scan through this memory map and build a list -# of the first 32 memory areas, which we return at [E820MAP]. -# This is documented at http://www.acpi.info/, in the ACPI 2.0 specification. - -#define SMAP 0x534d4150 - -meme820: - xorl %ebx, %ebx # continuation counter - movw $E820MAP, %di # point into the whitelist - # so we can have the bios - # directly write into it. - -jmpe820: - movl $0x0000e820, %eax # e820, upper word zeroed - movl $SMAP, %edx # ascii 'SMAP' - movl $20, %ecx # size of the e820rec - pushw %ds # data record. - popw %es - int $0x15 # make the call - jc bail820 # fall to e801 if it fails - - cmpl $SMAP, %eax # check the return is `SMAP' - jne bail820 # fall to e801 if it fails - -# cmpl $1, 16(%di) # is this usable memory? -# jne again820 - - # If this is usable memory, we save it by simply advancing %di by - # sizeof(e820rec). - # -good820: - movb (E820NR), %al # up to 128 entries - cmpb $E820MAX, %al - jae bail820 - - incb (E820NR) - movw %di, %ax - addw $20, %ax - movw %ax, %di -again820: - cmpl $0, %ebx # check to see if - jne jmpe820 # %ebx is set to EOF -bail820: - - -# method E801H: -# memory size is in 1k chunksizes, to avoid confusing loadlin. -# we store the 0xe801 memory size in a completely different place, -# because it will most likely be longer than 16 bits. -# (use 1e0 because that's what Larry Augustine uses in his -# alternative new memory detection scheme, and it's sensible -# to write everything into the same place.) - -meme801: - stc # fix to work around buggy - xorw %cx,%cx # BIOSes which don't clear/set - xorw %dx,%dx # carry on pass/error of - # e801h memory size call - # or merely pass cx,dx though - # without changing them. - movw $0xe801, %ax - int $0x15 - jc mem88 - - cmpw $0x0, %cx # Kludge to handle BIOSes - jne e801usecxdx # which report their extended - cmpw $0x0, %dx # memory in AX/BX rather than - jne e801usecxdx # CX/DX. The spec I have read - movw %ax, %cx # seems to indicate AX/BX - movw %bx, %dx # are more reasonable anyway... - -e801usecxdx: - andl $0xffff, %edx # clear sign extend - shll $6, %edx # and go from 64k to 1k chunks - movl %edx, (0x1e0) # store extended memory size - andl $0xffff, %ecx # clear sign extend - addl %ecx, (0x1e0) # and add lower memory into - # total size. - -# Ye Olde Traditional Methode. Returns the memory size (up to 16mb or -# 64mb, depending on the bios) in ax. -mem88: - -#endif - movb $0x88, %ah - int $0x15 - movw %ax, (2) - -# Set the keyboard repeat rate to the max - movw $0x0305, %ax - xorw %bx, %bx - int $0x16 - -# Check for video adapter and its parameters and allow the -# user to browse video modes. - call video # NOTE: we need %ds pointing - # to bootsector - -# Get hd0 data... - xorw %ax, %ax - movw %ax, %ds - ldsw (4 * 0x41), %si - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - pushw %ax - movw %ax, %es - movw $0x0080, %di - movw $0x10, %cx - pushw %cx - cld - rep - movsb -# Get hd1 data... - xorw %ax, %ax - movw %ax, %ds - ldsw (4 * 0x46), %si - popw %cx - popw %es - movw $0x0090, %di - rep - movsb -# Check that there IS a hd1 :-) - movw $0x01500, %ax - movb $0x81, %dl - int $0x13 - jc no_disk1 - - cmpb $3, %ah - je is_disk1 - -no_disk1: - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ax, %es - movw $0x0090, %di - movw $0x10, %cx - xorw %ax, %ax - cld - rep - stosb -is_disk1: -# check for Micro Channel (MCA) bus - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ax, %ds - xorw %ax, %ax - movw %ax, (0xa0) # set table length to 0 - movb $0xc0, %ah - stc - int $0x15 # moves feature table to es:bx - jc no_mca - - pushw %ds - movw %es, %ax - movw %ax, %ds - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ax, %es - movw %bx, %si - movw $0xa0, %di - movw (%si), %cx - addw $2, %cx # table length is a short - cmpw $0x10, %cx - jc sysdesc_ok - - movw $0x10, %cx # we keep only first 16 bytes -sysdesc_ok: - rep - movsb - popw %ds -no_mca: -#ifdef CONFIG_X86_VOYAGER - movb $0xff, 0x40 # flag on config found - movb $0xc0, %al - mov $0xff, %ah - int $0x15 # put voyager config info at es:di - jc no_voyager - movw $0x40, %si # place voyager info in apm table - cld - movw $7, %cx -voyager_rep: - movb %es:(%di), %al - movb %al,(%si) - incw %di - incw %si - decw %cx - jnz voyager_rep -no_voyager: -#endif -# Check for PS/2 pointing device - movw %cs, %ax # aka SETUPSEG - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ax, %ds - movb $0, (0x1ff) # default is no pointing device - int $0x11 # int 0x11: equipment list - testb $0x04, %al # check if mouse installed - jz no_psmouse - - movb $0xAA, (0x1ff) # device present -no_psmouse: - -#if defined(CONFIG_X86_SPEEDSTEP_SMI) || defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE) - movl $0x0000E980, %eax # IST Support - movl $0x47534943, %edx # Request value - int $0x15 - - movl %eax, (96) - movl %ebx, (100) - movl %ecx, (104) - movl %edx, (108) -#endif - -#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE) -# Then check for an APM BIOS... - # %ds points to the bootsector - movw $0, 0x40 # version = 0 means no APM BIOS - movw $0x05300, %ax # APM BIOS installation check - xorw %bx, %bx - int $0x15 - jc done_apm_bios # Nope, no APM BIOS - - cmpw $0x0504d, %bx # Check for "PM" signature - jne done_apm_bios # No signature, no APM BIOS - - andw $0x02, %cx # Is 32 bit supported? - je done_apm_bios # No 32-bit, no (good) APM BIOS - - movw $0x05304, %ax # Disconnect first just in case - xorw %bx, %bx - int $0x15 # ignore return code - movw $0x05303, %ax # 32 bit connect - xorl %ebx, %ebx - xorw %cx, %cx # paranoia :-) - xorw %dx, %dx # ... - xorl %esi, %esi # ... - xorw %di, %di # ... - int $0x15 - jc no_32_apm_bios # Ack, error. - - movw %ax, (66) # BIOS code segment - movl %ebx, (68) # BIOS entry point offset - movw %cx, (72) # BIOS 16 bit code segment - movw %dx, (74) # BIOS data segment - movl %esi, (78) # BIOS code segment lengths - movw %di, (82) # BIOS data segment length -# Redo the installation check as the 32 bit connect -# modifies the flags returned on some BIOSs - movw $0x05300, %ax # APM BIOS installation check - xorw %bx, %bx - xorw %cx, %cx # paranoia - int $0x15 - jc apm_disconnect # error -> shouldn't happen - - cmpw $0x0504d, %bx # check for "PM" signature - jne apm_disconnect # no sig -> shouldn't happen - - movw %ax, (64) # record the APM BIOS version - movw %cx, (76) # and flags - jmp done_apm_bios - -apm_disconnect: # Tidy up - movw $0x05304, %ax # Disconnect - xorw %bx, %bx - int $0x15 # ignore return code - - jmp done_apm_bios - -no_32_apm_bios: - andw $0xfffd, (76) # remove 32 bit support bit -done_apm_bios: -#endif - -#include "edd.S" - -# Now we want to move to protected mode ... - cmpw $0, %cs:realmode_swtch - jz rmodeswtch_normal - - lcall *%cs:realmode_swtch - - jmp rmodeswtch_end - -rmodeswtch_normal: - pushw %cs - call default_switch - -rmodeswtch_end: -# Now we move the system to its rightful place ... but we check if we have a -# big-kernel. In that case we *must* not move it ... - testb $LOADED_HIGH, %cs:loadflags - jz do_move0 # .. then we have a normal low - # loaded zImage - # .. or else we have a high - # loaded bzImage - jmp end_move # ... and we skip moving - -do_move0: - movw $0x100, %ax # start of destination