usr/src/sys/mdec/upboot.s

/*
 * 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.
 */

/* "@(#)upboot.s        7.1 (Berkeley) 6/5/86" */

        .set    MAJOR,2                 /* major("/dev/up0a") */

/*
 * UP 1st level boot program: loads next 7.5Kbytes from
 * boot sector of file system and sets it up to run.
 * Always reads from drive 0.
 */
        .set    BOOTSIZE,15             /* size of boot in sectors */
        .set    RELOC,0x50000
        .set    UPBPSECT,512            /* bytes per sector */
/* UBA registers */
        .set    UBA_CNFGR,0             /* UBA configuration register */
        .set    UBA_CR,4                /* UBA control register offset */
        .set    UBA_MAP,0x800           /* UBA offset to map reg's */
/* UP registers and bits */
        .set    UP_cs1,0                /* control and status */
        .set    UP_wc,2                 /* word count */
        .set    UP_ba,4                 /* bus address */
        .set    UP_da,6                 /* disk address */
        .set    UP_cs2,010              /* cs2 register */
        .set    UP_of,032               /* offset register */
        .set    UP_dc,034               /* desired cylinder */
        .set    UP_hr,036               /* holding register */
        .set    UP_GO,1                 /* go bit */
        .set    UP_PACK,022             /* pack acknowledge */
        .set    UP_DCLR,010             /* drive clear */
        .set    UP_PRESET,020           /* read-in-preset */
        .set    UP_RCOM,070             /* read command */
        .set    UPCS2_CLR,040
        .set    UP_pRDY,7               /* position of ready bit */
        .set    UP_pERR,15              /* position of error bit */
        .set    UP_FMT22,010000

init:
/* r9   UBA address */
/* r8   UP addr */
        .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;
        movl    $MAJOR,r10              /* major("/dev/xx0a") */
        extzv   $18,$1,r1,r9            /* get UBA number from R1 */
        xorb2   $0x01,r9                /* complement bit */
        insv    r9,$24,$8,r10           /* set UBA 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,$8,r10            /* set partition */
        movl    r5,r11                  /* boot flags */
        movl    physUBA[r9],r9          /* UNIBUS adaptor address */
        movl    r2,r8                   /* boot device CSR */
        movl    r3,r7                   /* unit number */

        movl    $RELOC,sp
        moval   init,r4
        movc3   $end,(r4),(sp)
        movl    r9,r1                   /* UNIBUS I/O page address */
        movl    r8,r2                   /* boot device CSR */
        movl    r7,r3                   /* unit number */
/* init up, set vv in drive; if any errors, give up */
        bisw3   r7,$UPCS2_CLR,UP_cs2(r8)
        movw    $UP_DCLR+UP_GO,UP_cs1(r8)
        movw    $UP_PRESET+UP_GO,UP_cs1(r8)
        movw    $UP_FMT22,UP_of(r8)
1:
        movw    UP_cs1(r8),r0
        bbc     $UP_pRDY,r0,1b
/* relocate to high core */
start:
        movl    r5,r11                  /* boot flags */
        movl    $RELOC,sp
        moval   init,r6
        movc3   $end,(r6),(sp)
        jmp     *$RELOC+start2
/* now running relocated */
        .set    PROGSIZE,(BOOTSIZE*UPBPSECT)
start2:
        movw    $0,UP_dc(r8)
        movw    $1,UP_da(r8)
        movw    $-PROGSIZE/2,UP_wc(r8)
        clrl    r0
1:
        bisl3   $0x80000000,r0,UBA_MAP(r9)
        addl2   $4,r9
        aobleq  $BOOTSIZE,r0,1b
        clrw    UP_ba(r8)
        movw    $UP_RCOM+UP_GO,UP_cs1(r8)
uprdy:
        movw    UP_cs1(r8),r0
        bbc     $UP_pRDY,r0,uprdy
clear:
        movl    $PROGSIZE,r3
clrcor:
        clrq    (r3)
        acbl    $RELOC,$8,r3,clrcor
/* run loaded program */
        calls   $0,*$0
        brw     start2
physUBA:
        .long   0xf30000                /* uba0 */
        .long   0xf32000                /* uba1 */
end: