diff options
Diffstat (limited to 'qemu/roms/seabios/src/hw/timer.c')
| -rw-r--r-- | qemu/roms/seabios/src/hw/timer.c | 25 |
1 files changed, 10 insertions, 15 deletions
diff --git a/qemu/roms/seabios/src/hw/timer.c b/qemu/roms/seabios/src/hw/timer.c index 5edc9fdbb..03d22b2f5 100644 --- a/qemu/roms/seabios/src/hw/timer.c +++ b/qemu/roms/seabios/src/hw/timer.c @@ -49,8 +49,8 @@ #define PMTIMER_HZ 3579545 // Underlying Hz of the PM Timer #define PMTIMER_TO_PIT 3 // Ratio of pmtimer rate to pit rate -u32 TimerKHz VARFSEG; -u16 TimerPort VARFSEG; +u32 TimerKHz VARFSEG = DIV_ROUND_UP(PMTIMER_HZ, 1000 * PMTIMER_TO_PIT); +u16 TimerPort VARFSEG = PORT_PIT_COUNTER0; u8 ShiftTSC VARFSEG; @@ -92,6 +92,7 @@ tsctimer_setup(void) t = (t + 1) >> 1; } TimerKHz = DIV_ROUND_UP((u32)t, 1000 * PMTIMER_TO_PIT); + TimerPort = 0; dprintf(1, "CPU Mhz=%u\n", (TimerKHz << ShiftTSC) / 1000); } @@ -100,24 +101,16 @@ tsctimer_setup(void) void timer_setup(void) { - if (CONFIG_PMTIMER && TimerPort) { - dprintf(3, "pmtimer already configured; will not calibrate TSC\n"); + if (!CONFIG_TSC_TIMER || (CONFIG_PMTIMER && TimerPort != PORT_PIT_COUNTER0)) return; - } + // Check if CPU has a timestamp counter u32 eax, ebx, ecx, edx, cpuid_features = 0; cpuid(0, &eax, &ebx, &ecx, &edx); if (eax > 0) cpuid(1, &eax, &ebx, &ecx, &cpuid_features); - - if (!(cpuid_features & CPUID_TSC)) { - TimerPort = PORT_PIT_COUNTER0; - TimerKHz = DIV_ROUND_UP(PMTIMER_HZ, 1000 * PMTIMER_TO_PIT); - dprintf(3, "386/486 class CPU. Using TSC emulation\n"); - return; - } - - tsctimer_setup(); + if (cpuid_features & CPUID_TSC) + tsctimer_setup(); } void @@ -154,7 +147,7 @@ static u32 timer_read(void) { u16 port = GET_GLOBAL(TimerPort); - if (!port) + if (CONFIG_TSC_TIMER && !port) // Read from CPU TSC return rdtscll() >> GET_GLOBAL(ShiftTSC); if (CONFIG_PMTIMER && port != PORT_PIT_COUNTER0) @@ -249,6 +242,8 @@ ticks_from_ms(u32 ms) void pit_setup(void) { + if (!CONFIG_HARDWARE_IRQ) + return; // timer0: binary count, 16bit count, mode 2 outb(PM_SEL_TIMER0|PM_ACCESS_WORD|PM_MODE2|PM_CNT_BINARY, PORT_PIT_MODE); // maximum count of 0000H = 18.2Hz |