segment - movw %cs, %bp # aka SETUPSEG - subw $DELTA_INITSEG, %bp # aka INITSEG - movw %cs:start_sys_seg, %bx # start of source segment - cld -do_move: - movw %ax, %es # destination segment - incb %ah # instead of add ax,#0x100 - movw %bx, %ds # source segment - addw $0x100, %bx - subw %di, %di - subw %si, %si - movw $0x800, %cx - rep - movsw - cmpw %bp, %bx # assume start_sys_seg > 0x200, - # so we will perhaps read one - # page more than needed, but - # never overwrite INITSEG - # because destination is a - # minimum one page below source - jb do_move - -end_move: -# then we load the segment descriptors - movw %cs, %ax # aka SETUPSEG - movw %ax, %ds - -# Check whether we need to be downward compatible with version <=201 - cmpl $0, cmd_line_ptr - jne end_move_self # loader uses version >=202 features - cmpb $0x20, type_of_loader - je end_move_self # bootsect loader, we know of it - -# Boot loader doesnt support boot protocol version 2.02. -# If we have our code not at 0x90000, we need to move it there now. -# We also then need to move the params behind it (commandline) -# Because we would overwrite the code on the current IP, we move -# it in two steps, jumping high after the first one. - movw %cs, %ax - cmpw $SETUPSEG, %ax - je end_move_self - - cli # make sure we really have - # interrupts disabled ! - # because after this the stack - # should not be used - subw $DELTA_INITSEG, %ax # aka INITSEG - movw %ss, %dx - cmpw %ax, %dx - jb move_self_1 - - addw $INITSEG, %dx - subw %ax, %dx # this will go into %ss after - # the move -move_self_1: - movw %ax, %ds - movw $INITSEG, %ax # real INITSEG - movw %ax, %es - movw %cs:setup_move_size, %cx - std # we have to move up, so we use - # direction down because the - # areas may overlap - movw %cx, %di - decw %di - movw %di, %si - subw $move_self_here+0x200, %cx - rep - movsb - ljmp $SETUPSEG, $move_self_here - -move_self_here: - movw $move_self_here+0x200, %cx - rep - movsb - movw $SETUPSEG, %ax - movw %ax, %ds - movw %dx, %ss -end_move_self: # now we are at the right place - -# -# Enable A20. This is at the very best an annoying procedure. -# A20 code ported from SYSLINUX 1.52-1.63 by H. Peter Anvin. -# AMD Elan bug fix by Robert Schwebel. -# - -#if defined(CONFIG_X86_ELAN) - movb $0x02, %al # alternate A20 gate - outb %al, $0x92 # this works on SC410/SC520 -a20_elan_wait: - call a20_test - jz a20_elan_wait - jmp a20_done -#endif - - -A20_TEST_LOOPS = 32 # Iterations per wait -A20_ENABLE_LOOPS = 255 # Total loops to try - - -#ifndef CONFIG_X86_VOYAGER -a20_try_loop: - - # First, see if we are on a system with no A20 gate. -a20_none: - call a20_test - jnz a20_done - - # Next, try the BIOS (INT 0x15, AX=0x2401) -a20_bios: - movw $0x2401, %ax - pushfl # Be paranoid about flags - int $0x15 - popfl - - call a20_test - jnz a20_done - - # Try enabling A20 through the keyboard controller -#endif /* CONFIG_X86_VOYAGER */ -a20_kbc: - call empty_8042 - -#ifndef CONFIG_X86_VOYAGER - call a20_test # Just in case the BIOS worked - jnz a20_done # but had a delayed reaction. -#endif - - movb $0xD1, %al # command write - outb %al, $0x64 - call empty_8042 - - movb $0xDF, %al # A20 on - outb %al, $0x60 - call empty_8042 - -#ifndef CONFIG_X86_VOYAGER - # Wait until a20 really *is* enabled; it can take a fair amount of - # time on certain systems; Toshiba Tecras are known to have this - # problem. -a20_kbc_wait: - xorw %cx, %cx -a20_kbc_wait_loop: - call a20_test - jnz a20_done - loop a20_kbc_wait_loop - - # Final attempt: use "configuration port A" -a20_fast: - inb $0x92, %al # Configuration Port A - orb $0x02, %al # "fast