Get rid of ack/nack code.

[uccvend-snackrom.git] / ROM2 / sci.c

diff --git a/ROM2/sci.c b/ROM2/sci.c
index 4ce0d36..6ef3cd3 100644 (file)
--- a/ROM2/sci.c
+++ b/ROM2/sci.c
@@ -5,6 +5,9 @@ char sci_tx_buf[BUFFER_LEN];
 volatile char sci_rx_buf[BUFFER_LEN];
 volatile bool sci_have_packet;
 volatile u8 sci_rx_buf_ptr;
+volatile u8 sci_rx_buf_ptr_start;
+volatile bool sci_echo;
+bool sci_doing_xmodem;
 
 void sci_init() {
        /* assumes clock of 4.91Mhz */
@@ -18,9 +21,12 @@ void sci_init() {
 
        sci_have_packet = 0;
        sci_rx_buf_ptr = 0;
+       sci_rx_buf_ptr_start = 0;
+       sci_echo = 0;
+       sci_doing_xmodem = 0;
 }
 
-void send_packet() {
+void send_buffer(bool crlf) {
        char* c;
        for (c = sci_tx_buf; *c; c++) {
                /* wait for TX ready */
@@ -29,30 +35,68 @@ void send_packet() {
                /* send byte */
                _io_ports[M6811_SCDR] = *c;
        }
+       if (!crlf) return;
+       /* send CRLF */
+       while (!(_io_ports[M6811_SCSR] & M6811_TDRE));
+       _io_ports[M6811_SCDR] = '\r';
+       while (!(_io_ports[M6811_SCSR] & M6811_TDRE));
+       _io_ports[M6811_SCDR] = '\n';
+}
+
+void send_string(char* c) {
+       for (; *c; c++) {
+               while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TX ready */
+               _io_ports[M6811_SCDR] = *c; /* send byte */
+       }
+}
+
+char toupper(char c) {
+       if (c >= 'a' && c <= 'z') c -= 'a'-'A';
+       return c;
 }
 
 void sci_rx_int() {
+       char buf = _io_ports[M6811_SCDR];
+       if (sci_doing_xmodem) {
+               if ((sci_rx_buf_ptr+1)%BUFFER_LEN == sci_rx_buf_ptr_start) {
+                       /* we drop following bytes :( */
+                       return;
+               }
+               sci_rx_buf[sci_rx_buf_ptr] = buf;
+               sci_rx_buf_ptr++;
+               sci_rx_buf_ptr %= BUFFER_LEN;
+               return;
+       }
+       if (sci_echo) {
+               while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TX ready */
+               _io_ports[M6811_SCDR] = buf; /* send byte */
+       }
+
+       /* XXX FIXME we should do something about errors. nack? */
        if (sci_have_packet) {
                /* overrun :( */
-               _io_ports[M6811_SCDR]; /* read it anyway */
                return;
        }
-       sci_rx_buf[sci_rx_buf_ptr] = _io_ports[M6811_SCDR];
-       if (sci_rx_buf[sci_rx_buf_ptr] == '\n') {
+       /* we upper case because no commands care that things aren't */
+       sci_rx_buf[sci_rx_buf_ptr] = toupper(buf);
+
+       if (buf == '\n' || buf == '\r') {
                sci_rx_buf[sci_rx_buf_ptr] = '\0';
                sci_have_packet = 1;
-               sci_rx_buf_ptr = 0;
        }
-       sci_rx_buf_ptr++;
-       if (sci_rx_buf_ptr >= BUFFER_LEN) {
-               sci_rx_buf[BUFFER_LEN] = '\0'; /* this is as much as we could fit */
-               sci_have_packet = 1;
-               sci_rx_buf_ptr = 0;
+
+       if (sci_rx_buf_ptr+1 < BUFFER_LEN)
+               sci_rx_buf_ptr++;
+       else {
+               sci_rx_buf[BUFFER_LEN-1] = '\0'; /* this is as much as we could fit */
        }
 }
 
 void sci_interrupt_serial() {
        if (_io_ports[M6811_SCSR] & M6811_RDRF) sci_rx_int();
+
+       if (_io_ports[M6811_SCSR] & M6811_OR)
+               _io_ports[M6811_SCDR]; /* declare it a lost cause */
 }
 
 void msg_clr() {
@@ -60,16 +104,29 @@ void msg_clr() {
        sci_rx_buf_ptr = 0;
 }
 
-void send_ack() {
-       sci_tx_buf[0] = '!';
-       sci_tx_buf[1] = '\n';
-       sci_tx_buf[2] = '\0';
-       send_packet();
+u16 sci_timer;
+void serial_rti() { /* called every 6.6 ms */
+       if (sci_timer) sci_timer--;
 }
 
-void send_nack() {
-       sci_tx_buf[0] = '?';
-       sci_tx_buf[1] = '\n';
-       sci_tx_buf[2] = '\0';
-       send_packet();
+/* for gdb compatibility */
+int serial_readchar(u8 timeout) {
+       int ret;
+       sci_timer = timeout * 152;
+       while (sci_timer && sci_rx_buf_ptr_start == sci_rx_buf_ptr); /* spin */
+       if (sci_timer == 0) return SERIAL_TIMEOUT;
+       ret = sci_rx_buf[sci_rx_buf_ptr_start];
+       sci_rx_buf_ptr_start++;
+       sci_rx_buf_ptr_start %= BUFFER_LEN;
+       return ret;
 }
+
+void serial_write(const char *str, int len) {
+       char *c, *end;
+       end = (char*)(str + len);
+       for (c = (char*)str; c < end; c++) {
+               while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TX ready */
+               _io_ports[M6811_SCDR] = *c; /* send byte */
+       }
+}
+