fkernel26bit

\
\ ANS Forth kernel for ARM 3 machines  Martin Läuter 26bit mode
\
\ modified for strongarm 2007 Alban Read
\

decimal
here: coldstart 0 , \ branch to cold, will be patched later
here: memtotal  0 , \ total memory available
here: retstack  0 , \ desired return stack size
here: datstack  0 , \ desired data stack size
here: filebuff  0 , \ desired file buffer size
here: commline  0 , \ commandline address

here: thisfile
0 , ," FKERNEL"

vocabulary forth
\ Hash-value for " FORTH" is &10

forth definitions meta

label dovar
  stmfd sp !, { tos }
  bic tos, link, # &fc000003
  next c; meta

label docon
  stmfd sp !, { tos }
  bic link, link, # &fc000003
  ldr tos, [ link ]
  next c;


assembler dovar meta constant dovar
assembler docon meta constant docon


labcreate docol
  stmfd rp !, { ip }
  bic ip, link, # &fc000003
next c;

labcreate dodoes
  stmfd sp !, { tos }
  mov tos, r0
  stmfd rp !, { ip }
  bic ip, link, # &fc000003
next c;

labcreate dovalue
  stmfd sp !, { tos }
  bic link, link, # &fc000003
  ldr tos, [ link ]
next c;

labcreate dovalue!
  bic link, link, # &fc000003
  str tos, [ link, # -8 ]
  ldmfd sp !, { tos }
next c;

labcreate dovalue+!
  bic link, link, # &fc000003
  ldr r0, [ link, # -12 ]
  add r0, tos, r0
  str r0, [ link, # -12 ]
  ldmfd sp !, { tos }
next c;

labcreate do2value
  stmfd sp !, { tos }
  bic link, link, # &fc000003
  ldr tos, [ link ]
  ldmfd tos, { tos, link }
  stmfd sp !, { link }
next c; meta

variable lp

labcreate dolocal
  stmfd sp !, { tos }
  bic link, link, # &fc000003
  ldr tos, [ link ]
  ldr r0, lp
  ldr tos, [ r0, tos ]
next c;

labcreate dolocal!
  bic link, link, # &fc000003
  ldr r0, [ link, # -8 ]
  ldr r1, lp
  str tos, [ r1, r0 ]
  ldmfd sp !, { tos }
next c;

labcreate dolocal+!
  bic link, link, # &fc000003
  ldr r0, [ link, # -12 ]
  ldr r1, lp
  ldr r0, [ r1, r0 ]!
  add tos, tos, r0
  str tos, [ r1 ]
  ldmfd sp !, { tos }
next c;

labcreate docolp
  ldr r0, lp
  stmfd rp !, { r0, ip }
  str rp, lp
  bic ip, link, # &fc000003
  ldr r0, [ ip ], # 4
  and r1, r0, # &ff
  sub rp, rp, r1, lsl # 2
  mov r0, r0, lsr # 8
  and s r0, r0, # &ff
  0<> if
    begin
      stmfd rp !, { tos }
      ldmfd sp !, { tos }
      sub s r0, r0, # 1
    0= until
  then
next c; meta


variable defer-list

variable loadfile      thisfile loadfile !-t

code exitp
  ldr rp, lp
  ldmfd rp !, { r0, ip }
  str r0, lp
next c;

code unnestp
  ldr rp, lp
  ldmfd rp !, { r0, ip }
  str r0, lp
next c;

code exit      ( -- )
  ldmfd rp !, { ip }
next c;

code unnest    ( -- ) \ Same as EXIT
  ldmfd rp !, { ip }
next c;

code noop      ( -- ) \  Does nothing  (No-Operation)
next c;


code lit
  stmfd sp !, { tos }
  ldmfd ip !, { tos, pc }
c;

\ Execute the word whose CFA is on the stack.
code execute   ( cfa -- )
  mov r0, tos
  ldmfd sp !, { tos }
  mov pc, r0 c;

code pause
  mov r0, r0
next c;

code branch    ( -- ) \ an unconditional branch
  ldr ip, [ ip ]
next c;

code ?branch   ( f -- )  \ branch if f is zero
  teq tos, # 0
  ldmfd sp !, { tos }
  ldmfd ne ip !, { r0, pc }
  ldr ip, [ ip ]
next c;

code _begin
next c;

code _until
  teq tos, # 0
  ldmfd sp !, { tos }
  ldmfd ne ip !, { r0, pc }
  ldr ip, [ ip ]
next c;

code _again
  ldr ip, [ ip ]
next c;

code _while
  teq tos, # 0
  ldmfd sp !, { tos }
  ldmfd ne ip !, { r0, pc }
  ldr ip, [ ip ]
next c;

code _repeat
  ldr ip, [ ip ]
next c;

code _then
next c;

code _case
next c;

code _endcase
  ldmfd sp !, { tos }
next c;

code _of
  mov r0, tos
  ldmfd sp !, { tos }
  cmp r0, tos
  ldr ne ip, [ ip ]
  next ne
  ldmfd sp !, { tos }
  ldmfd ip !, { r0, pc } c;

code _endof   ( -- ) \ an unconditional branch
  ldr ip, [ ip ]
next
c;

code (do)      ( lim sta -- ) \ Primitive form of DO
  mov r3, tos
  ldmfd sp !, { r1, tos }
  ldr r2, [ ip ], # 4
  add r1, r1, # &80000000
  sub r0, r3, r1
  stmfd rp !, { r0, r1, r2 }
next c;

code (?do)     ( lim sta -- ) \ Primitive form of ?DO
  mov r3, tos
  ldmfd sp !, { r1, tos }
  cmp r3, r1
  ldr ne r2, [ ip ], # 4
  add ne r1, r1, # &80000000
  sub ne r0, r3, r1
  stmfd ne rp !, { r0, r1, r2 }
  next ne
  ldr ip, [ ip ]
next c;

\ Clean up Return Stack so we can EXIT from DO-loop.
code unloop    ( -- )
  add rp, rp, # 12
next c;

code (loop)    ( -- )  \ Primitive form of LOOP
  ldr r0, [ rp ]
  add s r0, r0, # 1
  str vc r0, [ rp ]
  ldr vc ip, [ ip ]
  next vc
  add rp, rp, # 12
  ldmfd ip !, { r0, pc } c;

code (+loop)   ( n -- )  \ Primitive form of +LOOP
  ldr r0, [ rp ]
  add s r0, r0, tos
  ldmfd sp !, { tos }
  str vc r0, [ rp ]
  ldr vc ip, [ ip ]
  next vc
  add rp, rp, # 12
  ldmfd ip !, { r0, pc } c;

code bounds    ( n1 n2 --- n3 n4 )  \ Calculate limits used in DO-loop
  mov r0, tos
  ldr tos, [ sp ]
  add r0, tos, r0
  str r0, [ sp ]
next c;

code i         ( -- n ) \ get index of the innermost loop
  stmfd sp !, { tos }
  ldr tos, [ rp ]
  ldr r0, [ rp, # 4 ]
  add tos, tos, r0
next c;

code j         ( -- n ) \ get index of the second most inner loop.
  stmfd sp !, { tos }
  ldr tos, [ rp, # 12 ]
  ldr r0, [ rp, # 16 ]
  add tos, tos, r0
next c;

code leave       ( -- )
  add rp, rp, # 12
  ldr ip, [ rp, # -4 ]
next c;

code ?leave    ( f -- )
  orr s tos, tos, tos
  ldmfd sp !, { tos }
  next eq
  add rp, rp, # 12
  ldr ip, [ rp, # -4 ]
next c;

variable sp0
variable rp0
variable hld
variable base
variable handler
variable msg
variable dp


\ sync the last few pages
code syncCode
  ldr r0, dp
  mov r1, # 0
  begin
    tst r0, # 3
  0<> while
    strb r1, [ r0 ], # 1
  repeat
  mov r2, r0
  sub r1, r0, # 8192
  mov r0, # 1
  swi " OS_SynchroniseCodeAreas"
next c;

code here
  stmfd sp !, { tos }
  ldr tos, dp
next c;

code allot
  ldr r0, dp
  add r0, r0, tos
  str r0, dp
  ldmfd sp !, { tos }
  ldr r0, dp
next c;

code compile,
  ldr r0, dp
  str tos, [ r0 ], # 4
  str r0, dp
  ldmfd sp !, { tos }
next c;

code ,
  ldr r0, dp
  str tos, [ r0 ], # 4
  str r0, dp
  ldmfd sp !, { tos }
next c;

code c,
  ldr r0, dp
  strb tos, [ r0 ], # 1
  str r0, dp
  ldmfd sp !, { tos }
next c;

code w,
  ldr r0, dp
  strb tos, [ r0 ], # 1
  mov tos, tos, lsr # 8
  strb tos, [ r0 ], # 1
  str r0, dp
  ldmfd sp !, { tos }
next c;

code compile
  ldr r0, dp
  ldmfd ip !, { r1, link }
  str r1, [ r0 ], # 4
  str r0, dp
  mov pc, link c;

code align
  ldr r0, dp
  mov r1, # 0
  begin
    tst r0, # 3
  0<> while
    strb r1, [ r0 ], # 1
  repeat
  str r0, dp
next c;


code aligned
  add tos, tos, # 3
  bic tos, tos, # 3
next c;