A20" version - andb $0xFE, %al # don't accidentally reset - outb %al, $0x92 - - # Wait for configuration port A to take effect -a20_fast_wait: - xorw %cx, %cx -a20_fast_wait_loop: - call a20_test - jnz a20_done - loop a20_fast_wait_loop - - # A20 is still not responding. Try frobbing it again. - # - decb (a20_tries) - jnz a20_try_loop - - movw $a20_err_msg, %si - call prtstr - -a20_die: - hlt - jmp a20_die - -a20_tries: - .byte A20_ENABLE_LOOPS - -a20_err_msg: - .ascii "linux: fatal error: A20 gate not responding!" - .byte 13, 10, 0 - - # If we get here, all is good -a20_done: - -#endif /* CONFIG_X86_VOYAGER */ -# set up gdt and idt and 32bit start address - lidt idt_48 # load idt with 0,0 - xorl %eax, %eax # Compute gdt_base - movw %ds, %ax # (Convert %ds:gdt to a linear ptr) - shll $4, %eax - addl %eax, code32 - addl $gdt, %eax - movl %eax, (gdt_48+2) - lgdt gdt_48 # load gdt with whatever is - # appropriate - -# make sure any possible coprocessor is properly reset.. - xorw %ax, %ax - outb %al, $0xf0 - call delay - - outb %al, $0xf1 - call delay - -# well, that went ok, I hope. Now we mask all interrupts - the rest -# is done in init_IRQ(). - movb $0xFF, %al # mask all interrupts for now - outb %al, $0xA1 - call delay - - movb $0xFB, %al # mask all irq's but irq2 which - outb %al, $0x21 # is cascaded - -# Well, that certainly wasn't fun :-(. Hopefully it works, and we don't -# need no steenking BIOS anyway (except for the initial loading :-). -# The BIOS-routine wants lots of unnecessary data, and it's less -# "interesting" anyway. This is how REAL programmers do it. -# -# Well, now's the time to actually move into protected mode. To make -# things as simple as possible, we do no register set-up or anything, -# we let the gnu-compiled 32-bit programs do that. We just jump to -# absolute address 0x1000 (or the loader supplied one), -# in 32-bit protected mode. -# -# Note that the short jump isn't strictly needed, although there are -# reasons why it might be a good idea. It won't hurt in any case. - movw $1, %ax # protected mode (PE) bit - lmsw %ax # This is it! - jmp flush_instr - -flush_instr: - xorw %bx, %bx # Flag to indicate a boot - xorl %esi, %esi # Pointer to real-mode code - movw %cs, %si - subw $DELTA_INITSEG, %si - shll $4, %esi # Convert to 32-bit pointer - -# jump to startup_32 in arch/i386/boot/compressed/head.S -# -# NOTE: For high loaded big kernels we need a -# jmpi 0x100000,__BOOT_CS -# -# but we yet haven't reloaded the CS register, so the default size -# of the target offset still is 16 bit. -# However, using an operand prefix (0x66), the CPU will properly -# take our 48 bit far pointer. (INTeL 80386 Programmer's Reference -# Manual, Mixing 16-bit and 32-bit code, page 16-6) - - .byte 0x66, 0xea # prefix + jmpi-opcode -code32: .long startup_32 # will be set to %cs+startup_32 - .word __BOOT_CS -.code32 -startup_32: - movl $(__BOOT_DS), %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %fs - movl %eax, %gs - movl %eax, %ss - - xorl %eax, %eax -1: incl %eax # check that A20 really IS enabled - movl %eax, 0x00000000 # loop forever if it isn't - cmpl %eax, 0x00100000 - je 1b - - # Jump to the 32bit entry point - jmpl *(code32_start - start + (DELTA_INITSEG << 4))(%esi) -.code16 - -# Here's a bunch of information about your current kernel.. -kernel_version: .ascii UTS_RELEASE - .ascii " (" - .ascii LINUX_COMPILE_BY - .ascii "@" - .ascii LINUX_COMPILE_HOST - .ascii ") " - .ascii UTS_VERSION - .byte 0 - -# This is the default real mode switch routine. -# to be called just before protected mode transition -default_switch: - cli # no