avr: initial commit

[z80.git] / avr / main.c

diff --git a/avr/main.c b/avr/main.c
new file mode 100644 (file)
index 0000000..8e6510a
--- /dev/null
+++ b/avr/main.c
@@ -0,0 +1,84 @@
+/* Z80 Mainboard Controller */
+
+#include <stdio.h>
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include <util/delay.h>
+
+#include "uart.h"
+#include "bus.h"
+#include "i2c.h"
+#include "mem.h"
+#include "io.h"
+
+#include "monitor.h"
+
+uint8_t xorshift(uint8_t new_seed)
+{
+       static uint8_t seed = 0xA5;
+       if(new_seed) seed=new_seed;
+
+       seed ^= (seed << 1);
+       seed ^= (seed >> 1);
+       seed ^= (seed << 2);
+       return(seed);
+}
+
+int main(void)
+{
+       /* initialize serial port and stdin/stdout */
+       uart_init();
+       stdout = &uart_out;
+       stdin  = &uart_in;
+       sei();
+
+       /* initialize hardware and monitor */
+       printf_P(PSTR("\nAVR INIT "));
+       printf_P(PSTR("[BUS")); bus_init(); printf_P(PSTR("] "));
+       printf_P(PSTR("[I2C")); i2c_init(); printf_P(PSTR("] "));
+       printf_P(PSTR("[MEM")); mem_init(); printf_P(PSTR("] "));
+       printf_P(PSTR("[I/O"));  io_init(); printf_P(PSTR("] "));
+       printf_P(PSTR("[MON] ")); monitor_init();
+       printf_P(PSTR("DONE.\nSend BREAK to enter monitor.\n"));
+
+       /* load initial program into memory */
+       menu_ihex();
+
+#if 0
+       mem_start();
+       for(uint8_t i = 0; i < 8; i++) printf("%02x ", mem_read(i));
+       mem_stop();
+#endif
+
+       /* reset Z80 */
+       printf_P(PSTR("Go!\n"));
+       bus_reset();
+       bus_unlock();
+       bus_wait();
+
+       while(1) {
+               if(!(MEMPIN & (1 << SEL))) {    /* got I/O request */
+
+                       /* answer the I/O request */
+                       if(!(MEMPIN & (1 << RD))) {
+//                             printf_P(PSTR("<IORD>"));
+                               io_read();
+                       } else if(!(MEMPIN & (1 << WR))) {
+//                             printf_P(PSTR("<IOWR>"));
+                               io_write();
+                       } else {
+                               printf_P(PSTR("<IOFAIL>"));
+                               while(1);
+                       }
+
+                       while(!(MEMPIN & (1 << SEL)));
+               }
+
+               if(uart_break) monitor();       /* enter monitor on break */
+       }
+
+       printf_P(PSTR("\nAVR END\n"));
+       while(1);
+}