Introduce the new timer subsystem.

	Timer subsystem initialization code in core/timer.c

	Split the BIOS and RTDSC timer drivers from i386_timer.c

	Split arch/i386/firmware/pcbios/bios.c into the RTSDC
	timer driver and arch/i386/core/nap.c

	Split the headers properly:
		include/unistd.h - delay functions to be used by the
					gPXE core and drivers.

		include/gpxe/timer.h - the fimer subsystem interface
					to be used by the timer drivers
					and currticks() to be used by
					the code gPXE subsystems.

		include/latch.h	- removed
		include/timer.h - scheduled for removal. Some driver
					are using currticks, which is
					only for core subsystems.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/src/arch/i386/drivers/timer_bios.c b/src/arch/i386/drivers/timer_bios.c
new file mode 100644
index 000000000..f9caf8d9a
--- /dev/null
+++ b/src/arch/i386/drivers/timer_bios.c
@@ -0,0 +1,57 @@
+/*
+ * Etherboot routines for PCBIOS firmware.
+ *
+ * Body of routines taken from old pcbios.S
+ */
+
+#include <gpxe/init.h>
+#include <gpxe/timer.h>
+#include <stdio.h>
+#include <realmode.h>
+#include <bios.h>
+#include <bits/timer2.h>
+
+/* A bit faster actually, but we don't care. */
+#define	TIMER2_TICKS_PER_SEC	18
+
+/*
+ * Use direct memory access to BIOS variables, longword 0040:006C (ticks
+ * today) and byte 0040:0070 (midnight crossover flag) instead of calling
+ * timeofday BIOS interrupt.
+ */
+
+static tick_t bios_currticks ( void ) {
+	static int days = 0;
+	uint32_t ticks;
+	uint8_t midnight;
+
+	/* Re-enable interrupts so that the timer interrupt can occur */
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "nop\n\t"
+					   "nop\n\t"
+					   "cli\n\t" ) : : );
+
+	get_real ( ticks, BDA_SEG, 0x006c );
+	get_real ( midnight, BDA_SEG, 0x0070 );
+
+	if ( midnight ) {
+		midnight = 0;
+		put_real ( midnight, BDA_SEG, 0x0070 );
+		days += 0x1800b0;
+	}
+
+	return ( (days + ticks) * (USECS_IN_SEC / TIMER2_TICKS_PER_SEC) );
+}
+
+static int bios_ts_init(void)
+{
+	DBG("BIOS timer installed\n");
+	return 0;
+}
+
+struct timer bios_ts __timer ( 02 ) = {
+	.init = bios_ts_init,
+	.udelay = i386_timer2_udelay,
+	.currticks = bios_currticks,
+};
+