6 files changed, 98 insertions, 0 deletions
diff --git a/sw/z80/crt0.s.old b/sw/z80/crt0.s.old
new file mode 100644
index 0000000..f3bf8e8
--- /dev/null
+++ b/sw/z80/crt0.s.old
@@ -0,0 +1,43 @@
+    .module crt0
+    .globl  _main
+
+    .area _HEADER (ABS)
+;; reset vector
+    .org 0x0000 
+    jp    init
+    
+    .org 0x0100
+
+init:
+;; Stack at the 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     _GSINIT
+    .area     _GSFINAL
+
+    .area _DATA
+    .area     _BSS
+    .area     _HEAP
+
+    .area     _CODE
+__clock::
+    ret
+    
+_exit::
+    ret
+    
+    .area     _GSINIT
+
+gsinit::    
+
+.area _GSFINAL
+    ret
+
diff --git a/sw/z80/kernel.c b/sw/z80/kernel.c
new file mode 100644
index 0000000..172eee1
--- /dev/null
+++ b/sw/z80/kernel.c
@@ -0,0 +1,7 @@
+#include "types.h"
+
+
+void main(void)
+{
+
+}
diff --git a/sw/z80/loader.asm b/sw/z80/loader.asm
new file mode 100644
index 0000000..85f5abe
--- /dev/null
+++ b/sw/z80/loader.asm
@@ -0,0 +1,18 @@
+; C crt0 loader
+;
+    module crt0
+
+; general scope declarations
+    extern _main    ; C code
+
+; startup code
+    org 0000h ; reset vector
+    jp _start
+
+_start:
+    ld sp, 0xffff
+    call _main
+    jp _exit
+
+_exit:
+    ret
diff --git a/sw/z80/serial.h b/sw/z80/serial.h
new file mode 100644
index 0000000..3dc9b18
--- /dev/null
+++ b/sw/z80/serial.h
@@ -0,0 +1,15 @@
+#ifndef __SERIAL_H__
+#define __SERIAL_H__
+
+#include "types.h"
+
+// define all
+#define USART_BAUD_9600
+#define USART_BAUD_115200
+
+uint8_t usart_registers[8];
+usart_registers = 0x80FF; // TODO: set real address
+
+void usart_init(int16_t baudprescale);
+
+#endif
diff --git a/sw/z80/types.h b/sw/z80/types.h
new file mode 100644
index 0000000..adde214
--- /dev/null
+++ b/sw/z80/types.h
@@ -0,0 +1,9 @@
+#ifndef __TYPES_H__
+#define __TYPES_H__
+
+#define int8_t      char
+#define uint8_t     unsigned char
+#define int16_t     int
+#define uint16_t    unsigned int
+
+#endif
diff --git a/sw/z80/zcc_opt.def b/sw/z80/zcc_opt.def
new file mode 100644
index 0000000..de830a9
--- /dev/null
+++ b/sw/z80/zcc_opt.def
@@ -0,0 +1,6 @@
+
+IF !DEFINED_startup
+	defc	DEFINED_startup = 1
+	defc startup = 1
+ENDIF
+