PDP-10.its/src/mits_s/boot11.1

.lif  z %defin
	.title	BOOT11 support
	.sbttl	BOOT11 support: Definitions, Macros and Code

;;; ;;; General info:
;;; ;;; 	Raw chaos loader/debugger.  Useful for poking an 11 when it croaks
;;; ;;; 	and you wish to poke at it (better have a debugger).
;;; ;;; Usage:
;;; ;;; 	defdev bt,boot11,<
;;; ;;; 		loader <chaos-csr-address>
;;; ;;; 		>


.if  nz %defin

.macro loader chcsr
ld.csr==chcsr+0
ld.myn==chcsr+2
ld.wbf==chcsr+2
ld.rbf==chcsr+4
ld.rbc==chcsr+6
ld.xmt==chcsr+12
.endm

%ldrdn==100000
%lderr==040000
%ldrst==020000
%ldtcl==000400
%ldtdn==000200
%ldrcl==000010

ld%RFC==1
ld%ANS==5


.endc nz %defin

.iif nz %defin, .nlist		;don't list code if only doing definitions

.if   z %defin			;only do code if not defining symbols

	.sbttl	-- Code

%%==.
.=bootad
	br ld
.=dbugad
	jmp db

ldtemp==%0			;temp
ldhstb==%1			;host table
ldaddr==%2			;load address
ldcoun==%3			;load count
ldrpcn==%4			;rep count (timeout)
ldwbuf==%5			;write buffer
ldrbuf==%6			;read buffer

ld:	reset
	mov #10$,sp
	rti

10$:				;stack points here for priority setting hack
	20$			;return address
	340			;priority 7

20$:	mov #%ldrst,@#ld.csr	;reset the board
	mov #%ldrcl+%ldtcl,@#ld.csr	;clear reciever and Xmitter
	mov #ld.rbf,ldrbuf
	mov #ld.wbf,ldwbuf
	loop <
	  mov #ldhstt,ldhstb
	  loop <
	    clr ldrpcn
	    loop <
	      bit #%ldrdn,@#ld.csr
	      if ne,<
	        br ldgpkt	;pseudo call
ldgret:		>
	      dec ldrpcn
	      rptl ne
	      >
ldsrfc:	    loop <		;no loop, just conceptual
	      loop <
		bit #%ldtdn,@#ld.csr	;Xmitter ready?
		rptl eq		;loop until ready
		>
	      bis #%ldtcl,@#ld.csr

	      mov #ld%rfc_8,(ldwbuf)	;opcode RFC
	      mov #ldslen,(ldwbuf)	;length of contact name
	      mov (ldhstb)+,(ldwbuf)	;destination host
	      clr (ldwbuf)	;his index
	      mov @#ld.myn,(ldwbuf)	;my address
	      mov #400,(ldwbuf)	;nice vanilla index
	      clr (ldwbuf)	;packet number
	      clr (ldwbuf)	;ack number

	      mov #ldcstr,ldtemp	;contact string
	      loop <
		mov (ldtemp)+,(ldwbuf)
		tst (ldtemp)
		rptl ne
		>
	      clr (ldwbuf)	;braodcast to everybody on subnet
	      tst @#ld.xmt	;send the packet
	      >			;end ldsrfc
	    tst (ldhstb)
	    rptl ne
	    >
	  rptl
	  >
ldhstt:
	1440			;mc
	2026			;ai
	5542			;ee
	3120			;vx
	0

ldcstr:	.ascii /11LOAD/
  ldslen==.-ldcstr
	.even
	.word 0			;force a zero word

ldgpkt:	bit #%lderr,@#ld.csr
	if ne,<
10$:	  bis #%ldrcl,@#ld.csr
	  br ldgret
	  >
	mov @#ld.rbc,ldcoun
	inc ldcoun
	bit #17,ldcoun
	bne 10$
	cmp (ldrbuf),#ld%rfc_8	;check opcode
	bne 10$
	mov (ldrbuf),ldcoun	;get the length
	bic #170000,ldcoun	;without the forwarding count
	cmp (ldrbuf),@#ld.myn	;for me?
	bne 10$
	tst (ldrbuf)		;my index (0)

	loop <			;set up ans packet
	  bit #%ldtdn,@#ld.csr
	  rptl eq
	  >
	bis #%ldtcl,@#ld.csr
	mov #ld%ans_8,(ldwbuf)
	clr (ldwbuf)		;length of data region
	mov (ldrbuf),(ldwbuf)	;his address
	mov (ldrbuf),(ldwbuf)	;his index
	mov @#ld.myn,(ldwbuf)	;my address
	clr (ldwbuf)		;no connection, so no index
	clr (ldwbuf)		;packet #
	clr (ldwbuf)		;and ack #
				;ANS packet is now ready

