[rng] Use fixed-point calculations for min-entropy quantities
We currently perform various min-entropy calculations using build-time
floating-point arithmetic. No floating-point code ends up in the
final binary, since the results are eventually converted to integers
and asserted to be compile-time constants.
Though this mechanism is undoubtedly cute, it inhibits us from using
"-mno-sse" to prevent the use of SSE registers by the compiler.
Fix by using fixed-point arithmetic instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Move most arch/i386 files to arch/x86, and adjust the contents of the
Makefiles and the include/bits/*.h headers to reflect the new
locations.
This patch makes no substantive code changes, as can be seen using a
rename-aware diff (e.g. "git show -M5").
This patch does not make the pcbios platform functional for x86_64; it
merely allows it to compile without errors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The RTC-based entropy source uses the nanosecond-scale CPU TSC to
measure the time between two 1kHz interrupts generated by the CMOS
RTC. In a physical machine these clocks are driven from independent
crystals, resulting in some observable clock drift. In a virtual
machine, the CMOS RTC is typically emulated using host-OS
constructions such as SIGALRM.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown