1 /* raboot.c 6.1 83/07/29 */ 2 3 /* 4 * UDA50 1st level boot program: loads next 7.5Kbytes from 5 * boot sector of file system and sets it up to run. 6 */ 7 .set RELOC,0x50000 8 .set BOOTLAST,15 /* last boot sector */ 9 .set RABPSECT,512 /* bytes per sector */ 10 11 init: 12 .word 0 /* entry mask for dec monitor */ 13 nop;nop;nop;nop;nop;nop;nop;nop /* some no-ops for 750 boot to skip */ 14 nop;nop; 15 start: 16 movl r1,r7 /* UNIBUS I/O page address */ 17 movl r2,r8 /* boot device CSR */ 18 movl r3,r9 /* unit number */ 19 movl r5,r11 /* boot flags */ 20 movl $RELOC,sp 21 moval init,r10 22 movc3 $end,(r10),(sp) 23 movl r7,r1 /* UNIBUS I/O page address */ 24 movl r8,r2 /* boot device CSR */ 25 movl r9,r3 /* unit number */ 26 jmp *$RELOC+start2 27 /* now running relocated */ 28 /* bring in the boot program */ 29 start2: /* running relocated */ 30 pushr $0xffff /* BEGIN FIREWALL */ 31 movl $1,r4 /* first boot sector */ 32 clrl r5 /* transfer address */ 33 clrl -(sp) /* transfer address */ 34 1: 35 movl r4,r8 /* requested sector # */ 36 jsb (r6) /* call ROM-based driver */ 37 blbs r0,2f 38 halt /* read error */ 39 2: 40 addl2 $RABPSECT,r5 /* bump address */ 41 movl r5,(sp) 42 aobleq $BOOTLAST,r4,1b 43 44 .set PROGSIZE,((BOOTLAST-1)*RABPSECT) 45 done: 46 tstl (sp)+ /* pop address */ 47 popr $0xffff /* END FIREWALL */ 48 movl $PROGSIZE,r3 49 clrcor: 50 clrq (r3) 51 acbl $RELOC,$8,r3,clrcor 52 /* start loaded program */ 53 movl $9,r10 /* major("/dev/ra0a") */ 54 calls $0,*$0 55 brw start2 56 end: 57