gno/sys/fileport/nullport/port.macros

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;
; Copyright (C) Kopriha Software, 1990 - 1991
; All rights reserved.
; Licensed material -- property of Kopriha Software
;
; This software is made available solely pursuant to the terms
; of a Kopriha Software license agreement which governs its use.
;
;
; The following macros (port_routine/port_return) are support
; routines for IIGS port drivers.
;
;
; Macros: port_routine (<length>:<parm name>[,...])[,<work size>]
; - Enter a port driver routine
;
; port_return <length>:<return name>[,<completion routine>]
; - Exit a port driver routine
; - This macro must be followed by an RTL. By coding the
; macro this way you can customize the return (some, but
; not all port driver routines must return after a CMP #1.
; See the source to port.asm for the details).
;
;
; Note: These macros are derived from the csubroutine/creturn
; macros supplied with Orca/C (on the demos disk).
;
MACRO
&lab port_subroutine &parms,&work
&lab anop Places the label from macro invocation
aif c:&work,.a If there is a work parm goto .a
lclc &work Local define work a string
&work setc 0 Set work to zero
.a .a
gbla &totallen Global define totallen
gbla &worklen Global define worklen
gbla &PClen Global define length of PC
&worklen seta &work Set worklen = work (type conversion)
&totallen seta 0 Set totallen to zero
&PClen seta 8 Set PC length to 8 (6(rtnPC*2)+1(direct page)+1(data bank))
aif c:&parms=0,.e If there are no parms to routine then goto .e
lclc &len Local define char len
lclc &p Local define char p
lcla &i Local define int i
&i seta 1 i = 1
.b .b
&p setc &parms(&i) p = parms[i]
&len amid &p,2,1 len = substr(p,2,1)
aif "&len"=":",.c if len == ':' goto .c
&len amid &p,1,2 len = substr(p,1,2) {First 2 chars}
&p amid &p,4,l:&p-3 p = substr(p,4,strlen(p)-3) {get name}
ago .d goto .d
.c .c
&len amid &p,1,1 len = substr(p,1,1) {only first char}
&p amid &p,3,l:&p-2 p = substr(p,3,strlen(p)-2) {get name}
.d .d We have a name and its length
&p equ &totallen+&PClen+&work {name} equ totallen+PClen+work
&totallen seta &totallen+&len totallen = totallen+len (length of parm)
&i seta &i+1 i = i + 1
aif &i<=c:&parms,^b if i<#parms goto b (backwards goto)
.e .e All parms setup (equ'd)
tsc get stack pointer
aif &work=0,.f If you need work space...
sec add it onto the stack pointer
sbc #&work
tcs
.f Stack is setup by here...
phd Save the direct page
tcd Set direct page == stack ptr
mend Thus lda parm is a direct page reference...
MACRO
&lab port_return &returnparm,&comproutine
;
; Parse the return parameter (if defined).
;
&lab anop Place any label from macro invocation
lclc &len Local create len
aif c:&returnparm,.a If there is a parameter goto .a
lclc &returnparm Local create r (for parm length)
&returnparm setc 0 Set returnparm to zero
&len setc 0 Set len to zero
ago .h Goto skip arguement parsing
.a .a We have a parameter - parse it!
&len amid &returnparm,2,1 len = substr(r,2,1)
aif "&len"=":",.b if (len == ':') goto .b
&len amid &returnparm,1,2 len = substr(r,1,2)
&returnparm amid &returnparm,4,l:&returnparm-3 r = substr(r,4,strlen(r)-3)
ago .c goto .c
.b .b One character length...
&len amid &returnparm,1,1 len = substr(r,1,1)
&returnparm amid &returnparm,3,l:&returnparm-2 r = substr(3,1,strlen(r)-2)
;
; Get the return parameter - if we have something to
; return. The return parameter can be 2,4 or 10 bytes
; (IE: Word, Long or Sane #).