	cmp (ldrbuf),(ldrbuf)	;skip packet # and ack #
	cmp (ldrbuf),#<'L+<'D_8>>	;LD
	if ne,<
20$:	  bis #%ldtcl,@#ld.csr
	  br 10$
	  >
	cmp (ldrbuf),#<40+<40_8>>	;space,,space
	bne 20$
	mov (ldrbuf),ldaddr		;get deposit address
	sub #6,ldcoun		;count six bytes read
	blt 20$			;oops, packet too short
	if eq,<
	  bit #1,ldaddr
	  if ne,<halt>		;if odd just stop (or try to)
	  jmp (ldaddr)		;if even, go there
	  >
	loop <
	  mov (ldrbuf),ldtemp
	  movb ldtemp,(ldaddr)+
	  dec ldcoun
	  exitl eq
	  swab ldtemp
	  movb ldtemp,(ldaddr)+
	  dec ldcoun
	  rptl ne
	  >
	tst (ldrbuf)		;skip first hardware word
	mov (ldrbuf),(ldwbuf)	;he who delivereth this packet
				;shall receiveth mine.
	tst (ldrbuf)
	bit #%lderr,@#ld.csr	;bit count after error?
	bne 20$			;oops, who knows what happened
	tst @#ld.xmt		;send the ANS poacket on its way
	clr ldrpcn		;reset repetition count
	br 10$			;clear receiver and return



dbcnnm=ldhstb			;reuse a register

db:	mov %0,@#500
	mov #502,%0
	mov %1,(%0)+
	mov %2,(%0)+
	mov %3,(%0)+
	mov %4,(%0)+
	mov %5,(%0)+
	mov %6,(%0)+
	mov #4$,sp
	rti

4$:				;stak points here for priority setting hack
	6$			;return address
	340			;priority 7

6$:
	mov #ld.csr,ldtemp
	mov #ld.rbf,ldrbuf
	mov #ld.wbf,ldwbuf
	mov #%ldrst,(ldtemp)
	mov #%ldrcl+%ldtcl,(ldtemp)	;clear reciever and Xmitter
	loop <
	  bit #%ldrdn,(ldtemp)
	  rptl eq
	  bit #%lderr,(ldtemp)
	  if ne,<
10$:	    bis #%ldrcl,(ldtemp)
	    rptl
	    >
	  mov @#ld.rbc,ldcoun
	  inc ldcoun
	  bit #17,ldcoun
	  bne 10$
	  cmp (ldrbuf),#ld%rfc_8	;check opcode
	  bne 10$
	  tst (ldrbuf)		;punt the count
	  cmp (ldrbuf),@#ld.myn
	  bne 10$
	  tst (ldrbuf)

	  loop <
	    bit #%ldtdn,(ldtemp)
	    rptl eq
	    >
	  bis #%ldtcl,(ldtemp)
	  mov #ld%ans_8,(ldwbuf)
	  mov #2,(ldwbuf)
	  mov (ldrbuf),(ldwbuf)
	  mov (ldrbuf),(ldwbuf)
	  mov @#ld.myn,(ldwbuf)
	  clr (ldwbuf)
	  clr (ldwbuf)
	  clr (ldwbuf)


	  cmp (ldrbuf),(ldrbuf)
	  mov (ldrbuf),dbcnnm
	  cmp (ldrbuf),#<40+<40_8>>	;space,,space
	  if ne,<
20$:	    bis #%ldtcl,(ldtemp)
	    br 10$
	    >
	  loop <
	    cmp dbcnnm,#<'e+<'x_8>>
	    if eq,<
	      mov @(ldrbuf),(ldwbuf)
	      exitl
	      >
	    cmp dbcnnm,#<'d+<'p_8>>
	    if eq,<
	      mov (ldrbuf),@(ldrbuf)
	      clr (ldwbuf)
	      exitl
	      >
	    cmp dbcnnm,#<'g+<'o_8>>
	    if eq,<jmp @(ldrbuf)>
	    br 20$
	    >
	  tst (ldrbuf)
	  mov (ldrbuf),(ldwbuf)
	  tst (ldrbuf)
	  bit #%lderr,(ldtemp)
	  bne 20$
	  tst @#ld.xmt
	  br 10$
	  >

.=%%

btini:	return

.endc %defin

.iif nz %defin, .list		;start listing as usual


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