summaryrefslogtreecommitdiffstats
path: root/contrib/syslinux-4.02/com32/sysdump/serial.c
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/syslinux-4.02/com32/sysdump/serial.c')
-rw-r--r--contrib/syslinux-4.02/com32/sysdump/serial.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/sysdump/serial.c b/contrib/syslinux-4.02/com32/sysdump/serial.c
new file mode 100644
index 0000000..a398753
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/sysdump/serial.c
@@ -0,0 +1,169 @@
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <console.h>
+#include <sys/io.h>
+#include <sys/cpu.h>
+#include <syslinux/config.h>
+
+#include "serial.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, const char *argv[])
+{
+ const struct syslinux_serial_console_info *sci
+ = syslinux_serial_console_info();
+ uint16_t port;
+ unsigned int divisor;
+ uint8_t dll, dlm, lcr;
+
+ if (!argv[0]) {
+ if (sci->iobase) {
+ port = sci->iobase;
+ } else {
+ printf("No port number specified and not using serial console!\n");
+ return -1;
+ }
+ } else {
+ port = strtoul(argv[0], NULL, 0);
+ if (port <= 3) {
+ uint16_t addr = ((uint16_t *)0x400)[port];
+ if (!addr) {
+ printf("No serial port address found!\n");
+ return -1;
+ }
+ printf("Serial port %u is at 0x%04x\n", port, addr);
+ port = addr;
+ }
+ }
+
+ sif->port = port;
+ sif->console = false;
+
+ divisor = 1; /* Default speed = 115200 bps */
+
+ /* Check to see if this is the same as the serial console */
+ if (port == sci->iobase) {
+ /* Overlaying the console... */
+ sif->console = true;
+
+ /* Default to already configured speed */
+ divisor = sci->divisor;
+
+ /* Shut down I/O to the console for the time being */
+ openconsole(&dev_null_r, &dev_null_w);
+ }
+
+ if (argv[0] && argv[1])
+ divisor = 115200/strtoul(argv[1], NULL, 0);
+
+ cli(); /* Just in case... */
+
+ /* Save old register settings */
+ sif->old.lcr = inb(port + LCR);
+ sif->old.mcr = inb(port + MCR);
+ sif->old.iir = inb(port + IIR);
+
+ /* Set speed */
+ outb(0x83, port + LCR); /* Enable divisor access */
+ sif->old.dll = inb(port + DLL);
+ sif->old.dlm = inb(port + DLM);
+ outb(divisor, port + DLL);
+ outb(divisor >> 8, port + DLM);
+ (void)inb(port + IER); /* Synchronize */
+
+ dll = inb(port + DLL);
+ dlm = inb(port + DLM);
+ lcr = inb(port + LCR);
+ outb(0x03, port + LCR); /* Enable data access, n81 */
+ (void)inb(port + IER); /* Synchronize */
+ sif->old.ier = inb(port + IER);
+
+ /* Disable interrupts */
+ outb(0, port + IER);
+
+ sti();
+
+ if (dll != (uint8_t)divisor ||
+ dlm != (uint8_t)(divisor >> 8) ||
+ lcr != 0x83) {
+ serial_cleanup(sif);
+ printf("No serial port detected!\n");
+ return -1; /* This doesn't look like a serial port */
+ }
+
+ /* Enable 16550A FIFOs if available */
+ outb(0x01, port + FCR); /* Enable FIFO */
+ (void)inb(port + IER); /* Synchronize */
+ if (inb(port + IIR) < 0xc0)
+ outb(0x00, port + FCR); /* 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);
+ }
+}
+
+void serial_cleanup(struct serial_if *sif)
+{
+ uint16_t port = sif->port;
+
+ outb(0x83, port + LCR);
+ (void)inb(port + IER);
+ outb(sif->old.dll, port + DLL);
+ outb(sif->old.dlm, port + DLM);
+ (void)inb(port + IER);
+ outb(sif->old.lcr & 0x7f, port + LCR);
+ (void)inb(port + IER);
+ outb(sif->old.mcr, port + MCR);
+ outb(sif->old.ier, port + IER);
+ if (sif->old.iir < 0xc0)
+ outb(0x00, port + FCR); /* Disable FIFOs */
+
+ /* Re-enable console messages, if we shut them down */
+ if (sif->console)
+ openconsole(&dev_null_r, &dev_stdcon_w);
+}