opengnsys_ipxe/src/interface
Michael Brown 302f1eeb80 [time] Allow timer to be selected at runtime
Allow the active timer (providing udelay() and currticks()) to be
selected at runtime based on probing during the INIT_EARLY stage of
initialisation.

TICKS_PER_SEC is now a fixed compile-time constant for all builds, and
is independent of the underlying clock tick rate.  We choose the value
1024 to allow multiplications and divisions on seconds to be converted
to bit shifts.

TICKS_PER_MS is defined as 1, allowing multiplications and divisions
on milliseconds to be omitted entirely.  The 2% inaccuracy in this
definition is negligible when using the standard BIOS timer (running
at around 18.2Hz).

TIMER_RDTSC now checks for a constant TSC before claiming to be a
usable timer.  (This timer can be tested in KVM via the command-line
option "-cpu host,+invtsc".)

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-01-26 08:17:37 +00:00
..
bofm [pci] Support systems with multiple PCI root bridges 2016-06-09 09:36:28 +01:00
efi [time] Allow timer to be selected at runtime 2017-01-26 08:17:37 +00:00
hyperv [hyperv] Ignore unsolicited VMBus messages 2017-01-24 15:03:10 +00:00
linux [time] Allow timer to be selected at runtime 2017-01-26 08:17:37 +00:00
smbios [settings] Expose SMBIOS settings as global variables 2015-12-23 15:29:55 +00:00
xen [xen] Wait for and clear XenStore event before receiving data 2015-06-30 17:18:51 +01:00