diff options
Diffstat (limited to '')
| -rw-r--r-- | sw/z80/tests/pio/crt0.s | 134 |
1 files changed, 35 insertions, 99 deletions
diff --git a/sw/z80/tests/pio/crt0.s b/sw/z80/tests/pio/crt0.s index c272f06..eabe06c 100644 --- a/sw/z80/tests/pio/crt0.s +++ b/sw/z80/tests/pio/crt0.s @@ -1,104 +1,40 @@ -;-------------------------------------------------------------------------- -; crt0.s - Generic crt0.s for a Z80 -; -; Copyright (C) 2000, Michael Hope -; -; This library is free software; you can redistribute it and/or modify it -; under the terms of the GNU General Public License as published by the -; Free Software Foundation; either version 2, or (at your option) any -; later version. -; -; This library is distributed in the hope that it will be useful, -; but WITHOUT ANY WARRANTY; without even the implied warranty of -; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -; GNU General Public License for more details. -; -; You should have received a copy of the GNU General Public License -; along with this library; see the file COPYING. If not, write to the -; Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, -; MA 02110-1301, USA. -; -; As a special exception, if you link this library with other files, -; some of which are compiled with SDCC, to produce an executable, -; this library does not by itself cause the resulting executable to -; be covered by the GNU General Public License. This exception does -; not however invalidate any other reasons why the executable file -; might be covered by the GNU General Public License. -;-------------------------------------------------------------------------- + .module crt0 + .area _HEADER (ABS) - .module crt0 - .globl _main +;; Reset vectors + .org 0 + jp init - .area _HEADER (ABS) - ;; Reset vector - .org 0 - jp init + .org 0x38 ; the instruction 0xff (not written) resets to this location + jp init - .org 0x08 - reti - .org 0x10 - reti - .org 0x18 - reti - .org 0x20 - reti - .org 0x28 - reti - .org 0x30 - reti - .org 0x38 - reti +;; main code + .org 0x100 + .globl _main - .org 0x100 init: - ;; Set stack pointer directly above top of memory. - ld sp,#0xFFFF - - ;; Initialise global variables - call gsinit - call _main - jp _exit - - ;; Ordering of segments for the linker. - .area _HOME - .area _CODE - .area _INITIALIZER - .area _GSINIT - .area _GSFINAL - - .area _DATA - .area _INITIALIZED - .area _BSEG - .area _BSS - .area _HEAP - - .area _CODE - -__clock:: - ld a,#2 - rst 0x08 - ret - -_exit:: - ;; Exit - special code to the emulator - ld a,#0 - rst 0x08 -1$: - halt - jr 1$ - - .area _GSINIT -gsinit:: - ; ld bc, #l__INITIALIZER - ld a, b - or a, c - jr Z, gsinit_next - ; ld de, #s__INITIALIZED - ; ld hl, #s__INITIALIZER - ldir - -gsinit_next: - - .area _GSFINAL - ret - + ;; Set stack pointer directly above top of memory. + ld sp,#0xffff + + ;; Start of the program + call _main + jp _exit + +_exit: + halt + ; jp _exit + +;; Ordering of segments for the linker. + .area _HOME + .area _CODE + .area _INITIALIZER + .area _GSINIT + .area _GSFINAL + + .area _DATA + .area _INITIALIZED + .area _BSEG + .area _BSS + .area _HEAP + + .area _CODE
\ No newline at end of file |