1 files changed, 107 insertions, 0 deletions
diff --git a/libpsn00b/psxsio/tty.c b/libpsn00b/psxsio/tty.c
new file mode 100644
index 0000000..4dc9fd1
--- /dev/null
+++ b/libpsn00b/psxsio/tty.c
@@ -0,0 +1,107 @@
+/*
+ * PSn00bSDK serial port BIOS TTY driver
+ * (C) 2019-2022 Lameguy64, spicyjpeg - MPL licensed
+ *
+ * This driver is designed to be as simple and reliable as possible: as such it
+ * only relies on the SIO_*() API for receiving and sends data synchronously.
+ * This allows printf() to work without issues, albeit slowly, if called from a
+ * critical section or even from an interrupt handler.
+ */
+
+#include <ioctl.h>
+#include <psxapi.h>
+#include <psxsio.h>
+#include <hwregs_c.h>
+
+/* TTY device control block */
+
+static int _sio_open(FCB *fcb, const char* file, int mode) {
+	fcb->diskid = 1;
+	return 0;
+}
+
+static int _sio_inout(FCB *fcb, int cmd) {
+	char *ptr = (char*) fcb->trns_addr;
+
+	switch (cmd) {
+		case 1: // read
+			for (int i = 0; i < fcb->trns_len; i++)
+				*(ptr++) = (char) SIO_ReadByte();
+
+			return fcb->trns_len;
+
+		case 2: // write
+			for (int i = 0; i < fcb->trns_len; i++) {
+				while (!(SIO_STAT & (SR_TXRDY | SR_TXU)))
+					__asm__ volatile("");
+
+				SIO_TXRX = *(ptr++);
+			}
+
+			return fcb->trns_len;
+
+		default:
+			return 0;
+	}
+}
+
+static int _sio_close(FCB *fcb) {
+	return 0;
+}
+
+static int _sio_ioctl(FCB *fcb, int cmd, int arg) {
+	switch (cmd) {
+		case FIOCSCAN:
+			return SIO_ReadSync(1) ? 0 : -1;
+
+		default:
+			return -1;
+	}
+}
+
+static int _sio_dummy(void) {
+	return -1;
+}
+
+static DCB _sio_dcb = {
+	.name			= "tty",
+	.flags			= 3,
+	.ssize			= 1,
+	.desc			= "PSXSIO SERIAL CONSOLE",
+	.f_init			= &_sio_dummy,
+	.f_open			= &_sio_open,
+	.f_inout		= &_sio_inout,
+	.f_close		= &_sio_close,
+	.f_ioctl		= &_sio_ioctl,
+	.f_read			= &_sio_dummy,
+	.f_write		= &_sio_dummy,
+	.f_erase		= &_sio_dummy,
+	.f_undelete		= &_sio_dummy,
+	.f_firstfile	= &_sio_dummy,
+	.f_nextfile		= &_sio_dummy,
+	.f_format		= &_sio_dummy,
+	.f_chdir		= &_sio_dummy,
+	.f_rename		= &_sio_dummy,
+	.f_remove		= &_sio_dummy,
+	.f_testdevice	= &_sio_dummy
+};
+
+/* Public API */
+
+void AddSIO(int baud) {
+	SIO_Init(baud, MR_SB_01 | MR_CHLEN_8);
+
+	close(0);
+	close(1);
+	DelDev(_sio_dcb.name);
+	AddDev(&_sio_dcb);
+	open(_sio_dcb.name, 2);
+	open(_sio_dcb.name, 1);
+}
+
+void DelSIO(void) {
+	SIO_Quit();
+
+	DelDev(_sio_dcb.name);
+	AddDummyTty();
+}