labcreate m0cfa
  ldr r0, lp
  stmfd rp !, { r0, op, ip }
  str rp, lp
  bic ip, link, # &fc000003
  \ mov ip, link
  mov op, tos
  ldmfd sp !, { tos }
  ldr r0, [ ip, # 4 ]!
  and r1, r0, # &ff
  sub rp, rp, r1, lsl # 2
  mov s r0, r0, lsr # 8
  0<> if
    begin
      stmfd rp !, { tos }
      ldmfd sp !, { tos }
      sub s r0, r0, # 1
    0= until
  then
  add ip, ip, # 4
next c;

labcreate m1cfa
  ldr r0, lp
  ldr r1, [ ip ], # 4
  stmfd rp !, { r0, op, ip }
  add op, r1, op
  str rp, lp
  bic ip, link, # &fc000003
  \ mov ip, link
  ldr r0, [ ip ], # 4
  and r1, r0, # &ff
  sub rp, rp, r1, lsl # 2
  mov s r0, r0, lsr # 8
  0<> if
    begin
      stmfd rp !, { tos }
      ldmfd sp !, { tos }
      sub s r0, r0, # 1
    0= until
  then
next c; meta

code exitm
  ldr rp, lp
  ldmfd rp !, { r0, op, ip }
  str r0, lp
next c;

code unnestm
  ldr rp, lp
  ldmfd rp !, { r0, op, ip }
  str r0, lp
next c;

code ^base
  stmfd sp !, { tos }
  mov tos, op
next c;

labcreate (iv@)
  stmfd sp !, { tos }
  bic r0, link, # &fc000003
  ldr r0, [ r0 ]
  ldr tos, [ r0, op ]
next c;

labcreate (iv!)
  bic r0, link, # &fc000003
  ldr r0, [ r0, # -8 ]
  str tos, [ r0, op ]
  ldmfd sp !, { tos }
next c;

labcreate (iv+!)
  bic r0, link, # &fc000003
  ldr r0, [ r0, # -12 ]
  ldr r1, [ r0, op ]
  add tos, tos, r1
  str tos, [ r0, op ]
  ldmfd sp !, { tos }
next c;

labcreate (iv[]@)
  bic r0, link, # &fc000003
  ldr r0, [ r0 ]
  add r0, r0, op
  ldr tos, [ r0, tos, lsl # 2 ]
next c;

labcreate (iv[]!)
  bic r0, link, # &fc000003
  ldr r0, [ r0, # -8 ]
  add r0, r0, tos, lsl # 2
  ldmfd sp !, { r1, tos }
  str r1, [ r0, op ]
next c;

labcreate (iv[]+!)
  bic r0, link, # &fc000003
  ldr r0, [ r0, # -12 ]
  add r0, r0, tos, lsl # 2
  ldmfd sp !, { r2, tos }
  ldr r1, [ r0, op ]!
  add r1, r1, r2
  str r1, [ r0 ]
next c;

labcreate doobj
  stmfd sp !, { tos }
  bic tos, link, # &fc000003
  add tos, tos, # 4
next c;


code ((findm))
  ldmfd sp !, { r0 }
  begin
    ldr tos, [ tos ]
    teq tos, # 0
    next eq
    ldr r1, [ tos, # 4 ]
    cmp r0, r1
  0= until
  add tos, tos, # 8
  stmfd sp !, { tos }
  mvn tos, # 0
next c;

code hash   ( ad cnt -- hash )
  ldmfd sp !, { r0 }
  mov r1, tos
  mov tos, # 0
  begin
    ldrb r2, [ r0 ], # 1
    eor tos, r2, tos, lsl # 1
    sub s r1, r1, # 1
  0= until
next c;

code init-locals
  ldr r0, lp
  stmfd rp !, { r0 }
  str rp, lp
  ldr r0, [ ip ], # 4
  and r1, r0, # &ff
  sub rp, rp, r1, lsl # 2
  mov r0, r0, lsr # 8
  and s r0, r0, # &ff
  0<> if
    begin
      stmfd rp !, { tos }
      ldmfd sp !, { tos }
      sub s r0, r0, # 1
    0= until
  then
next c;

code unparms
  ldr rp, lp
  ldmfd rp !, { r0 }
  str r0, lp
next c;

code _localalloc
  sub rp, rp, tos
  bic rp, rp, # 3
  mov tos, rp
next c;

code drop      ( n -- )
  ldmfd sp !, { tos }
next c;

code dup       ( n -- n n )
  stmfd sp !, { tos }
next c;

code swap      ( n1 n2 -- n2 n1 )
  ldr r0, [ sp ]
  str tos, [ sp ]
  mov tos, r0
next c;


code over      ( n1 n2 -- n1 n2 n1 )
  stmfd sp !, { tos }
  ldr tos, [ sp, # 4 ]
next c;

code rot       ( n1 n2 n3 -- n2 n3 n1 )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  stmfd sp !, { r0, r1 }
next c;

code -rot      ( n1 n2 n3 -- n3 n1 n2 )
  ldmfd sp !, { r0, r1 }
  stmfd sp !, { r1, tos }
  mov tos, r0
next c;

code ?dup      ( n -- 0 | n n )
  orr s tos, tos, tos
  stmfd ne sp !, { tos }
next c;

code -dup
 orr s tos, tos, tos
 stmfd ne sp !, { tos }
next c;

code nip       ( n1 n2 -- n2 )
  add sp, sp, # 4
next c;

code tuck      ( n1 n2 -- n2 n1 n2 )
  ldmfd sp !, { r0 }
  stmfd sp !, { r0, tos }
next c;

code pick      ( nk ... n0 k -- nk ... n0 nk )
  ldr tos, [ sp, tos, lsl # 2 ]
next c;

code depth     ( -- n )
  stmfd sp !, { tos }
  adr tos, sp0
  ldr tos, [ tos ]
  sub tos, tos, sp
  mov tos, tos, asr # 2
next c;

\ Push the address of the top element on the stack (prior to push).
code sp@       ( -- n )
  stmfd sp !, { tos }
  mov tos, sp
next c;

\ Set the parameter stack pointer to specified value.
code sp!       ( n -- )
  mov sp, tos
  ldmfd sp !, { tos }
next c;


\ address of the top element of the return stack
code rp@       ( -- ad )
  stmfd sp !, { tos }
  mov tos, rp
next c;

\ Set the return stack pointer to ad.
code rp!       ( ad -- )
  mov rp, tos
  ldmfd sp !, { tos }
next c;

code >r        ( n -- )
  stmfd rp !, { tos }
  ldmfd sp !, { tos }
next c;

code r>        ( -- n )
  stmfd sp !, { tos }
  ldmfd rp !, { tos }
next c;

code r@        ( -- n )
  stmfd sp !, { tos }
  ldr tos, [ rp ]
next c;

code dup>r     ( n -- n )
  stmfd rp !, { tos }
next c;

code r>drop    ( -- )
  add rp, rp, # 4
next c;

code 2>r       ( d -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  stmfd rp !, { r0, r1 }
next c;

code 2r>       ( -- d )
  ldr r0, [ rp, # 4 ]
  stmfd sp !, { r0, tos }
  ldr tos, [ rp ], # 8
next c;

code 2r@       ( -- d )
  ldr r0, [ rp, # 4 ]
  stmfd sp !, { r0, tos }
  ldr tos, [ rp ]
next c;

code @         ( ad -- n )   \ Fetch a 32 bit value from addr
  ldr tos, [ tos ]
next c;

code !         ( n ad -- )   \ Store value n into the address addr
  mov r0, tos
  ldmfd sp !, { r1, tos }
  str r1, [ r0 ]
next c;

code +!        ( n ad -- )
  mov r1, tos
  ldmfd sp !, { r0, tos }
  ldr r2, [ r1 ]
  add r2, r2, r0
  str r2, [ r1 ]
next c;

code u/ ( n n1 -- n2 )
 mov r1, tos
 ldmfd sp !, { r0 }
 udiv tos, r0, r1
next c;

code s/ ( n n1 -- n2 )
 mov r1, tos
 ldmfd sp !, { r0 }
 sdiv tos, r0, r1
next c;

code c@        ( ad -- c )
  ldrb tos, [ tos ]
next c;

code c!        ( c ad -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  strb r1, [ r0 ]
next c;

code c+!       ( c ad -- )
  mov r1, tos
  ldmfd sp !, { r0, tos }
  ldrb r2, [ r1 ]
  add r2, r2, r0
  strb r2, [ r1 ]
next c;

\ non aligned fetch
code na@       ( ad -- n )
  ldrb r0, [ tos ]
  ldrb r1, [ tos, # 1 ]
  add r0, r0, r1, lsl # 8
  ldrb r1, [ tos, # 2 ]
  add r0, r0, r1, lsl # 16
  ldrb r1, [ tos, # 3 ]
  add tos, r0, r1, lsl # 24
next c;

\ non aligned store
code na!       ( n ad -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  strb r1, [ r0 ], # 1
  mov r1, r1, lsr # 8
  strb r1, [ r0 ], # 1
  mov r1, r1, lsr # 8
  strb r1, [ r0 ], # 1
  mov r1, r1, lsr # 8
  strb r1, [ r0 ], # 1
next c;

code call@     ( ad -- cfa )
  ldr r0, [ tos ], # 8
  mov r1, r0, lsr # 25
  cmp r1, # 117
  mov ne tos, r0
  next ne
  mov r0, r0, lsl # 8
  mov r0, r0, asr # 6
  add tos, tos, r0
next c;

\ 16 bit (half word) fetch
code w@        ( ad -- n )
  ldrb r0, [ tos ]
  ldrb r1, [ tos, # 1 ]
  add tos, r0, r1, lsl # 8
next c;

