summaryrefslogtreecommitdiffstats
path: root/sw-old/z80/kernel/crt0.s
diff options
context:
space:
mode:
authorNao Pross <naopross@thearcway.org>2018-10-30 11:41:24 +0100
committerNao Pross <naopross@thearcway.org>2018-10-30 11:41:24 +0100
commit43be150dc6e84f6f6eeb071cd3cdb7fc21125d60 (patch)
tree541fd3d690c1bdfd7b68d684029a400b80f4aa06 /sw-old/z80/kernel/crt0.s
parentAdd datasheets for ATmega328 and 74LS259 (diff)
downloadz80uPC-43be150dc6e84f6f6eeb071cd3cdb7fc21125d60.tar.gz
z80uPC-43be150dc6e84f6f6eeb071cd3cdb7fc21125d60.zip
Move sw to sw-old and hw to hw-altium, add kicad files
Diffstat (limited to 'sw-old/z80/kernel/crt0.s')
-rw-r--r--sw-old/z80/kernel/crt0.s103
1 files changed, 103 insertions, 0 deletions
diff --git a/sw-old/z80/kernel/crt0.s b/sw-old/z80/kernel/crt0.s
new file mode 100644
index 0000000..00c7da1
--- /dev/null
+++ b/sw-old/z80/kernel/crt0.s
@@ -0,0 +1,103 @@
+;--------------------------------------------------------------------------
+; 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
+ .globl _kmain
+
+ .area _HEADER (ABS)
+ ;; Reset vector
+ .org 0
+ jp init
+
+ .org 0x08
+ reti
+ .org 0x10
+ reti
+ .org 0x18
+ reti
+ .org 0x20
+ reti
+ .org 0x28
+ reti
+ .org 0x30
+ reti
+ .org 0x38
+ reti
+
+ .org 0x100
+init:
+ ;; Set stack pointer directly above top of memory.
+ ld sp,#0xFFFF
+
+ ;; Initialise global variables
+ call gsinit
+ call _kmain
+ 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
+