;
.c
aif &len=0,.h If len == 0 then skip this...
aif &len<>2,.d if len != 2 goto .d
ldy &returnparm LDY <parm name>
ago .h goto .h
.d .d Not length == 2
aif &len<>4,.e if length != 4 goto .e
ldx &returnparm+2 LDX <parm name>+2 (high byte)
ldy &returnparm LDY <parm name> (low byte)
ago .h goto .h
.e .e Not length == 4
aif &len<>10,.g if length != 10 (IE: Sane #) goto .g
ldx #^&returnparm LDX #^<parm name> (high byte)
ldy #&returnparm LDY #<parm name> (low byte)
&len setc 4 We're returning a pointer...len 4
ago .h goto .h
.g .g Not sane # (hehehe)
mnote 'Not a valid return length',16 Print error}
mexit Oops... stop here
;
; Setup the completion routine - if there is one.
;
.h
aif c:&comproutine=0,.m
;
; Ok, lets setup the completion routine JSR (but only if its not NIL)
;
stz cjmp&SYSCNT+1 Clear the completion routine address
stz cjmp&SYSCNT+2 (all three words of it...)
;
lda &comproutine
ora &comproutine+1 'OR' the other bits in...
beq compa&SYSCNT If its NIL, then return to our caller.
;
; Looks non-NIL to me. Setup the completion routine call and then do it.
; (Ug... self modifying code... Its the easy solution for now...)
;
lda &comproutine Get low 2 bytes
sta cjmp&SYSCNT+1 Save them in our JSR instruction
lda &comproutine+1 Get the high bytes (actually,
sta cjmp&SYSCNT+2 just the bank byte...)
compa&SYSCNT anop
;
; Setup the return parameters on the stack (if any)
;
.m
aif &len<>2,.k If return nothing, goto .j
sty &worklen+&totallen+&PClen-&len
.k
aif &len<>4,.j
stx &worklen+&totallen+&PClen-&len Store low byte
sty &worklen+&totallen+&PClen-&len+2 Store high byte
.j
;
; If the return PCs need to be moved, then lets move
; them... the determination is based on if we have
; to remove parameters from the stack.
; Note: The order of the moving these PCs is significant!
; We must move the PCs in the order coded... any other
; may cause the first store to overwrite part of the
; PCs before moving them.
;
aif &totallen=0,.i if no parms to port_routine, goto .i
aif &totallen-&len=0,.i No sense in moving PCs nowhere...
lda &worklen+6 Copy return PCs (both of them)
sta &worklen+&totallen+6-&len
lda &worklen+4
sta &worklen+&totallen+4-&len
lda &worklen+2
sta &worklen+&totallen+2-&len
.i
;
; If there is a possible completion routine, then
; generate the code to check if it actually exists
; and if it does then call it (jsl) - otherwise rtl.
;
aif c:&comproutine=0,.p
;
; Ok, lets go to the completion routine JSR (but only if its not NIL)
;
lda cjmp&SYSCNT+1 Is there a completion routine?
ora cjmp&SYSCNT+2 'OR' the rest of the address...
beq compb&SYSCNT If its NIL, then return to our caller.
.i
;
; Looks non-NIL to me. Setup the completion routine call and then do it.
; (Ug... self modifying code... Its the easy solution for now...)
;
clc Clear carry - no errors on this call
lda #0 (Also need zero in ac for no error!)
cjmp&SYSCNT jsr >123456 Jmp to the completion routine
compb&SYSCNT anop (Jsl would come back to a rtl, may as well just go there)
.p
;
; If we have to then it is time to adjust the stack pointer
; (also get the direct page/data bank restored for our caller)
;
pld Restore the direct page
plb Restore the data bank
aif &worklen+&totallen-&len=0,.o If we aren't changing the stack ptr
tsc Fix the stack pointer
clc ...
adc #&worklen+&totallen-&len ...
tcs ...
.o
clc Clear carry - no errors on this call
lda #0 (Also need zero in ac for no error!)
mend