interrupts allowed ! - movb $0x80, %al # disable NMI for bootup - # sequence - outb %al, $0x70 - lret - - -#ifndef CONFIG_X86_VOYAGER -# This routine tests whether or not A20 is enabled. If so, it -# exits with zf = 0. -# -# The memory address used, 0x200, is the int $0x80 vector, which -# should be safe. - -A20_TEST_ADDR = 4*0x80 - -a20_test: - pushw %cx - pushw %ax - xorw %cx, %cx - movw %cx, %fs # Low memory - decw %cx - movw %cx, %gs # High memory area - movw $A20_TEST_LOOPS, %cx - movw %fs:(A20_TEST_ADDR), %ax - pushw %ax -a20_test_wait: - incw %ax - movw %ax, %fs:(A20_TEST_ADDR) - call delay # Serialize and make delay constant - cmpw %gs:(A20_TEST_ADDR+0x10), %ax - loope a20_test_wait - - popw %fs:(A20_TEST_ADDR) - popw %ax - popw %cx - ret - -#endif /* CONFIG_X86_VOYAGER */ - -# This routine checks that the keyboard command queue is empty -# (after emptying the output buffers) -# -# Some machines have delusions that the keyboard buffer is always full -# with no keyboard attached... -# -# If there is no keyboard controller, we will usually get 0xff -# to all the reads. With each IO taking a microsecond and -# a timeout of 100,000 iterations, this can take about half a -# second ("delay" == outb to port 0x80). That should be ok, -# and should also be plenty of time for a real keyboard controller -# to empty. -# - -empty_8042: - pushl %ecx - movl $100000, %ecx - -empty_8042_loop: - decl %ecx - jz empty_8042_end_loop - - call delay - - inb $0x64, %al # 8042 status port - testb $1, %al # output buffer? - jz no_output - - call delay - inb $0x60, %al # read it - jmp empty_8042_loop - -no_output: - testb $2, %al # is input buffer full? - jnz empty_8042_loop # yes - loop -empty_8042_end_loop: - popl %ecx - ret - -# Read the cmos clock. Return the seconds in al -gettime: - pushw %cx - movb $0x02, %ah - int $0x1a - movb %dh, %al # %dh contains the seconds - andb $0x0f, %al - movb %dh, %ah - movb $0x04, %cl - shrb %cl, %ah - aad - popw %cx - ret - -# Delay is needed after doing I/O -delay: - outb %al,$0x80 - ret - -# Descriptor tables -# -# NOTE: The intel manual says gdt should be sixteen bytes aligned for -# efficiency reasons. However, there are machines which are known not -# to boot with misaligned GDTs, so alter this at your peril! If you alter -# GDT_ENTRY_BOOT_CS (in asm/segment.h) remember to leave at least two -# empty GDT entries (one for NULL and one reserved). -# -# NOTE: On some CPUs, the GDT must be 8 byte aligned. This is -# true for the Voyager Quad CPU card which will not boot without -# This directive. 16 byte aligment is recommended by intel. -# - .align 16 -gdt: - .fill GDT_ENTRY_BOOT_CS,8,0 - - .word 0xFFFF # 4Gb - (0x100000*0x1000 = 4Gb) - .word 0 # base address = 0 - .word 0x9A00 # code read/exec - .word 0x00CF # granularity = 4096, 386 - # (+5th nibble of limit) - - .word 0xFFFF # 4Gb - (0x100000*0x1000 = 4Gb) - .word 0 # base address = 0 - .word 0x9200 # data read/write - .word 0x00CF # granularity = 4096, 386 - # (+5th nibble of limit) -gdt_end: - .align 4 - - .word 0 # alignment byte -idt_48: - .word 0 # idt limit = 0 - .word 0, 0 # idt base = 0L - - .word 0 # alignment byte -gdt_48: - .word gdt_end - gdt - 1 # gdt limit - .word 0, 0 # gdt base (filled in later) - -# Include video setup & detection code - -#include "video.S" - -# Setup signature -- must be last -setup_sig1: .word SIG1 -setup_sig2: .word SIG2 - -# After this point, there is some free space which is used by the video mode -# handling code to store the temporary mode table (not used by the kernel). - -modelist: - -.text -endtext: -.data -enddata: -.bss -endbss: |