\ Fetch a 16 bit value from addr
code sw@        ( ad -- n )
  ldrb r0, [ tos ]
  ldrb r1, [ tos, # 1 ]
  add tos, r0, r1, lsl # 8
  mov tos, tos, lsl # 16
  mov tos, tos, asr # 16
next c;

\ Store 16 bit value n into the address addr
code w!        ( n ad -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  strb r1, [ r0 ]
  mov r1, r1, lsr # 8
  strb r1, [ r0, # 1 ]
next c;

code w+!       ( n ad -- )
  mov r1, tos
  ldmfd sp !, { r0, tos }
  ldrb r3, [ r1 ]
  ldrb r2, [ r1, # 1 ]
  add r2, r3, r2 lsl # 8 ]
  add r2, r2, r0
  strb r2, [ r1 ]
  mov r2, r2, lsr # 8
  strb r2, [ r1, # 1 ]
next c;

\ 4 constant cell

code cell
  stmfd sp !, { tos }
  mov tos, # 4
next c;

code cells     ( n1 -- n2 )
  mov tos, tos, lsl # 2
next c;

code cells+    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  add tos, r0, tos, lsl # 2
next c;

code cells-    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  sub tos, r0, tos, lsl # 2
next c;

code cell+     ( n1 -- n2 )
  add tos, tos, # 4
next c;

code cell-     ( n1 -- n2 )
  sub tos, tos, # 4
next c;

code +cells    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  add tos, tos, r0, lsl # 2
next c;

code -cells    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  sub tos, tos, r0, lsl # 2
next c;

code move      ( from to count -- )
  mov s r3, tos
  ldmfd sp !, { r0, r1, tos } \ to from
  next eq
  sub r2, r0, r1
  cmp r2, r3
  u>= if
    begin
      ldrb r2, [ r1 ], # 1
      strb r2, [ r0 ], # 1
      sub s r3, r3, # 1
    0= until
    next
  else
    add r0, r0, r3
    add r1, r1, r3
    sub r0, r0, # 1
    sub r1, r1, # 1
    begin
      ldrb r2, [ r1 ], # -1
      strb r2, [ r0 ], # -1
      sub s r3, r3, # 1
    0= until
    next
  then c;

code fill      ( ad cnt c -- )
  mov r0, tos
  ldmfd sp !, { r1, r2, tos }
  teq r1, # 0
  next eq
  begin
    strb r0, [ r2 ], # 1
    sub s r1, r1, # 1
  0= until
next c;

\ 32 constant bl

code bl
  stmfd sp !, { tos }
  mov tos, # 32
next c;

: erase        ( ad cnt -- )
    0 fill ;

: blank        ( ad cnt -- )
    bl fill ;

\ moves block of memory beginning at from !!! traditional !!!
code cmove     ( from to count -- )
  mov s r3, tos
  ldmfd sp !, { r0, r1, tos } \ count, to from
  next eq
  begin
    ldrb r2, [ r1 ], # 1
    strb r2, [ r0 ], # 1
    sub s r3, r3, # 1
  0= until
next c;

\ moves block of memory beginning at from+count-1 !!! traditional !!!
code cmove>    ( from to count -- )
  mov s r3, tos
  ldmfd sp !, { r0, r1, tos } \ count, to from
  next eq
  add r0, r0, r3
  add r1, r1, r3
  sub r0, r0, # 1
  sub r1, r1, # 1
  begin
    ldrb r2, [ r1 ], # -1
    strb r2, [ r0 ], # -1
    sub s r3, r3, # 1
  0= until
next c;

code and       ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  and tos, tos, r0
next c;

code or        ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  orr tos, tos, r0
next c;

code xor       ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  eor tos, tos, r0
next c;

code invert    ( n1 -- n2 )
  mvn tos, tos
next c;

code lshift    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  mov tos, r0, lsl tos
next c;

code rshift    ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  mov tos, r0, lsr tos
next c;

-1 constant true
 0 constant false



code incr      ( ad -- )
  ldr r0, [ tos ]
  add r0, r0, # 1
  str r0, [ tos ]
  ldmfd sp !, { tos }
next c;

code decr      ( ad -- )
  ldr r0, [ tos ]
  sub r0, r0, # 1
  str r0, [ tos ]
  ldmfd sp !, { tos }
next c;

code on        ( ad -- )
  mvn r0, # 0
  str r0, [ tos ]
  ldmfd sp !, { tos }
next c;

code off       ( ad -- )
  mov r0, # 0
  str r0, [ tos ]
  ldmfd sp !, { tos }
next c;

code toggle    ( ad byte -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  ldrb r2, [ r1 ]
  eor r2, r2, r0
  strb r2, [ r1 ]
next c;

code +         ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  add tos, tos, r0
next c;

code -         ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  sub tos, r0, tos
next c;

code negate    ( n1 -- n2 )
  rsb tos, tos, # 0
next c;

code abs       ( n1 -- n2 )
  eor s tos, tos, tos, asr # 32
  adc tos, tos, # 0
next c;

code 0
 stmfd sp !, { tos }
 eor tos, tos, tos
next c;

code 1
 stmfd sp !, { tos }
 mov tos, # 1
next c;

code 2
 stmfd sp !, { tos }
 mov tos, # 2
next c;

code 4
 stmfd sp !, { tos }
 mov tos, # 4
next c;


code 8
 stmfd sp !, { tos }
 mov tos, # 8
next c;


code 16
 stmfd sp !, { tos }
 mov tos, # 16
next c;

code 32
 stmfd sp !, { tos }
 mov tos, # 32
next c;

code 260
 stmfd sp !, { tos }
 mov tos, # 260
next c;



\ 0 constant 0
\ 1 constant 1

code 2*        ( n1 -- n2 )
  mov tos, tos, lsl # 1
next c;

code 4*        ( n1 -- n2 )
  mov tos, tos, lsl # 2
next c;

code 8*        ( n1 -- n2 )
  mov tos, tos, lsl # 3
next c;

code 16*        ( n1 -- n2 )
  mov tos, tos, lsl # 4
next c;

code 32*        ( n1 -- n2 )
  mov tos, tos, lsl # 5
next c;

code -32* ( n -- n' )
  mov tos, tos, lsl # 5
  rsb tos, tos, # 0
next c;


code 2/        ( n1 -- n2 )
  mov tos, tos, asr # 1
next c;

code 4/        ( n1 -- n2 )
  mov tos, tos, asr # 2
next c;

code 8/        ( n1 -- n2 )
  mov tos, tos, asr # 3
next c;

code 16/        ( n1 -- n2 )
  mov tos, tos, asr # 4
next c;

code 32/        ( n1 -- n2 )
  mov tos, tos, asr # 5
next c;

code u2/       ( n1 -- n2 )
  mov tos, tos, lsr # 1
next c;

code u4/       ( n1 -- n2 )
  mov tos, tos, lsr # 2
next c;

code u8/       ( n1 -- n2 )
  mov tos, tos, lsr # 3
next c;

code u16/       ( n1 -- n2 )
  mov tos, tos, lsr # 4
next c;

code u32/       ( n1 -- n2 )
  mov tos, tos, lsr # 5
next c;

code 10*      ( n1 -- n2 )
 mov r0, tos, lsl # 1
 add tos, tos, r0, lsl # 3
next c;

code ~10/       ( n1 -- n2 )
 mov r0, # 205
 mul r1, r0, tos
 mov tos, r1, lsr # 11
next c;

code 1+        ( n1 -- n2 )
  add tos, tos, # 1
next c;

code 2+        ( n1 -- n2 )
  add tos, tos, # 2
next c;

code 4+        ( n1 -- n2 )
  add tos, tos, # 4
next c;

code 8+        ( n1 -- n2 )
  add tos, tos, # 8
next c;

code 16+        ( n1 -- n2 )
  add tos, tos, # 16
next c;

code 32+        ( n1 -- n2 )
  add tos, tos, # 32
next c;

code 1-        ( n1 -- n2 )
  sub tos, tos, # 1
next c;

code d2*       ( d1 -- d2 )
  ldr r0, [ sp ]
  add s r0, r0, r0
  adc tos, tos, tos
  str r0, [ sp ]
next c;

code d2/       ( d1 -- d2 )
  ldmfd sp !, { r0 }
  mov s tos, tos, asr # 1
  mov r0, r0, rrx
  stmfd sp !, { r0 }
next c;

code um*       ( u1 u2 -- d )
  ldmfd sp !, { r0 }
  mov r2, r0, lsr # 16
  mov r1, tos, lsr # 16
  eor r0, r0, r2, lsl # 16
  eor tos, tos, r1, lsl # 16
  mul r4, r1, r2     \ hi
  mul r3, tos, r0    \ lo
  mul r2, tos, r2
  mul r1, r0, r1
  add s r0, r0, r1
  add cs r4, r4, # &10000
  add s r3, r3, r0, lsl # 16
  adc tos, r4, r0, lsr # 16
  stmfd sp !, { r3 }
next c;

code word-split ( u -- lo hi )
  mov r0, tos, lsl # 16
  mov r0, r0, lsr # 16
  stmfd sp !, { r0 }
  mov tos, tos, lsr # 16
next c;

code word-join ( lo hi -- n )
  ldmfd sp !, { r0 }
  add tos, r0, tos, lsl # 16
next c;

code 0=        ( n -- f )
  sub s tos, tos, # 1
  sbc tos, tos, tos
next c;

code 0<>       ( n -- f )
  orr s tos, tos, tos
  mvn ne tos, # 0
next c;

