Deleted the private cleandir target. It didn't had a rule for the

[unix-history] / sys / i386 / boot / boot2.S

/*
* Mach Operating System
* Copyright (c) 1992, 1991 Carnegie Mellon University
* All Rights Reserved.
* 
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
* 
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
* 
* Carnegie Mellon requests users of this software to return to
* 
*  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
*  School of Computer Science
*  Carnegie Mellon University
*  Pittsburgh PA 15213-3890
* 
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*
*      from: Mach, Revision 2.2  92/04/04  11:35:26  rpd
*      $Id: boot2.S,v 1.2 1993/10/16 19:11:33 rgrimes Exp $
*/

#include        "asm.h"

/* Conventional GDT indexes. */
#define BOOT_CS_INDEX           3
#define BOOT_CS16_INDEX         5
#define BOOT_DS_INDEX           4
#define DB_CS_INDEX             14
#define DB_CS16_INDEX           15
#define DB_DS_INDEX             16
#define GDT_INDEX               17

/* Vector numbers. */
#define BREAKPOINT_VECTOR       3
#define DEBUG_VECTOR            1

/*
* boot2() -- second stage boot
*/

.globl EXT(ouraddr)

ENTRY(boot2)
       data32
       subl    %eax, %eax
       mov     %cs, %ax
       mov     %ax, %ds
       mov     %ax, %es
       data32
       shll    $4, %eax
       addr32
       data32
       movl    %eax, EXT(ouraddr)

       /* fix up GDT entries for bootstrap */
#define FIXUP(gdt_index) \
       addr32; \
       movl    %eax, EXT(Gdt)+(8*gdt_index)+2; /* actually movw %ax */ \
       addr32; \
       movb    %bl, EXT(Gdt)+(8*gdt_index)+4

       data32
       shld    $16, %eax, %ebx
       FIXUP(BOOT_CS_INDEX)
       FIXUP(BOOT_CS16_INDEX)
       FIXUP(BOOT_DS_INDEX)

       /* fix up GDT entry for GDT, and GDT and IDT pointers */
       data32
       movl    %eax, %ecx
       data32
       addl    $ EXT(Gdt), %eax
       data32
       shld    $16, %eax, %ebx
       FIXUP(GDT_INDEX)
       addr32
       data32
       movl    %eax, EXT(Gdtr)+2
       data32
       addl    $ EXT(Idt), %ecx
       addr32
       data32
       movl    %ecx, EXT(Idtr_prot)+2

       /* %es = vector table segment for a while */
       push    %es
       data32
       subl    %eax, %eax
       mov     %ax, %es

       /* fix up GDT entries for bdb */
       data32
       movl    $4*DEBUG_VECTOR, %esi
       addr32
       movl    %es: 2(%esi), %eax      /* actually movw to %ax */
       data32
       shll    $4, %eax
       data32
       shld    $16, %eax, %ebx
       FIXUP(DB_CS_INDEX)
       FIXUP(DB_CS16_INDEX)
       FIXUP(DB_DS_INDEX)

       /* Fetch entry points of bdb's protected mode trap handlers.  These
        * are stored at 2 before the corresponding entry points for real mode.
        */
       data32
       subl    %ebx, %ebx
       addr32
       movl    %es: (%esi), %ebx       /* actually movw to %bx */
       data32
       subl    %ecx, %ecx
       addr32
       movl    %es: 4*(BREAKPOINT_VECTOR-DEBUG_VECTOR)(%esi), %ecx
                                       /* actually movw to %cx */

       /* %es = bdb segment for a while */
       data32
       shrl    $4, %eax
       mov     %ax, %es

       /* fix up IDT entries for bdb */
       subl    $2, %ebx
       movl    %es: (%ebx), %eax       /* actually movw to %ax */
       addr32
       movl    %eax, EXT(Idt)+8*DEBUG_VECTOR   /* actually movw %ax */
       subl    $2, %ecx
       movl    %es: (%ecx), %eax       /* actually movw to %ax */
       addr32
       movl    %eax, EXT(Idt)+8*BREAKPOINT_VECTOR      /* actually movw %ax */

       /* finished with groping in real mode segments */
       pop     %es

       /* change to protected mode */
       data32
       call    EXT(real_to_prot)

       /* clear the bss */
       movl    $ EXT(edata), %edi      /* no EXT(_edata) - krufty ld */
       movl    $ EXT(end), %ecx        /* or EXT(_end) */
       subl    %edi, %ecx
       subb    %al, %al
       rep
       stosb

       movzbl  %dl, %edx       /* discard head (%dh) and random high bits */
       pushl   %edx
       call    EXT(boot)
oops:
       hlt
       jmp     oops

       .data
       .align 2
#if 0 /* XXX this would give losing "_ouraddr :".  Better declared in C */
EXT(ouraddr):
#else
_ouraddr:
#endif
       .long 0