freebsd-dev/sys/conf/options.pc98
Poul-Henning Kamp dad3b6c6fd Back in the good old days, PC's had random pieces of rock for
frequency generation and what frequency the generated was anyones
guess.

In general the 32.768kHz RTC clock x-tal was the best, because that
was a regular wrist-watch Xtal, whereas the X-tal generating the
ISA bus frequency was much lower quality, often costing as much as
several cents a piece, so it made good sense to check the ISA bus
frequency against the RTC clock.

The other relevant property of those machines, is that they
typically had no more than 16MB RAM.

These days, CPU chips croak if their clocks are not tightly within
specs and all necessary frequencies are derived from the master
crystal by means if PLL's.

Considering that it takes on average 1.5 second to calibrate the
frequency of the i8254 counter, that more likely than not, we will
not actually use the result of the calibration, and as the final
clincher, we seldom use the i8254 for anything besides BEL in
syscons anyway, it has become time to drop the calibration code.

If you need to tell the system what frequency your i8254 runs,
you can do so from the loader using hw.i8254.freq or using the
sysctl kern.timecounter.tc.i8254.frequency.
2008-03-26 22:12:00 +00:00

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# $FreeBSD$
# Options specific to the pc98 platform kernels
AUTO_EOI_1 opt_auto_eoi.h
BROKEN_KEYBOARD_RESET opt_reset.h
COUNT_XINVLTLB_HITS opt_smp.h
COUNT_IPIS opt_smp.h
DISABLE_PG_G opt_pmap.h
DISABLE_PSE opt_pmap.h
I586_PMC_GUPROF opt_i586_guprof.h
MAXMEM
MPTABLE_FORCE_HTT
MP_WATCHDOG
PERFMON
PMAP_SHPGPERPROC opt_pmap.h
POWERFAIL_NMI opt_trap.h
# Options for emulators. These should only be used at config time, so
# they are handled like options for static filesystems
# (see src/sys/conf/options), except for broken debugging options.
COMPAT_AOUT opt_dontuse.h
IBCS2 opt_dontuse.h
COMPAT_LINUX opt_dontuse.h
COMPAT_SVR4 opt_dontuse.h
DEBUG_SVR4 opt_svr4.h
LINPROCFS opt_dontuse.h
LINSYSFS opt_dontuse.h
PECOFF_DEBUG opt_pecoff.h
PECOFF_SUPPORT opt_dontuse.h
# Change KVM size. Changes things all over the kernel.
KVA_PAGES opt_global.h
TIMER_FREQ opt_clock.h
# options for serial support
COM_ESP opt_sio.h
COM_MULTIPORT opt_sio.h
CONSPEED opt_sio.h
GDBSPEED opt_sio.h
CPU_BLUELIGHTNING_3X opt_cpu.h
CPU_BLUELIGHTNING_FPU_OP_CACHE opt_cpu.h
CPU_BTB_EN opt_cpu.h
CPU_CYRIX_NO_LOCK opt_cpu.h
CPU_DIRECT_MAPPED_CACHE opt_cpu.h
CPU_DISABLE_5X86_LSSER opt_cpu.h
CPU_DISABLE_CMPXCHG opt_global.h # XXX global, unlike other CPU_*
CPU_DISABLE_SSE opt_cpu.h
CPU_FASTER_5X86_FPU opt_cpu.h
CPU_GEODE opt_cpu.h
CPU_I486_ON_386 opt_cpu.h
CPU_IORT opt_cpu.h
CPU_L2_LATENCY opt_cpu.h
CPU_LOOP_EN opt_cpu.h
CPU_PPRO2CELERON opt_cpu.h
CPU_RSTK_EN opt_cpu.h
CPU_SOEKRIS opt_cpu.h
CPU_SUSP_HLT opt_cpu.h
CPU_UPGRADE_HW_CACHE opt_cpu.h
CPU_WT_ALLOC opt_cpu.h
CYRIX_CACHE_REALLY_WORKS opt_cpu.h
CYRIX_CACHE_WORKS opt_cpu.h
NO_F00F_HACK opt_cpu.h
NO_MEMORY_HOLE opt_cpu.h
# The CPU type affects the endian conversion functions all over the kernel.
I486_CPU opt_global.h
I586_CPU opt_global.h
I686_CPU opt_global.h
GDC
# Video spigot
SPIGOT_UNSECURE opt_spigot.h
# Enables NETGRAPH support for Cronyx adapters
NETGRAPH_CRONYX opt_ng_cronyx.h
# -------------------------------
# isdn4bsd: passive PCI cards
# -------------------------------
ELSA_QS1PCI opt_i4b.h
# -------------------------------
# isdn4bsd: misc options
# -------------------------------
# temporary workaround for SMP machines
I4B_SMP_WORKAROUND opt_i4b.h
# enable VJ compression code for ipr i/f
#XXXBZ#IPR_VJ opt_i4b.h
#XXXBZ#IPR_LOG opt_i4b.h
# ct driver options
CT_BUS_WEIGHT opt_ct.h
CT_USE_RELOCATE_OFFSET opt_ct.h
# npx options
FPU_ERROR_BROKEN opt_npx.h
# PC98 options
EPSON_BOUNCEDMA opt_pc98.h
EPSON_MEMWIN opt_pc98.h
LINE30 opt_syscons.h
PC98 opt_global.h
# Device options
DEV_APIC opt_apic.h
DEV_MECIA opt_mecia.h
DEV_NPX opt_npx.h
# Debugging
NPX_DEBUG opt_npx.h
STOP_NMI opt_cpu.h
# BPF just-in-time compiler
BPF_JITTER opt_bpf.h