code 0<        ( n -- f )
  mov tos, tos, asr # 32
next c;

code 0>        ( n -- f )
  sub tos, tos, # 1
  mvn tos, tos, asr # 32
next c;

code =         ( n1 n2 -- f )
  ldmfd sp !, { r0 }
  cmp s r0, tos
  mvn eq tos, # 0
  mov ne tos, # 0
next c;

code <>        ( n1 n2 -- f )
  ldmfd sp !, { r0 }
  sub s tos, r0, tos
  mvn ne tos, # 0
next c;

code <         ( n1 n2 -- f )
  ldmfd sp !, { r0 }
  cmp r0, tos
  mvn lt tos, # 0
  mov ge tos, # 0
next c;

code >         ( n1 n2 -- f )
  ldmfd sp !, { r0 }
  cmp tos, r0
  mvn lt tos, # 0
  mov ge tos, # 0
next c;

code u<        ( u1 u2 -- f )
  ldmfd sp !, { r0 }
  sub s tos, r0, tos
  sbc tos, tos, tos
next c;

code u>        ( u1 u2 -- f )
  ldmfd sp !, { r0 }
  sub s tos, tos, r0
  sbc tos, tos, tos
next c;

code du<       ( ud1 ud2 -- f )
  ldmfd sp !, { r0, r1, r2 }
  sub s r2, r2, r0
  sbc s r1, r1, tos
  sbc tos, r2, r2
next c;

code umin      ( u1 u2 -- u3 )
  ldmfd sp !, { r0 }
  cmp tos, r0
  mov cs tos, r0
next c;

code min       ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  cmp tos, r0
  mov gt tos, r0
next c;

code umax      ( u1 u2 -- u3 )
  ldmfd sp !, { r0 }
  cmp tos, r0
  mov cc tos, r0
next c;

code max       ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  cmp tos, r0
  mov lt tos, r0
next c;

code 0max      ( n1 -- n2 )
  cmp tos, # 0
  mov lt tos, # 0
next c;

code between   ( n lo hi -- f ) \ true if lo<=n<=hi
  mov r2, tos
  mov tos, # 0
  ldmfd sp !, { r0, r1 }
  cmp r1, r2
  next gt
  cmp r0, r1
  mvn le tos, # 0
next c;

code within    ( n lo hi -- f ) \ true if lo<=n<hi
  mov r2, tos
  mov tos, # 0
  ldmfd sp !, { r0, r1 }
  cmp r1, r2
  next ge
  cmp r0, r1
  mvn le tos, # 0
next c;

code 2@        ( ad -- d )
  ldmfd tos, { r0, r1 }
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code 2!        ( d ad -- )
  mov r2, tos
  ldmfd sp !, { r0, r1, tos }
  stmea r2, { r0, r1 }
next c;

code 2drop     ( d -- )
  add sp, sp, # 4
  ldmfd sp !, { tos }
next c;

code 2dup      ( d -- d d )
  ldr r0, [ sp ]
  stmfd sp !, { r0, tos }
next c;

code 2swap     ( d1 d2 -- d2 d1 )
  ldmfd sp !, { r0, r1, r2 }
  stmfd sp !, { r0 }
  stmfd sp !, { r2, tos }
  mov tos, r1
next c;

code 2over     ( d1 d2 -- d1 d2 d1 )
  ldr r0, [ sp, # 8 ]
  stmfd sp !, { r0, tos }
  ldr tos, [ sp, # 12 ]
next c;

code 2rot      ( d1 d2 d3 -- d2 d3 d1 )
  ldmfd sp !, { r0, r1, r2, r3, r4 }
  stmfd sp !, { r0, r1, r2 }
  stmfd sp !, { r4, tos }
  mov tos, r3
next c;

code d+        ( d1 d2 -- d3 )
  ldmfd sp !, { r0, r1, r2 }
  add s r0, r0, r2
  adc tos, tos, r1
  stmfd sp !, { r0 }
next c;

code d-        ( d1 d2 -- d3 )
  ldmfd sp !, { r0, r1, r2 }
  sub s r0, r2, r0
  sbc tos, r1, tos
  stmfd sp !, { r0 }
next c;

code dnegate   ( d1 -- d2 )
  ldmfd sp !, { r0 }
  rsb s r0, r0, # 0
  rsc tos, tos, # 0
  stmfd sp !, { r0 }
next c;

code dabs      ( d1 -- d2 )
  tst tos, # &80000000
  next eq
  ldmfd sp !, { r0 }
  rsb s r0, r0, # 0
  rsc tos, tos, # 0
  stmfd sp !, { r0 }
next c;

code s>d       ( n -- d )
  stmfd sp !, { tos }
  mov tos, tos, asr # 32
next c;

code m*        ( n1 n2 -- d )
  ldmfd sp !, { r0 }
  eor r5, r0, tos
  tst r0, # &80000000
  rsb ne r0, r0, # 0
  tst tos, # &80000000
  rsb ne tos, tos, # 0
  mov r2, r0, lsr # 16
  mov r1, tos, lsr # 16
  eor r0, r0, r2, lsl # 16
  eor tos, tos, r1, lsl # 16
  mul r4, r1, r2     \ hi
  mul r3, tos, r0    \ lo
  mul r2, tos, r2
  mul r1, r0, r1
  add s r0, r2, r1
  add cs r4, r4, # &10000
  add s r3, r3, r0, lsl # 16
  adc tos, r4, r0, lsr # 16
  tst r5, # &80000000
  0<> if
    rsb s r3, r3, # 0
    rsc tos, tos, # 0
  then
  stmfd sp !, { r3 }
next c;

\ 1 2 3 * +
code *+ ( n1 n2 n3 -- n4  )
 mov r0, tos
 ldmfd sp !, { r1, r2 }
 mla tos, r0, r1, r2
next c;


code *         ( n1 n2 -- n3 )
  ldmfd sp !, { r0 }
  mul tos, r0, tos
next c;

label division
  add s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 4
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 8
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 12
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 16
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 20
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 24
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 28
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1
  sub cc r0, r0, tos
  adc s r1, r1, r1
  adc s r0, tos, r0, lsl # 1  \ 32
  sub cc r0, r0, tos
  adc tos, r1, r1
  mov pc, link c;

code um/mod    ( ud un -- urem uquot )
  ldmfd sp !, { r0, r1 }
  cmp r0, tos
  b cs 1 $
  rsb s tos, tos, # 0
  b eq 1 $
  bl division
  stmfd sp !, { r0 }
  next
1 $:
  mvn tos, # 0
  stmfd sp !, { tos }
next c;

code sm/rem
  ldmfd sp !, { r0, r1 }
  mov s r3, r0
  0< if
    rsb s r1, r1, # 0
    rsc r0, r0, # 0
  then
  mov s r2, tos
  rsb pl tos, tos, # 0
  b eq 1 $
  bl division
  teq r0, # 0
  0<> if
    eor s r3, r3, r2
      rsb mi tos, tos, # 0
      rsb mi r0, r0, # 0
    cmp r2, # 0
      rsb mi r0, r0, # 0
  else
    eor s r3, r3, r2
    rsb mi tos, tos, # 0
  then
  stmfd sp !, { r0 }
  next
1 $:
  mvn tos, # 0
  stmfd sp !, { tos }
next c;

code fm/mod
  ldmfd sp !, { r0, r1 }
  mov s r3, r0
  0< if
    rsb s r1, r1, # 0
    rsc r0, r0, # 0
  then
  mov s r2, tos
  rsb pl tos, tos, # 0
  b eq 1 $
  bl division
  teq r0, # 0
  0<> if
    cmp r2, # 0
      rsb mi r0, r0, # 0
    eor s r3, r3, r2
      rsb mi tos, tos, # 0
      sub mi r0, r2, r0
      sub mi tos, tos, # 1
  else
    eor s r3, r3, r2
    rsb mi tos, tos, # 0
  then
  stmfd sp !, { r0 }
  next
1 $:
  mvn tos, # 0
  stmfd sp !, { tos }
next c;

: /mod
    >r s>d r> fm/mod ;

: /
    /mod nip ;

: mod          ( n1 n2 -- rem )
    /mod drop ;

: */mod        ( n1 n2 n3 -- rem quot )
    >r m* r> fm/mod ;

: */           ( n1 n2 n3 -- quot )
    */mod nip ;

: mu/mod       ( ud u -- rem dquot )
    >r 0  r@  um/mod  r>  swap  >r um/mod r> ;

: ad>of ( to from -- off )
    8 + - 2 rshift &ffffff and ;



create pocket         260 allot
create cur-file       260 allot
create temp$          260 allot

12 constant #vocs

create context        #vocs cells allot

variable current
variable last
variable voc-link
0 value source-id
  create filebuf        260 allot
  create tib            260 allot
  create (source)   here 0 , tib ,
constant #tib
variable >in
variable state
variable warning       -1 warning !-t
variable caps          -1 caps !-t

code source
  adr r2, (source)
  ldmfd r2, { r0, r1 }
  stmfd sp !, { r1, tos }
  mov tos, r0
next c;

labcreate dovoc
  bic link, link, # &fc000003
  add link, link, # 8
  str link, context
next c;


