Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / arch / i386 / interface / pcbios / bios_timer.c

diff --git a/qemu/roms/ipxe/src/arch/i386/interface/pcbios/bios_timer.c b/qemu/roms/ipxe/src/arch/i386/interface/pcbios/bios_timer.c
new file mode 100644 (file)
index 0000000..65bbf9e
--- /dev/null
+++ b/qemu/roms/ipxe/src/arch/i386/interface/pcbios/bios_timer.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * BIOS timer
+ *
+ */
+
+#include <ipxe/timer.h>
+#include <realmode.h>
+#include <bios.h>
+
+/**
+ * Get current system time in ticks
+ *
+ * @ret ticks          Current time, in ticks
+ *
+ * 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 unsigned long 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__ ( "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 );
+}
+
+PROVIDE_TIMER_INLINE ( pcbios, udelay );
+PROVIDE_TIMER ( pcbios, currticks, bios_currticks );
+PROVIDE_TIMER_INLINE ( pcbios, ticks_per_sec );