* Patch by Daniel Engström, 13 Nov 2002:
Add support for i386 architecture and AMD SC520 board
* Patch by Pierre Aubert, 12 Nov 2002:
Add support for DOS filesystem and booting from DOS floppy disk
diff --git a/cpu/i386/timer.c b/cpu/i386/timer.c
new file mode 100644
index 0000000..a23cd6e
--- /dev/null
+++ b/cpu/i386/timer.c
@@ -0,0 +1,211 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/i8254.h>
+#include <asm/ibmpc.h>
+
+
+static volatile unsigned long system_ticks;
+static int timer_init_done =0;
+
+static void timer_isr(void *unused)
+{
+ system_ticks++;
+}
+
+unsigned long get_system_ticks(void)
+{
+ return system_ticks;
+}
+
+#define TIMER0_VALUE 0x04aa /* 1kHz 1.9318MHz / 1000 */
+#define TIMER2_VALUE 0x0a8e /* 440Hz */
+
+int timer_init(void)
+{
+ system_ticks = 0;
+
+ irq_install_handler(0, timer_isr, NULL);
+
+ /* initialize timer 0 and 2
+ *
+ * Timer 0 is used to increment system_tick 1000 times/sec
+ * Timer 1 was used for DRAM refresh in early PC's
+ * Timer 2 is used to drive the speaker
+ * (to stasrt a beep: write 3 to port 0x61,
+ * to stop it again: write 0)
+ */
+
+ outb(PIT_CMD_CTR0|PIT_CMD_BOTH|PIT_CMD_MODE2, PIT_BASE + PIT_COMMAND);
+ outb(TIMER0_VALUE&0xff, PIT_BASE + PIT_T0);
+ outb(TIMER0_VALUE>>8, PIT_BASE + PIT_T0);
+
+ outb(PIT_CMD_CTR2|PIT_CMD_BOTH|PIT_CMD_MODE3, PIT_BASE + PIT_COMMAND);
+ outb(TIMER2_VALUE&0xff, PIT_BASE + PIT_T2);
+ outb(TIMER2_VALUE>>8, PIT_BASE + PIT_T2);
+
+ timer_init_done = 1;
+
+ return 0;
+}
+
+
+#ifdef CFG_TIMER_GENERIC
+
+/* the unit for these is CFG_HZ */
+
+/* FixMe: implement these */
+void reset_timer (void)
+{
+ system_ticks = 0;
+}
+
+ulong get_timer (ulong base)
+{
+ return (system_ticks - base);
+}
+
+void set_timer (ulong t)
+{
+ system_ticks = t;
+}
+
+static u16 read_pit(void)
+{
+ u8 low;
+ outb(PIT_CMD_LATCH, PIT_BASE + PIT_COMMAND);
+ low = inb(PIT_BASE + PIT_T0);
+ return ((inb(PIT_BASE + PIT_T0) << 8) | low);
+}
+
+/* this is not very exact */
+void udelay (unsigned long usec)
+{
+ int counter;
+ int wraps;
+
+ if (!timer_init_done) {
+ return;
+ }
+ counter = read_pit();
+ wraps = usec/1000;
+ usec = usec%1000;
+
+ usec*=1194;
+ usec/=1000;
+ usec+=counter;
+ if (usec > 1194) {
+ usec-=1194;
+ wraps++;
+ }
+
+ while (1) {
+ int new_count = read_pit();
+
+ if (((new_count < usec) && !wraps) || wraps < 0) {
+ break;
+ }
+
+ if (new_count > counter) {
+ wraps--;
+ }
+ counter = new_count;
+ }
+
+}
+
+#if 0
+/* this is a version with debug output */
+void _udelay (unsigned long usec)
+{
+ int counter;
+ int wraps;
+
+ int usec1, usec2, usec3;
+ int wraps1, wraps2, wraps3, wraps4;
+ int ctr1, ctr2, ctr3, nct1, nct2;
+ int i;
+ usec1=usec;
+ if (!timer_init_done) {
+ return;
+ }
+ counter = read_pit();
+ ctr1 = counter;
+ wraps = usec/1000;
+ usec = usec%1000;
+
+ usec2 = usec;
+ wraps1 = wraps;
+
+ usec*=1194;
+ usec/=1000;
+ usec+=counter;
+ if (usec > 1194) {
+ usec-=1194;
+ wraps++;
+ }
+
+ usec3 = usec;
+ wraps2 = wraps;
+
+ ctr2 = wraps3 = nct1 = 4711;
+ ctr3 = wraps4 = nct2 = 4711;
+ i=0;
+ while (1) {
+ int new_count = read_pit();
+ i++;
+ if ((new_count < usec && !wraps) || wraps < 0) {
+ break;
+ }
+
+ if (new_count > counter) {
+ wraps--;
+ }
+ if (ctr2==4711) {
+ ctr2 = counter;
+ wraps3 = wraps;
+ nct1 = new_count;
+ } else {
+ ctr3 = counter;
+ wraps4 = wraps;
+ nct2 = new_count;
+ }
+
+ counter = new_count;
+ }
+
+ printf("udelay(%d)\n", usec1);
+ printf("counter %d\n", ctr1);
+ printf("1: wraps %d, usec %d\n", wraps1, usec2);
+ printf("2: wraps %d, usec %d\n", wraps2, usec3);
+ printf("new_count[0] %d counter %d wraps %d\n", nct1, ctr2, wraps3);
+ printf("new_count[%d] %d counter %d wraps %d\n", i, nct2, ctr3, wraps4);
+
+ printf("%d %d %d %d %d\n",
+ read_pit(), read_pit(), read_pit(),
+ read_pit(), read_pit());
+}
+#endif
+#endif