: pad
    here 260 + ;

code count     ( ad -- ad+1 cnt )
  add tos, tos, # 1
  stmfd sp !, { tos }
  ldrb tos, [ tos, # -1 ]
next c;

code wcount    ( ad -- ad+2 cnt )
  add r0, tos, # 2
  stmfd sp !, { r0 }
  ldrb tos, [ r0, # -2 ]
  ldrb r0, [ r0, # -1 ]
  add tos, tos, r0, lsl # 8
next c;

code lcount    ( ad -- ad+4 cnt )
  add tos, tos, # 4
  stmfd sp !, { tos }
  ldr tos, [ tos, # -4 ]
next c;

code zcount    ( ad -- ad len )
  stmfd sp !, { tos }
  bic r0, tos, # 3
  ldr r1, [ r0 ]
  mov r2, # 1
  orr r2, r2, # &100
  orr s r2, r2, r2, asl # 16
  sbc s r3, tos, r0
  orr gt r1, r1, r3, asl # 15
  orr gt r1, r1, r3, asl # 14
  orr pl r1, r1, # &ff
1 $:
  sub s r3, r1, r2
  eor cs r3, r3, r1
  bic cs s r3, r2, r3
  ldr eq r1, [ r0, # 4 ]!
  b eq 1 $
  tst r1, # &ff
  add ne r0, r0, # 1
  tst ne r1, # &ff00
  add ne r0, r0, # 1
  tst ne r1, # &ff0000
  add ne r0, r0, # 1
  sub tos, r0, tos
next c;

\ : place
\     swap 255 min 0max swap 2dup c! 1+ swap move ;

code place     ( from cnt to -- ) \ Move "cnt" characters from "from" to "to" + 1
                                  \ with preceeding count byte at "to".
  mov r3, tos
  ldmfd sp !, { r0, r1, tos }
  strb r0, [ r3 ], # 1
  orr s r0, r0, r0
  next eq
  begin
    ldrb r2, [ r1 ], # 1
    strb r2, [ r3 ], # 1
    sub s r0, r0, # 1
  0= until
next c;

\ : place+
\     >r 255 min 0max 255 r@ c@ - min r> 2dup 2>r
\     count + swap move 2r> c+! ;

code +place     ( from cnt to -- ) \ append text to counted string
  mov r3, tos
  ldrb r4, [ r3 ]
  ldmfd sp !, { r0, r1, tos }
  add r2, r4, r0
  strb r2, [ r3 ], # 1
  add r3, r3, r4
  orr s r0, r0, r0
  next eq
  begin
    ldrb r2, [ r1 ], # 1
    strb r2, [ r3 ], # 1
    sub s r0, r0, # 1
  0= until
next c;

\ store zero terminated text in memory
code z!  ( to from  -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  begin
   ldrb r3, [ r1 ], # 1
   strb r3, [ r0 ], # 1
   teq r3, # 0
  0= until
next c;

code -trailing ( ad len -- ad len' )
  ldr r0, [ sp ]
  begin
    sub s tos, tos, # 1
  b cc 1 $
    ldrb r1, [ r0, tos ]
    teq r1, # 32
  0<> until
1 $: add tos, tos, # 1
next c;

code -nulls    ( ad len -- ad len' )
  ldr r0, [ sp ]
  begin
    sub s tos, tos, # 1
  b cc 1 $
    ldrb r1, [ r0, tos ]
    teq r1, # 0
  0<> until
1 $: add tos, tos, # 1
next c;

code /string   ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  cmp tos, # 0
  0>= if
    cmp r0, tos
    mov ls tos, r0
  then
  add r1, r1, tos
  sub tos, r0, tos
  stmfd sp !, { r1 }
next c;

code upc       ( c -- c' )
  tst tos, # 64
  next eq
  cmp tos, # 192
  bic cs tos, tos, # 32
  next cs
  cmp tos, # ascii {
  bic cc tos, tos, # 32
next c;

code upper     ( ad len -- )
  mov r0, tos
  ldmfd sp !, { r1, tos }
  begin
    ldrb r3, [ r1 ]
    tst r3, # 64
    b eq 1 $
    cmp r3, # 192
    bic cs r3, r3, # 32
    b cs 1 $
    cmp r3, # ascii {
    bic cc r3, r3, # 32
1 $:
    strb r3, [ r1 ], # 1
    sub s r0, r0, # 1
  0= until
next c;

code ?uppercase ( ad -- ad )
  adr r0, caps
  ldr r0, [ r0 ]
  teq r0, # 0
  next eq
  mov r1, tos
  ldrb r0, [ r1 ], # 1
  teq r0, # 0
  0<> if
    begin
      ldrb r3, [ r1 ]
      tst r3, # 64
      b eq 1 $
      cmp r3, # 192
      bic cs r3, r3, # 32
      b cs 1 $
      cmp r3, # ascii {
      bic cc r3, r3, # 32
1 $:
      strb r3, [ r1 ], # 1
      sub s r0, r0, # 1
    0= until
  then
next c;

defer outpause ' noop is outpause

code OS_WriteC  ( c -- )
  mov r0, tos
  swi " OS_WriteC"
  ldmfd sp !, { tos }
next c;

variable #out

: _emit
    OS_WriteC outpause 1 #out +! ;

defer emit ' _emit is emit

code %_key?   ( -- f )
  stmfd sp !, { tos }
  mov r0, # &c6
  mov r1, # 0
  mov r2, # &ff
  swi " OS_Byte"
  teq r1, # 0
  0= if \ not execing from file.
    mov r0, # &b1 \ input device
    mov r2, # &ff
    swi " OS_Byte"
    rsb r1, r1, # &ff
    mov r0, # &80
    swi " OS_Byte"
    add tos, r1, r2, lsl # 8
    next
  then
  mov r0, # 5
  swi " OS_Args"
  sub s tos, r2, # 1
  sbc tos, tos, tos
next c;

: _key? pause  %_key? ;

defer key? ' _key? is key?

code %_key     ( -- c )
  stmfd sp !, { tos }
  swi " OS_ReadC"
  mov tos, r0
  next cc
  cmp r0, # 27
  next ne
  mov r0, # 126
  swi " OS_Byte"
next c;

: _key
    begin key? until
    %_key ;
defer key  ' _key is key

: _beep
    7 emit ;
defer beep   ' _beep is beep

0 value accept-cnt   \ current count of chars accepted

: _accept      ( a1 n1 -- n2 )
    0 swap 0
    ?do     drop
      i to accept-cnt \ save in case we need it
      key
      case
        8 of i 1 <           \ if input is empty
             if 0            \ do nothing but
               beep          \ beep at user
             else 1-         \ decrement address 1
               -1 8 emit bl emit 8 emit
             then                            endof
       27 of dup c@ emit 1+ 1                endof
       13 of i leave                         endof
             dup emit
             2dup swap c!    \ place the character
             swap 1+ swap    \ bump the address
             1 swap          \ loop increment
      endcase
      i 1+ swap       \ in case loop completes
   +loop nip ;

defer accept ' _accept is accept

code OS_WriteN
  mov r1, tos
  ldmfd sp !, { r0, tos }
  swi " OS_WriteN"
next c;

: _type
    0max dup #out +! OS_WriteN outpause ;
defer type ' _type is type

code os_newline ( -- )
  swi " OS_NewLine"
next c;

: _cr
    OS_NewLine #out off ;
defer cr   ' _cr is cr

: _cls #out off ;
defer cls  ' _cls is cls

: _?cr ( n -- ) #out @ + ( lmargin ) 50 > if cr then ;
defer ?cr  ' _?cr is ?cr

code os_exit
  mov r0, tos
  ldmfd sp !, { r1, r2 }
  swi " OS_Exit"
next c;

: _bye
    ."  Leaving.." cr
    0 &58454241 0 os_exit ;
defer bye  ' _bye is bye

: _console ;
defer console ' _console is console

&c0 constant r/w
&40 constant r/o
: bin ;

code OS_Find ( fileid/name reason -- handle | false )
  ldmfd sp !, { r1 }
  mov r0, tos
  swi x " OS_Find"
  mov vs tos, # 0
  mov vc tos, r0
next c;

: open-file   ( ad len fam -- fileid ior )
    >r over + 0 swap c! r> OS_Find dup 0= ;

: close-file  ( fileid -- ior )
    0 OS_Find ;

code read-file   ( ad len fileid -- bytesread ior )
  ldmfd sp !, { r1, r2 }
  mov r3, r1
  mov r5, r1
  mov r1, tos
  mov r0, # 4
  swi x " OS_GBPB"
  mov vc tos, # 0
  mvn vs tos, # 0
  sub r5, r5, r3
  stmfd sp !, { r5 }
next c;

code create-file ( ad len fam -- fileid ior )
  ldmfd sp !, { r0, r1 }
  mov r2, # 0
  strb r2, [ r0, r1 ]
  mov r0, # &83
  swi x " OS_Find"
  mov vc tos, # 0
  mvn vs tos, # 0
  stmfd sp !, { r0 }
next c;

code delete-file ( ad len -- ior )
  mov r0, # 6
  ldmfd sp !, { r1 }
  mov r2, # 0
  strb r2, [ r1, tos ]
  swi x " OS_File"
  mov vc tos, # 0
  mvn vs tos, # 0
next c;

code write-file ( ad len fileid -- ior )
  mov r0, # 2
  mov r1, tos
  ldmfd sp !, { r3, tos }
  mov r2, tos
  swi x " OS_GBPB"
  mov vc tos, # 0
  mvn vs tos, # 0
next c;

: write-line ( ad len fileid -- ior )
    dup>r write-file 10 sp@ 1 r> write-file nip or ;

16384 value iblen               \ current input buffer length
16384 value ibfull              \ full buffer size, used to restore IBLEN
    0 value inbuf               \ input buffer address
    0 value instart
    0 value inlength
    0 value outbuf
    0 value outlen
    0 value cur-handle

: _readl
    inlength 0> 0=
    if inbuf ibfull cur-handle read-file
      if r>drop 0 -1 exit then
      dup to iblen to inlength
      inbuf to instart
    then
    instart inlength 2dup &0a scan dup>r
    nip - outlen umin tuck outbuf swap cmove
    dup 1+ dup +to instart negate +to inlength
    dup +to outbuf dup negate +to outlen r> ;

: read-line ( ad len fileid -- len flag ior )
    to cur-handle to outlen to outbuf
    inlength 0> 0= iblen ibfull < and
    if 0 0 0 exit then
    _readl
    iblen ibfull < or 0=
    if _readl drop + then
    true 0 ;

code OS_File
  mov r0, tos
  ldmfd sp !, { r1, r2, r3, r4, r5, tos }
  swi x " OS_File"
next c;

: save-file   ( ad len filename -- )
    1+ >r
    bounds 0 &ff8 r>
    10 OS_File ;

: _getxy #out @ 0 ;

: _getcolrow  60 0
;

: tone 2drop
;

: beep! 2drop
;

code digit     ( c base -- n f )
  ldr r0, [ sp ]
  sub s r0, r0, # 48
  u>= if
    cmp r0, # 10
    b cc 1 $
    cmp r0, # 17
    u>= if
      sub r0, r0, # 7
1 $:  cmp r0, tos
      u< if
        str r0, [ sp ]
        mvn tos, # 0
        next
      then
    then
  then
  mov tos, # 0
next c;

code >number   ( ud ad len -- ud ad len )
  teq tos, # 0
  0<> if
    ldmfd sp !, { r0, r1, r2 } \ ad hi lo
    adr r3, base
    ldr r3, [ r3 ]
    begin
      ldrb r4, [ r0 ], # 1
      sub s r4, r4, # 48
      b cc 1 $
      cmp r4, # 9
      > if
        sub r4, r4, # 7
        cmp r4, # 10
        b cc 1 $
      then
      cmp r4, r3
      b ge 1 $
      mov r5, r2, lsl # 16
      mov r5, r5, lsr # 16
      mla r4, r5, r3, r4     \ lolo * base + digit
      mov r2, r2, lsr # 16
      mul r5, r2, r3         \ hilo * base
      mul r2, r1, r3         \ hi   * base
      add r5, r5, r4, lsr # 16
      add r1, r2, r5, lsr # 16
      mov r4, r4, lsl # 16
      mov r4, r4, lsr # 16
      add r2, r4, r5, lsl # 16
      sub s tos, tos, # 1
    0= until
1 $: sub r0, r0, # 1
    stmfd sp !, { r0, r1, r2 }
  then
next c;

0 value double?
-1 value dp-location

: _number?
    false to double?                \ initially not a double #
    -1 to dp-location
    over c@ [char] - = over and dup>r
    if      1 /string
    then    0 0 2swap >number
    over c@ [char] . =               \ next char is a '.'
    if      dup 1- to dp-location
            1 /string >number
            true to double?         \ mark as a double number
    then    nip 0=
    r>
    if      >r dnegate r>
    then    ;

: ?missing    ( f -- )
    abort" is undefined" ;

: (number)    ( ad -- d )
    count _number? 0= ?missing ;

defer number    ' (number) is number

: space
    bl emit ;

128 constant spcs-max

create spcs &20202020
dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t
dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t
dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t
dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t dup ,-t     ,-t

: spaces     ( n -- )
    begin dup 0>
    while dup spcs-max min spcs over type -
    repeat drop ;

: _gotoxy drop
    #out @ - dup 0> if dup spaces then drop ;

: hex       16 base ! ;
: decimal   10 base ! ;
: binary     2 base ! ;
: octal      8 base ! ;

code hold    ( c -- )
  adr r0, hld
  ldr r1, [ r0 ]
  strb tos, [ r1, # -1 ]!
  str r1, [ r0 ]
  ldmfd sp !, { tos }
next c;

: <#
    pad hld ! ;

: #>
    2drop hld @ pad over - ;

: sign
    0< if [char] - hold then ;

: #            ( d -- d' )
    base @ mu/mod rot 9 over <
    if 7 + then [char] 0 + hold ;

: #s           ( d -- 0 0 )
    begin # 2dup or 0= until ;

: (d.)         ( d -- ad len )
    tuck dabs <# #s rot sign #> ;

: d.           ( d -- )
    (d.) type space ;

: d.r          ( d len -- )
    >r (d.) r> over - spaces type ;

: .     s>d d. ;
: .r    >r s>d r> d.r ;
: u.    0 d. ;
: u.r   0 swap d.r ;
: h.    base @ swap hex u. base ! ;
: ?     @ . ;

code word     ( char -- ad )
  adr r0, (source)
  ldmfd r0, { r1, r4 }
  adr r0, >in
  ldr r3, [ r0 ]  \ r0= >in
  add r2, r4, r3
  sub s r1, r1, r3
  mov le r1, # 0
  > if
    cmp tos, # 32
    0= if
      begin
        ldrb r5, [ r2 ], # 1
        cmp r5, tos
      <= while
        sub s r1, r1, # 1
      0= until
        mov r6, r2
        mov r5, r6
        b 1 $
      then
      sub r6, r2, # 1    \ r6= start of word
      add tos, tos, # 1
      begin
        sub s r1, r1, # 1
      0<> while
        ldrb r5, [ r2 ], # 1
        cmp r5, tos
      u< until
        sub s r5, r2, # 1    \ r5= end of word
      then
      mov eq r5, r2
    else
      begin
        ldrb r5, [ r2 ], # 1
        cmp r5, tos
      0= while
        sub s r1, r1, # 1
      0= until
        mov r6, r2
        mov r5, r6
        b 1 $
      then
      sub r6, r2, # 1    \ r6= start of word
      begin
        sub s r1, r1, # 1
      0<> while
        ldrb r5, [ r2 ], # 1
        cmp r5, tos
      0= until
        sub s r5, r2, # 1    \ r5= end of word
      then
      mov eq r5, r2
    then
1 $:
    sub r1, r2, r4       \ update >in
    str r1, [ r0 ]
    sub r1, r5, r6
    cmp r1, # 255
    mov gt r1, # 255
  then
  adr r0, pocket         \ r1= count
  mov tos, r0
  strb r1, [ r0 ], # 1
  teq r1, # 0
  0<> if
    begin
      ldrb r5, [ r6 ], # 1
      strb r5, [ r0 ], # 1
      sub s r1, r1, # 1
    0= until
  then
  strb r1, [ r0 ]
next c;

code skip      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldrb r2, [ r1 ], # 1
      cmp r2, tos
      b ne 1 $
      sub s r0, r0, # 1
    0= until
    add r1, r1, # 1
1 $:
    sub r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code scan      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldrb r2, [ r1 ], # 1
      cmp r2, tos
      b eq 1 $
      sub s r0, r0, # 1
    0= until
    add r1, r1, # 1
1 $:
    sub r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code wskip c;
code wscan c;

code lskip      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldr r2, [ r1 ], # 1
      cmp r2, tos
      b ne 1 $
      sub s r0, r0, # 1
    0= until
    add r1, r1, # 1
1 $:
    sub r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code lscan      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldr r2, [ r1 ], # 1
      cmp r2, tos
      b eq 1 $
      sub s r0, r0, # 1
    0= until
    add r1, r1, # 1
1 $:
    sub r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code -skip      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldrb r2, [ r1 ], # -1
      cmp r2, tos
      b ne 1 $
      sub s r0, r0, # 1
    0= until
    sub r1, r1, # 1
1 $:
    add r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code -scan      ( ad len c -- ad' len' )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  0<> if
    begin
      ldrb r2, [ r1 ], # -1
      cmp r2, tos
      b eq 1 $
      sub s r0, r0, # 1
    0= until
    sub r1, r1, # 1
1 $:
    add r1, r1, # 1
  then
  mov tos, r0
  stmfd sp !, { r1 }
next c;

code compare   ( ad1 len1 ad2 len2 -- -1 | 0 | 1 )
  ldmfd sp !, { r1, r2, r3 }
  cmp r2, tos
    mov cc tos, r2
  begin
    ldrb r2, [ r1 ], # 1
    ldrb r4, [ r3 ], # 1
    cmp r2, r4
    b ne 1 $
    sub s tos, tos, # 1
  0= until
  next
1 $:
  mov lt tos, # 1
  mvn gt tos, # 0
next c;

CODE SEARCH     ( ad1 len1 ad2 len2 -- ad3 len3 flag )
  ldmfd sp !, { r0, r1, r2 }
  sub sp, sp, # 8
  teq tos, # 0
  mvn eq tos, # 0
  next eq
1 $:
    cmp r1, tos
  b lt 2 $
    mov r3, # 0
3 $:
    ldrb r4, [ r2, r3 ]
    ldrb r5, [ r0, r3 ]
    cmp r5, r4
    add ne r2, r2, # 1
    sub ne r1, r1, # 1
  b ne 1 $
    add r3, r3, # 1
    cmp r3, tos
  b ne 3 $
    stmfd sp, { r1, r2 }
    mvn tos, # 0
  next
2 $:
  mov tos, # 0
next c;

: parse       ( char -- ad len )
    >r source >in @ /string
    2dup r> scan nip -
    dup 1+ >in +! ;

: .(
    [char] ) parse type ; immediate

: \
    source >in ! drop ; immediate

: >body
    cell+ ;

: body>
    cell- ;

: l>name
    5 - ;

: n>link
    5 + ;

: >name
    9 - ;

: name>
    9 + ;

: >view
    8 - ;

: view>
    8 + ;

  1 value    #threads
512 constant maxthreads
 31 constant name-max-chars

: vlink>voc     ( voc-link-field -- voc-address )
    cell+ ;

: voc>vlink     ( voc-address -- voc-link-field )
    cell - ;

: voc#threads   ( voc-address -- #threads )
    2 cells - @ ;

: vcfa>voc      ( vocabulary-cfa -- voc-address )
    >body 2 cells+ ;

: voc>vcfa      ( voc-address -- vocabulary-cfa )
    2 cells - body> ;


code "#hash     ( a1 n1 #threads -- n2 )
  ldmfd sp !, { r0, r1 }
  mov r3, # 0
  begin
    ldrb r2, [ r1 ], # 1
    eor r3, r2, r3, lsl # 1
    sub s r0, r0, # 1
  0= until
  sub tos, tos, # 1
  and tos, tos, r3
  mov tos, tos, lsl # 2
next c;

code nfa-count        ( ad -- ad' len )
  ldrb r0, [ tos ]
  and r0, r0, # 63
  sub tos, tos, r0
  stmfd sp !, { tos }
  mov tos, r0
next c;

code search-1wordlist ( ad len wid -- 0 | cfa f )
  ldmfd sp !, { r0, r1 }
  teq r0, # 0
  mov eq tos, # 0
  begin
    begin
      ldr ne tos, [ tos ]
      teq ne tos, # 0
      next eq
      ldrb r3, [ tos, # -5 ]
      and r3, r3, # 31
      cmp r3, r0
    0= until
    sub r2, tos, # 5
    sub r2, r2, r3
    begin
      sub s r3, r3, # 1
    u>= while
      ldrb r4, [ r2, r3 ]
      ldrb r5, [ r1, r3 ]
      cmp r4, r5
    0<> until                  2swap
  again
    then
  add r2, tos, # 4
  stmfd sp !, { r2 }
  ldrb r3, [ tos, # -5 ]
  and s r3, r3, # &80
  mov ne tos, # 1
  mvn eq tos, # 0
next c;

: search-wordlist      ( addr len wid -- 0 | cfa flag )
    >r 2dup r@ voc#threads "#hash r> + search-1wordlist ;

: (find)       ( string -- string FALSE | cfa flag )
    dup c@ 0= if 0 exit then
    context
    begin   dup @                   \ while not at end of list
    while   dup 2@ <>               \ and not the same vocabulary
                                    \ as NEXT time
      if over count name-max-chars min
        2 pick @ search-wordlist ?dup
        if      2swap 2drop EXIT then    \ found it, so we're done searching
      then  cell+                   \ step to next vocabulary
    repeat  drop
    FALSE  ;

defer find        ' (find) is find

: defined
    bl word ?uppercase find ;

: immediate
    last @ 128 toggle ;

: hide
    last @ n>link @
    current @
    last @ nfa-count
    current @ 2 cells- @
    "#hash + ! ;

: reveal
    last @ n>link
    current @
    last @ nfa-count
    current @ 2 cells- @
    "#hash + !
    synccode ;

: literal
    compile lit , ; immediate

: char
    bl word 1+ c@ ;

: [char]
    char [compile] literal ; immediate

: '
    defined 0= ?missing ;

: [']
    ' [compile] literal ; immediate

: [compile]
    ' compile, ; immediate

: postpone
    defined dup 0= ?missing
    0< if compile compile then
    compile, ; immediate

defer \n->crlf     ' 2drop is \n->crlf

: ,"
    [char] " parse here align >r dup c,
    dup allot r@ 1+ swap move 0 c, align r> count \n->crlf ;


: ,'
    [char] ' parse here align >r dup c,
    dup allot r@ 1+ swap move 0 c, align r> count \n->crlf ;

code (("))        ( -- c-string )
  stmfd sp !, { tos }
  ldmfd rp !, { tos }
  mov r0, tos
  ldrb r1, [ r0 ], # 5
  add r0, r1, r0
  bic r0, r0, # 3
  stmfd rp !, { r0 }
next c;

: (c")
    ((")) ;

: c"
    compile (c") ," ; immediate

: (s")
    ((")) count ;

: s"
        state @
        if      compile (s")  ,"
        else    [char] " word
                temp$ over c@ 1+ move
                temp$ count
        then ; immediate

: (.")
    ((")) count type ;

: ."
    compile (.") ," ; immediate

: catch       ( cfa -- flag )
    sp@ >r
    lp @ >r
    handler @ >r
    rp@ handler !
    execute
    r> handler !
    r> r> 2drop 0 ;

: throw        ( n -- )
    ?dup
    if handler @ rp!
      r> handler !
      r> lp !
      r> swap >r sp! drop
      r>
    then ;

: abort
    -1 throw ;

: (abort")
    ((")) swap
    if msg !
      -2 throw
    then drop ;

: abort"
    compile (abort") ," ; immediate

: ?exec
    state @ abort" execution only" ;

: ?comp
    state @ 0= abort" compilation only" ;

: ?pairs
    xor abort" conditionals not paired" ;

: >mark
    here 0 , ;

: >resolve
    here swap ! ;

: <mark
    here ;

: <resolve
    , ;

: ahead
    >mark 2 ; immediate

: if
    ?comp compile ?branch >mark 2 ; immediate

: else
    ?comp 2 ?pairs compile branch >mark
    swap >resolve 2 ; immediate

: then
    ?comp 2 ?pairs compile _then >resolve ; immediate

: endif
    ?comp 2 ?pairs >resolve ; immediate

: begin
    compile _begin
    ?comp <mark 1 ; immediate

: until
    ?comp 1 ?pairs
    compile _until <resolve ; immediate

: again
    ?comp 1 ?pairs
    compile _again <resolve ; immediate

: while
    ?comp
    compile _while >mark 2
    2swap ; immediate

: repeat
    ?comp
    1 ?pairs
    compile _repeat <resolve
    2 ?pairs >resolve ; immediate

: do
    ?comp
    compile (do) >mark 3 ; immediate

: ?do
    ?comp
    compile (?do) >mark 3 ; immediate

: loop
    ?comp
    3 ?pairs
    compile (loop) dup cell+ <resolve
    >resolve ; immediate

: +loop
    ?comp
    3 ?pairs
    compile (+loop) dup cell+ <resolve
    >resolve ; immediate

: case
    compile _case
    ?comp 0 ; immediate

: of
    ?comp
    compile _of >mark 4 ; immediate

: endof
    ?comp
    4 ?pairs
    compile _endof >mark
    swap >resolve 5 ; immediate

: endcase
    ?comp
    compile _endcase
    begin ?dup
    while 5 ?pairs >resolve
    repeat ; immediate

: link,
    align here over @ , swap ! ;

: call! ( to from -- )
    dup>r ad>of &eb000000 or r> ! ;

: call,
    here cell allot call! ;

variable loadline
variable ?loading

: "name,        ( a1 n1 -- )    \ align and compile name a1,n1 at here
    name-max-chars min align
    dup 0= abort" Need a NAME to create!"
    2>r
    caps @
    if      2r@ upper
    then    3 2r@ nip 3 and - allot \ pre-align for name length
    2r@ current @ search-wordlist
    if      warning @
            if      cr ?loading @
                    if      ." From file: " cur-file count type
                            ."  word: "
                    then    2r@ type ."  isn't unique "
            then    drop
    then    2r> >r here r@ move r@ allot here last ! r> c, ;

: view,         ( -- )          \ compile the view field
    ?loading @
    if      loadline @ ,  else    -1 ,  then    ;

: _"header      ( a1 n1 -- )    \ build a hashed header from a1,n1
    name-max-chars min 2dup 2>r "name, view,
    current @ dup  2r> rot voc#threads "#hash + link, ;

defer "header   ' _"header is "header

: memory-total
    [ memtotal ] literal @ ;

: ?memchk       ( n1 -- )       \ test to see if we have enough memory
    here +  memory-total ibfull - 512 -  U> abort" Out of memory!" ;

: _header       ( -<name>- )    \ build a header, but check available memory
    2000 ?memchk
    bl word count "header ;

defer header        ' _header is header

: create
    header dovar call, ;

variable csp

: !csp
    sp@ csp ! ;

: ?csp
    sp@ csp @ xor abort" stack changed" ;

: (;code)
    r> last @ name> call! ;


: does>         ( -- )
    compile (;code)
    &e3ce03ff , \ bic r0, link, # &fc000003
    dodoes here ad>of
    &eb000000 or , synccode ; immediate

: ]
    state on ;

: [
    state off ; immediate

: _:
    header hide !csp docol call, ] ;

: :noname
    align here !csp docol call, ] ;

defer :           ' _: is :

: ;
    ?comp ?csp
    reveal compile unnest [compile] [ ; immediate

: recurse
    ?comp last @ name> compile, ; immediate

: constant
    header docon call, , ;

: variable
    create 0 , ;

: defer
    header &e51ff004 , compile noop
    here defer-list @ , defer-list ! compile noop ;

: definitions
    context @ current ! ;

defer boot  ' noop is boot

: 2constant
    create , , ;code also assembler
    bic link, link, # &fc000003
    ldmfd link, { r0, r1 }
    stmfd sp !, { r1, tos }
    mov tos, r0
    next c; previous drop

: 2variable
    variable 0 , ;

code @(ip)
  stmfd sp !, { tos }
  ldr r0, [ rp ]
  ldr tos, [ r0 ], # 4
  str r0, [ rp ]
next c;

code >is
  add tos, tos, # 4
next c;

: (is)
    @(ip) >is ! ;

: is
    state @
    if compile (is) ' compile,
    else ' >is !
    then ; immediate

: value
    header
    dovalue call,  ,  dovalue! call,  dovalue+! call, ;

: to
    ' cell+ cell+
    state @
    if , exit
    then execute ; immediate

: +to
    ' cell+ cell+ cell+
    state @
    if , exit
    then execute ; immediate

: &of
    ' cell+
    state @
    if compile lit , then ; immediate

: query
    0 to source-id tib dup 256 accept
    (source) 2!
    >in off ;

: ?stack
    depth 0< abort" stack underflow" ;

: _number,
    double? 0=
    if drop then
    state @
    if double? 0=
      if [compile] literal
      else swap [compile] literal [compile] literal
      then
    then ;

defer number,
' _number, is number,

defer cursor-off
 ' noop is  cursor-off

defer cursor-on
 ' noop is  cursor-on

: _interpret
    cursor-off
    begin
      bl word dup c@
    while
      ?uppercase find ?dup
      if state @ =
        if compile,  else execute ?stack synccode then
      else number number,
      then
    repeat drop ;

defer interpret
' _interpret is interpret

: evaluate
    source 2>r >in @ >r source-id >r
    (source) 2! >in off
    -1 to source-id
    interpret
    r> to source-id
    r> >in ! 2r> (source) 2! ;

: wait
    key 27 =
    if ." ok" abort cursor-on then ;

: start/stop
    key? if wait wait then ;

: refill
    source-id ?dup
    if 1+
      if 1 loadline +!
        tib dup 260
        source-id read-line abort" read error"
        if (source) 2! >in off true exit then
        2drop
      then false exit
    then cr query true ;

: linkfile
    ?loading @
    if loadfile link,
      count here place
      here c@ 2 + aligned allot
    else drop
    then ;

variable echo
defer stack-check    ' noop is stack-check
variable start-line

: >line
    1- 0max ?dup
    if 0 do refill drop loop
    then ;

: (fload)
    start-line @ >line start-line off
    begin refill
    while echo @
      if cr source type start/stop then
      interpret stack-check
    repeat ;

create openbuf 260 allot

: _"open
    2dup 2>r openbuf place
    openbuf count r/o open-file dup 0=
    ?loading @ 0= or
    if 2r@ cur-file place then
    2r> pocket place ;

defer "open      ' _"open is "open

: $open
    count "open ;

code file-position ( fileid -- ud ior )
  mov r0, # 0
  mov r1, tos
  swi x " OS_Args"
  mov vc tos, # 0
  mvn vs tos, # 0
  stmfd sp !, { r0, r2 }
next c;

code reposition-file ( ud fileid -- ior )
  mov r1, tos
  ldmfd sp !, { r0, r2 }
  mov r0, # 1
  swi x " OS_Args"
  mov vc tos, # 0
  mvn vs tos, # 0
next c;

code file-size ( fileid -- ud ior )
  mov r0, # 2
  mov r1, tos
  swi x " OS_Args"
  mov vc tos, # 0
  mvn vs tos, # 0
  mov r0, # 0
  stmfd sp !, { r0, r2 }
next c;

code resize-file ( ud fileid -- ior )
  mov r1, tos
  ldmfd sp !, { r0, r2 }
  mov r0, # 3
  swi x " OS_Args"
  mov vc tos, # 0
  mvn vs tos, # 0
next c;

: include-file
    loadfile @ cell+ >r                 ?loading @ >r
    loadline @ >r                       >in @ >r
    source-id dup>r swap                to source-id
    source 2>r                          filebuf 0 (source) 2!
    ?loading on                         pocket ?uppercase linkfile
    loadline off
    dup 0>
    if dup file-position 2drop inlength -
      0 rot reposition-file drop
    else drop
    then
    ibfull to iblen  0 to inlength
    ['] (fload) catch
    source-id close-file drop
    ibfull to iblen  0 to inlength
    2r> (source) 2!                     r> to source-id
    throw
    r> >in !                            r> loadline !
    r> ?loading !                       align
    r> linkfile
    ?loading @
    if loadfile @ cell+
      count 255 min cur-file place
      source nip >in !
    then ;

: included
    "open abort" file not found"
    include-file ;

: fload
    bl word count included ;

: include
    bl word count included ;

: ok
    cur-file count included ;

: ((
    begin bl word dup @ &ffffff and
      &292902 <>
    while c@ 0=
      if refill 0= abort" missing ))" then
    repeat drop ; immediate

: \s
    2r> 2drop [compile] \ ; immediate

defer edit-error  ' noop is edit-error

: _reset-stacks
    sp0 @ sp! ;

defer reset-stacks  ' _reset-stacks is reset-stacks

: _message
    base @ >r decimal cr ." Error: "
    pocket count type space
    dup -2 =
    if drop msg @ count type
    else ." Error #" .
    then ?loading @
    if cr ." File: " loadfile @ cell+ count type
      ."  at line: " loadline ?
      edit-error
    then r> base ! ;

defer message       ' _message is message

variable .smax      8 .smax !-t

: .s
    ?stack depth .smax @ min dup
    if ." [" depth 1- 1 .r ." ] "
      begin dup pick 1 .r base @ 16 =
        if ." h" then
        space 1- dup 0=
      until
    else ."  empty "
    then drop ;

: query-interpret
    query space interpret ;

: quit  ( -- )
    rp0 @ rp!
    begin   [compile] [
      ?loading off
      begin   cr ['] query-interpret catch  ?dup 0=
      while   state @ 0=
        if      ."  ok"  depth .smax @ min 0
          ?do  [char] . emit loop
        then  cursor-on
      repeat
      dup 1+  ( no message on abort )
      if  console message  then
      reset-stacks
      cursor-on
    again ;


: docmdtail
    [ commline ] literal @
    255 bl scan 2dup 0 scan nip - drop drop  ;


defer commandline    ' docmdtail is commandline


: cold
    ['] boot catch 0=
    if ['] commandline catch ?dup
      if dup 1+
        if message then
        sp0 @ sp!
      then quit
    then bye ;

code largest    ( a1 n1 --- a2 n2 )
  ldr r0, [ sp ]
  mov r1, # 0
  mov r2, r0
  begin
    ldr r3, [ r0 ], # 4
    cmp r3, r1
      sub hi r2, r0, # 4
      mov hi r1, r3
    sub s tos, tos, # 1
  u<= until
  str r2, [ sp ]
  mov tos, r1
next c;

\ : dump          ( ad len -- )
\     base @ >r hex
\     0 do   cr dup 6 .r space  16 0 do   dup c@ 3 .r 1+   loop
\     16 +loop   drop  r> base ! ;

code op@
  stmfd sp !, { tos }
  mov tos, op
next c;

code op!
  mov op, tos
  ldmfd sp !, { tos }
next c;

code +ov? ( n1 n2 -- f )
  ldmfd sp !, { r0 }
  add s r0, r0, tos
  mov tos, # 0
  sub vs tos, tos, # 1
next c;

code Wimp_CreateMenu
  mov r1, tos
  ldmfd sp !, { r2, r3, tos }
  swi " Wimp_CreateMenu"
next c;

code Wimp_SlotSize ( next cur -- free next cur )
  mov r0, tos
  ldmfd sp !, { r1 }
  swi " Wimp_SlotSize"
  stmfd sp !, { r1, r2 }
  mov tos, r0
next c;

code OS_Heap ( misc ^blk ^heap reason -- r3 r2 f )
  mov r0, tos
  ldmfd sp !, { r1, r2, r3 }
  swi x " OS_Heap"
  mvn vs tos, # 0
  mov vc tos, # 0
  stmfd sp !, { r2, r3 }
next c;

code vsync
  mov r0, # 19
  swi " OS_Byte"
next c;

code OS_CLI ( ad -- f )
  mov r0, tos
  swi x " OS_CLI"
  mov vs tos, # 0
  mvn vc tos, # 0
next c;


0 local l0
1 local l1
2 local l2
3 local l3
4 local l4
5 local l5
6 local l6
7 local l7

: .id ( nfa -- )
    nfa-count type space ;

init-assembler
here &8000 ad>of &ea000000 or coldstart !-t
  swi " OS_GetEnv"
  adr r2, memtotal
  str r1, [ r2 ]
  adr r2, commline
  str r0, [ r2 ]
  adr r0, filebuff
  ldr r2, [ r0 ]
  adr r0, ' ibfull >body-t
  str r2, [ r0 ]
  sub rp, r1, r2                \ rp=RAM limit
  adr r0, ' inbuf >body-t
  str rp, [ r0 ]
  adr r0, rp0
  str rp, [ r0 ]
  adr r2, retstack
  ldr r2, [ r2 ]
  sub sp, rp, r2
  adr r0, sp0
  str sp, [ r0 ]
  add sp, sp, # 4
  mov tos, # 0
  mov r0, # 10                  \ set base to decimal
  adr r1, base
  str r0, [ r1 ]
  b ' cold a;                   \ goto cold colon definition

2048 retstack !-t
2048 datstack !-t
16384 filebuff !-t

26 value kbuild


dovoc  resolves <vocabulary>
' scan resolves scan