2.11BSD#431 - /usr/src/sys/pdp/net_xxx.s

   1: /*
   2:  * Copyright (c) 1988 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)net_xxx.s	1.3 (2.11BSD GTE) 1/12/95
   7:  */
   8: 
   9: #include "DEFS.h"
  10: #include "../machine/mch_iopage.h"
  11: 
  12: /*
  13:  * delay(usec)
  14:  *	long	usec;
  15:  *
  16:  * Delay (approximately) usec micro-seconds.  It really isn't very acurrate
  17:  * since we can be interrupted and take much longer than we intended, but
  18:  * that's alright - we just don't want to come home early ...
  19:  *
  20:  * Copied to the networking from the kernel (mch_xxx.s) so the network could
  21:  * do delays (if_qt.c).
  22:  */
  23: ENTRY(delay)
  24:         mov     2(sp),r0                / r0 = hiint(usec)
  25:         mov     4(sp),r1                / r1 = loint(usec)
  26:         ashc    $1,r0                   / sob's ~= 1/2 micro second,
  27:         beq     2f                      / oops, got passed a delay of 0L-leave
  28:         tst     r1
  29:         /*
  30: 	 * If the low int of the loop counter is zero, the double sob loop
  31: 	 * below will perform correctly, otherwise the high byte must be
  32: 	 * increment.
  33: 	 */
  34:         beq     1f
  35:         inc     r0                      / correct for looping
  36: 1:
  37:         sob     r1,1b                   / sit on our hands for a while ...
  38:         sob     r0,1b
  39: 2:
  40:         rts     pc
  41: 
  42: /*
  43:  * badaddr(addr, len)
  44:  *	caddr_t addr;
  45:  *	int len;
  46:  *
  47:  * See if accessing addr with a len type instruction causes a memory fault.
  48:  * Len is length os access (1=byte, 2=short, 4=long).  Returns 0 if the
  49:  * address is OK, -1 on error.  If either the address or length is odd use
  50:  * a byte test rather than a word test.
  51:  */
  52: ENTRY(badaddr)
  53:         mov     PS,-(sp)                / save current PS and set previous
  54:         bic     $30000,PS               /   mode = kernel
  55:         mfpd    *$nofault               / save current nofault and set up
  56:         mov     $4f,-(sp)               /   our own trap
  57:         mtpd    *$nofault
  58:         mov     10(sp),r0               / if the low bit of either the length
  59:         bis     6(sp),r0                /   or address is
  60:         asr     r0                      /   on then use a tstb
  61:         bcc     1f                      / br if word test to be used
  62:         tstb    *6(sp)                  / yes, just do a tstb on the address
  63:         br      2f
  64: 1:
  65:         tst     *6(sp)                  / no, try a tst ...
  66: 2:
  67:         clr     r0                      / we made it - return success
  68: 3:
  69:         mtpd    *$nofault               / restore previous fault trap
  70:         mov     (sp)+,PS                /   and PS
  71:         rts     pc                      / and return
  72: 4:
  73:         mov     $-1,r0                  / we faulted out - return failure
  74:         br      3b
  75: 
  76: 
  77: /*
  78:  * locc(mask, size, str)
  79:  * 	u_char mask;
  80:  * 	u_int size;
  81:  * 	u_char *str;
  82:  *
  83:  * Scan through str up to (but not including str[size]) stopping when a
  84:  * character equals mask.  Return number of characters left in str.
  85:  */
  86: ENTRY(locc)
  87:         mov     4(sp),r0                / r0 = size
  88:         beq     3f                      /   exit early if zero
  89:         mov     6(sp),r1                / r1 = str
  90:         mov     r2,-(sp)                / r2 = mask
  91:         mov     2+2(sp),r2
  92: 1:                                      / do
  93:         cmpb    (r1)+,r2                /   if (*str++ == mask)
  94:         beq     2f
  95:         sob     r0,1b                   / while (--size != 0)
  96: 2:
  97:         mov     (sp)+,r2                / restore registers
  98: 3:
  99:         rts     pc                      / and return size

Defined functions