1 files changed, 80 insertions, 0 deletions
diff --git a/memdump/serial.c b/memdump/serial.c
new file mode 100644
index 00000000..902dcc3d
--- /dev/null
+++ b/memdump/serial.c
@@ -0,0 +1,80 @@
+#include "mystuff.h"
+#include "ymsend.h"
+#include "io.h"
+
+enum {
+  THR = 0,
+  RBR = 0,
+  DLL = 0,
+  DLM = 1,
+  IER = 1,
+  IIR = 2,
+  FCR = 2,
+  LCR = 3,
+  MCR = 4,
+  LSR = 5,
+  MSR = 6,
+  SCR = 7,
+};
+
+int serial_init(struct serial_if *sif)
+{
+  uint16_t port = sif->port;
+  uint8_t dll, dlm, lcr;
+
+  /* Set 115200n81 */
+  outb(0x83, port+LCR);
+  outb(0x01, port+DLL);
+  outb(0x00, port+DLM);
+  (void)inb(port+IER);		/* Synchronize */
+  dll = inb(port+DLL);
+  dlm = inb(port+DLM);
+  lcr = inb(port+LCR);
+  outb(0x03, port+LCR);
+  (void)inb(port+IER);		/* Synchronize */
+
+  if (dll != 0x01 || dlm != 0x00 || lcr != 0x83)
+    return -1;			/* This doesn't look like a serial port */
+
+  /* Disable interrupts */
+  outb(port+IER, 0);
+
+  /* Enable 16550A FIFOs if available */
+  outb(port+FCR, 0x01);		/* Enable FIFO */
+  (void)inb(port+IER);		/* Synchronize */
+  if (inb(port+IIR) < 0xc0)
+    outb(port+FCR, 0x00);	/* Disable FIFOs if non-functional */
+  (void)inb(port+IER);		/* Synchronize */
+
+  return 0;
+}
+
+void serial_write(struct serial_if *sif, const void *data, size_t n)
+{
+  uint16_t port = sif->port;
+  const char *p = data;
+  uint8_t lsr;
+
+  while (n--) {
+    do {
+      lsr = inb(port+LSR);
+    } while (!(lsr & 0x20));
+
+    outb(*p++, port+THR);
+  }
+}
+
+void serial_read(struct serial_if *sif, void *data, size_t n)
+{
+  uint16_t port = sif->port;
+  char *p = data;
+  uint8_t lsr;
+
+  while (n--) {
+    do {
+      lsr = inb(port+LSR);
+    } while (!(lsr & 0x01));
+
+    *p++ = inb(port+RBR);
+  }
+}