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authorNao Pross <naopross@thearcway.org>2017-06-16 13:57:39 +0200
committerNao Pross <naopross@thearcway.org>2017-06-16 13:57:39 +0200
commit08fc6f3fd4461bfc78cd279809e1bf173e9f646e (patch)
tree3194ab2330128c74e2a9ced876b526931358dd6a /sw/z80/crt0.s
parentmerge branch 'hardware' (diff)
parentfixed typo in usart.h and in doc (diff)
downloadz80uPC-08fc6f3fd4461bfc78cd279809e1bf173e9f646e.tar.gz
z80uPC-08fc6f3fd4461bfc78cd279809e1bf173e9f646e.zip
merge branch 'naopross'
merge to get the new doc on master
Diffstat (limited to '')
-rw-r--r--sw/z80/crt0.s125
1 files changed, 99 insertions, 26 deletions
diff --git a/sw/z80/crt0.s b/sw/z80/crt0.s
index d0ae3ca..00c7da1 100644
--- a/sw/z80/crt0.s
+++ b/sw/z80/crt0.s
@@ -1,30 +1,103 @@
- .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
+;--------------------------------------------------------------------------
+; 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
- ld sp,#0xFFFF
+ ;; 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:
- ;; call C main function
- call _main
+ .area _GSFINAL
+ ret
-.globl _main