usr/src/sys/vax/mdec/hpboot.c

/*
 * Copyright (c) 1980,1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

/* "@(#)hpboot.c        7.2 (Berkeley) %G%" */
#include <sys/disklabel.h>


/*
 * RP??/RM?? 1st level boot program: loads next 7.5Kbytes from
 * boot sectors of file system and sets it up to run.
 * Reads from the controller and drive passed in from the boot
 * rom.
 *   R1:  address of the boot device's adapter
 *   R2:  controller number of the boot device
 *   R3:  unit number of the boot device
 *   R5:  software boot control flags
 *   R6:  address of driver subroutine from ROM
 *   SP:  base address of usable memory + 0x200
 */
        .set    BOOTSIZE,15             /* size of boot in sectors */
        .set    RELOC,0x70000
/* MBA registers */
        .set    M_cr,4                  /* MBA control reg */
        .set    M_sr,8                  /* MBA status reg */
        .set    M_var,12                /* MBA virt addr reg */
        .set    M_bc,16                 /* MBA byte count reg */
        .set    M_map,0x800             /* start of MBA map reg's */
        .set    MBAinit,1               /* MBA init bit in MBA control reg */
        .set    MBABUSY,0x80000000      /* MBA SR: data transfer busy */
        .set    pMBABUSY,31             /* bit position of  MBABUSY */
/* Drive information */
        .set    RP,0x400                /* start of drive registers */
        .set    RPDR,0x80               /* offset per drive unit */
        .set    RP_cr,0                 /* control status register */
        .set    RP_sr,4                 /* drive status reg */
        .set    RP_stk,0x14             /* desired track/sector reg */
        .set    RP_dt,0x18              /* drive type reg */
        .set    RP_off,0x24             /* RP offset reg */
        .set    RP_cyl,0x28             /* desired cyl reg */
        .set    RPBPSECT,512            /* bytes per sector */
/* RP?? function codes, status bits  */
        .set    RP_GO,1                 /* go */
        .set    RP_RED,070              /* read */
        .set    RP_DC,010               /* drive clear */
        .set    RP_RIP,020              /* read in preset */
        .set    RP_FMT,0x1000           /* format 22 */
        .set    RP_MOL,0x1000           /* medium on line */
        .set    RP_DRY,0200             /* drive ready */
        .set    RP_ERR,040000           /* composite error */
        .set    RP_pDRY,7               /* bit position of RP_DRY */
        .set    RP_pERR,14              /* bit position of RP_ERR */

init:
        .word   0                       /* entry mask for DEC monitor */
        nop;nop;nop;nop;nop;nop;nop;nop /* some no-ops for 750 boot to skip */
        nop;nop;
start:
        clrl    r10                     /* major("/dev/hp0a") */
        extzv   $13,$2,r1,r4            /* get MBA number from R1 */
        insv    r4,$24,$8,r10           /* set MBA number */
        insv    r3,$16,$8,r10           /* drive number */
        extzv   $12,$4,r5,r4            /* get partition from r5 */
        bicw2   $0xf000,r5              /* remove from r5 */
        insv    r4,$8,$4,r10            /* set partition */
        movl    r5,r11
        movl    r1,r9                   /* save adaptor address */
        movl    r3,r8                   /* and unit number */
        brw     start0

/*
 * Leave space for pack label.
 */
pad:
        .space  LABELOFFSET - (pad - init)
packlabel:
        .space  d_end_

start0:
        movl    $RELOC,sp
        moval   init,r6
        movc3   $end,(r6),(sp)
        jmp     *$RELOC+start1
/* running relocated */
start1:
        movl    $MBAinit,M_cr(r9)
/* read-in-preset the drive and set format */
        mull2   $RPDR,r8
        movab   RP(r9)[r8],r8
        movl    $RP_RIP+RP_GO,RP_cr(r8)
        movl    $RP_FMT,RP_off(r8)

        .set    PROGSIZE,(BOOTSIZE*RPBPSECT)
start2:
        movl    $0,RP_cyl(r8)
        movl    $1,RP_stk(r8)
        movl    $-PROGSIZE,M_bc(r9)
/* set up MASSBUS map for DMA */
        clrl    r0
1:
        bisl3   $0x80000000,r0,M_map(r9)[r0]
        aobleq  $BOOTSIZE,r0,1b
        clrl    M_var(r9)
        movl    $RP_RED+RP_GO,RP_cr(r8)
rprdy:
        movl    RP_sr(r8),r0
        bbc     $RP_pDRY,r0,rprdy
        bbs     $RP_pERR,r0,rperr
rprdy2:
        bbs     $pMBABUSY,M_sr(r9),rprdy2

/* Eagles are too fast for the controller. Slow the thing down. */
/* (May not be needed with wait for mba above.) */
        clrl    r3
buzz:   acbl    $2000,$1,r3,buzz
        bicpsw  $2
        jbr     clear
rperr:
        halt
/* clear core and execute program */
clear:
        movl    $PROGSIZE,r3
clrcor:
        clrq    (r3)
        acbl    $RELOC,$8,r3,clrcor
/* run loaded program */
        calls   $0,*$0
        brw     start2

end: