ack/plat/cpm/boot.s

163 lines
3.1 KiB
ArmAsm

#
! $Source$
! $State$
! $Revision$
! Declare segments (the order is important).
.sect .text
.sect .rom
.sect .data
.sect .bss
MAX_ARGV = 8
.sect .bss
STACKSIZE = 2*1024
.comm stack, STACKSIZE
.comm oldstack, 2
.sect .text
begtext:
! The absolute first thing we have to do is to clear the bss. (argify
! requires it.)
lxi h, begbss
lxi b, endbss
mvi e, 0
1:
mov m, e
inx h
mov a, b
cmp h
jnz 1b
mov a, c
cmp l
jnz 1b
! Set up the stack (now it's been cleared, since it's in the BSS).
lxi sp, oldstack + STACKSIZE
! C-ify the command line at 0x0080.
lxi h, 0x0080
mov a, m ! a = length of command line
cpi 0x7F ! 127-byte command lines...
jnz 1f
dcr a ! ...lose the last character
1:
adi 0x81 ! write a 0 at 0x0081+length
mov l, a
mov m, h
! Now argify it.
lxi b, 0x0081 ! bc = command line pointer
lxi d, argv ! de = argv pointer
ldax b ! peek for any leading whitespace
ora a
cpi ' '
jz 3f
1: xchg ! write out the next argument
mov m, c
inx h
mov m, b
inx h
xchg
lda argc ! exit if this was the last argument
inr a
sta argc
cpi MAX_ARGV
jz end_of_argify
2: inx b ! scan for whitespace
ldax b
ora a
jz end_of_argify
cpi ' '
jnz 2b
xra a ! replace the space with a \0
stax b
3: inx b ! scan for non-whitespace
ldax b
ora a
jz end_of_argify
cpi ' '
jz 3b
jmp 1b
end_of_argify:
! Add the fake parameter for the program name.
lxi h, progname
shld argv0
lxi h, argc
inr m
! Push the main() arguments and go.
lxi h, envp
push h
lxi h, argv0
push h
lhld argc ! slightly evil
mvi h, 0
push h
call __m_a_i_n
jmp EXIT
! Emergency exit routine.
.define EXIT, __exit
EXIT:
__exit:
rst 0
! Define symbols at the beginning of our various segments, so that we can find
! them. (Except .text, which has already been done.)
.define begtext, begdata, begbss
.sect .data; begdata:
.sect .rom; begrom:
.sect .bss; begbss:
! Some magic data. All EM systems need these.
.define .trppc, .ignmask, _errno
.comm .trppc, 2
.comm .ignmask, 2
.comm _errno, 2
! Used to store the argv array.
argc: .space 1 ! number of args
argv0: .space 2 ! always points at progname
argv: .space 2*MAX_ARGV ! argv array (must be after argv0)
envp: .space 2 ! envp array (always empty, must be after argv)
! These are used specifically by the i80 code generator.
.define .trapproc, .retadr, .retadr1
.define .bcreg, .areg
.define .tmp1, .fra, block1, block2, block3
.comm .trapproc, 2
.comm .retadr, 2 ! used to save return address
.comm .retadr1, 2 ! reserve
.comm .bcreg, 2
.comm .areg, 1
.comm .tmp1, 2
.comm .fra, 8 ! 8 bytes function return area
block1: .space 4 ! used by 32 bits divide and
block2: .space 4 ! multiply routines
block3: .space 4 ! must be contiguous (.comm doesn't guarantee this)
.sect .rom
progname: .asciz 'ACKCPM'