1 /* machdep.c 1.5 90/12/16 */ 2 3 #include "../tahoe/mem.h" 4 #include "../include/mtpr.h" 5 #include "../tahoe/SYS.h" 6 7 .set _scb, 0x0 8 .set HIGH, 0x1f # mask for total disable 9 .set BERVEC, 0x80 # offset into scb of the bus error vector 10 .set RESTVEC, 0x8 # offset into scb of the restart vector 11 12 ENTRY(mtpr, 0) 13 mtpr 8(fp),4(fp) 14 ret 15 16 ENTRY(mfpr, 0) 17 mfpr 4(fp),r0 18 ret 19 20 ENTRY(bcopy, R2|R1|R0) 21 movl 4(fp),r0 22 movl 8(fp),r1 23 movl 12(fp),r2 24 movblk 25 ret 26 27 /* 28 * badaddr(addr, len) 29 * see if access addr with a len type instruction causes a machine check 30 * len is length of access (1=byte, 2=short, 4=long) 31 * r0 = 0 means good(exists); r0 =1 means does not exist. 32 */ 33 ENTRY(badaddr, R5|R4|R3|R2|R1) 34 mfpr $IPL,r1 35 mtpr $HIGH,$IPL 36 mfpr $SCBB,r5 37 mtpr $0,$SCBB 38 movl *$BERVEC,r2 39 movl 4(fp),r3 40 movl 8(fp),r4 41 movab 9f,*$BERVEC 42 bbc $0,r4,1f; tstb (r3) 43 1: bbc $1,r4,1f; tstw (r3) 44 1: bbc $2,r4,1f; tstl (r3) 45 1: clrl r0 # made it w/o machine checks 46 2: movl r2,*$BERVEC 47 mtpr r1,$IPL 48 mtpr r5,$SCBB 49 ret 50 51 /* 52 * wbadaddr(addr, len, value) 53 * see if write of value to addr with a len type instruction causes 54 * a machine check 55 * len is length of access (1=byte, 2=short, 4=long) 56 * r0 = 0 means good(exists); r0 =1 means does not exist. 57 */ 58 ENTRY(wbadaddr, R5|R4|R3|R2|R1) 59 mfpr $IPL,r1 60 mtpr $HIGH,$IPL 61 mfpr $SCBB,r5 62 mtpr $0,$SCBB 63 movl *$BERVEC,r2 64 movl 4(fp),r3 65 movl 8(fp),r4 66 movab 9f,*$BERVEC 67 bbc $0,r4,1f; movb 15(fp), (r3) 68 1: bbc $1,r4,1f; movw 14(fp), (r3) 69 1: bbc $2,r4,1f; movl 12(fp), (r3) 70 1: clrl r0 # made it w/o machine checks 71 2: movl r2,*$BERVEC 72 mtpr r1,$IPL 73 mtpr r5,$SCBB 74 ret 75 76 .align 2 77 9: # Here we catch buss error (if it comes) 78 andl3 4(sp),$ERRCD,r0 79 cmpl r0,$APE 80 jneq 1f 81 halt # Address parity error !!! 82 1: cmpl r0,$VBE 83 jneq 1f 84 halt # Versabus error 85 1: 86 movl $1,r0 # Anything else = bad address 87 movab 8(sp),sp # discard buss error trash 88 movab 2b,(sp) # new program counter on stack. 89 rei 90 91 ENTRY(movow, 0) 92 movow 10(fp),*4(fp) 93 ret 94 95 ENTRY(movob, 0) 96 movob 11(fp),*4(fp) 97 ret 98