shifting. Also correct the original code as Garrett noticed it in mail.
Leave the mishandled code in to use it later if future versions of gcc
are correct. The code was part of the calibrate_cyclecounter routine to
get the speed of the pentium chip.
- /sys/i386/i386/swapgeneric.c is just plain broke. But fear not, for I
have unbroken it. One thing that swapgeneric.c does is walk through the
list of configured devices searching for a boot device. The only easy
way to accomplish this in 2.0 is to use Garret Wollman's kern_devconf
stuff. *BUT*, the head of the kern_devconf linked list (dc_list) is declared
static in /sys/kern/kern_devconf.c. This means that swapgeneric.c can't
see it at link time. I had to remove the 'static' keyword to get around
this little problem. I hope this doesn't break anything anywhere.
*Furthermore,* there's a small matter of making the call to setconf()
in swapgeneric.c disappear when 'config kernel swap generic' isn't used.
You could change /sbin/config to create a dummy setconf() function in
swapkernel.c, but that seems messy somehow. (It's also someting of an
'it isn't broken, why are you fixing it' situation.) My solution was to
do what the NetBSD people did and put an #ifdef GENERIC around the call
to setconf(). If your kernel is called GENERIC or you define 'options
GENERIC,' then you can use 'config kernel swap generic' and it'll work.
That aside, the upshot is that: a) swapgeneric.c actually works, and
and b) the -a boot flag now works as well. If you boot with -a, as in
"Boot: wd(0,a)/kernel -a" you will be presented with a 'root device?'
prompt after the autoconfig phase, at which point you can specify what
device you want mounted as root. Regrettably, you can't specify an NFS
filesystem. Yet. Three files are affected: /sys/i386/i386/swapgeneric.c,
/sys/i386/i386/autoconf.c and /sys/kern/kern_devconf.c.
Submitted by: wpaul
Move definition of `stat_imask' to clock.c.
clock.c:
Rename `rtcmask' to `stat_imask' and export it. Rename `clkmask' to
`clk_imask' for consistency.
Only calculate TIMER_DIV(hz) once.
Merge debugging and "garbage" code to produce debugging code and format the
output better.
Make writertc() static inline and use it everywhere. Now all accesses to
the clock registers go through rtcin() and writertc().
Move rtc initialization to cpu_initclocks().
Merge enablertclock() with cpu_initclocks() and remove enablertclock().
The extra entry point was just a leftover from 1.1.5.
Fix single-stepping of emulated FPU instructions.
Don't panic if an FPU instruction is attempted but there is no FPU
and no FPU emulator is configured.
Keep track of interrupt nesting level. It is normally 0
for syscalls and traps, but is fudged to 1 for their exit
processing in case they metamorphose into an interrupt
handler.
i386/genassym.c;
Remove support for the obsolete pcb_iml and pcb_cmap2.
Add support for pcb_inl.
i386/swtch.s:
Fudge the interrupt nesting level across context switches and in
the idle loop so that the work for preemptive context switches
gets counted as interrupt time, the work for voluntary context
switches gets counted mostly as system time (the part when
curproc == 0 gets counted as interrupt time), and only truly idle
time gets counted as idle time.
Remove obsolete support (commented out and otherwise) for pcb_iml.
Load curpcb just before curproc instead of just after so that
curpcb is always valid if curproc is. A few more changes like
this may fix tracing through context switches.
Remove obsolete function swtch_to_inactive().
include/cpu.h:
Use the new interrupt nesting level variable to implement a
non-fake CLF_INTR() so that accounting for the interrupt state
works.
You can use top, iostat or (best) an up to date systat to see
interrupt overheads. I see the expected huge interrupt overheads
for ISA devices (on a 486DX/33, about 55% for an IDE drive
transferring 1250K/sec and the same for a WD8013EBT network card
transferring 1100K/sec). The huge interrupt overheads for serial
devices are unfortunately normally invisible.
include/pcb.h:
Remove the obsolete pcb_iml and pcb_cmap2. Replace them by
padding to preserve binary compatibility.
Use part of the new padding for pcb_inl.
isa/icu.s:
isa/vector.s:
Keep track of interrupt nesting level.
comconsole will behave as expected. The true problem should be fixed
instead, Bruce' comment for this:
>Anyway, i found the reason for my problems: somehow, ICRNL isn't in
>effect at `userconfig' time (but only for comconsole?), hence only
ICRNL doesn't apply to cngetc(). cnputc() unconditionally does the
equivalent of ONLCR; perhaps cngetc() should unconditionally do the
equivalent of ICRNL. Ddb must be checking for CR. Userconfig only
checks for NL. Userconfig works with syscons because pccngetc()
does the conversion. This is probably the wrong place to do it.
was supposed to have already been made, but got botched somewhere.
Don't clobber the last page of memory (where the message buffer is). Some
BIOS don't gratuitously wipe it out on reboot.
the following.
Move declarations to and from <machine/segments.h>. Make segment stuff
static if possible.
Remove unused (although initialized) global variables _default_ldt,
currentldt, _gsel_tss (rename the latter to the auto variable
gtel_tss).
Use "correct" and consistent types for interrupt handlers.
Remove a mailing address from the code.
Fix type mismatches found by adding prototypes.
get truncated to LONG_MAX. Don't lobotomize the merged library source.
Make all private data static.
Use int_parms for the i/o "address" since the "address" is really a number
and is represented as an int.
Add command `flags' to allow changing device flags.
Fix scrolling of device listing. Only scrolling of the current devtab
was controlled. Reprint the header after scrolling.
Rename commands and change strings to match their config(8) keywords:
io -> port
IOaddr -> port
mem -> iomem (abbreviation is io :-()
MemAddr -> iomem
case changes
Don't use NULL for ASCII NUL.
Call strtoul() with base 0 for both numbers and addresses so that input
is consistent and hex and octal can be used for numbers.
Fix entry of irq number. Check the range at no extra cost. It wasn't
possible to enter irq -1.
Format device listing better. Large numbers (such as 0xffffffff for the
GENERIC lpt0 port) messed up the formatting.
Show the unit number in the device listing. Comment about the fields
that aren't shown.
Somebody should make a mib variable for it.
Just now it is pointless to dump the kernel, since we have nothing which
can read the dump.
Furthermore is should never be the default to dump.
options DODUMP
will enable dumps.
for all reasonable HZ's. HZ > 1000 doesn't work because of sloppy
conversions in hzto() (division by (tick / 1000) == 0). This was
fixed in 1.1.5.
Eliminate some extern declarations by including the appropriate header
files that now contain appropriate declarations.
doesn't have to calculate it every call.
Rename `timer0_prescale' to `timer0_prescaler_count' and maintain it
correctly. Previously we lost a few 8253 cycles for every "prescaled"
clock interrupt, and the lossage grows rapidly at 16 KHz. Now we
only lose a few cycles for every standard clock interrupt.
Rename `*_divisor' to `*_max_count'.
Do the calculation of TIMER_DIV(rate) only once instead of 3 times each
time the rate is changed.
Don't allow preposterously large interrupt rates. Bug fixes elsewhere
should allow the system to survive rates that saturate the system, however.
Clean up declarations.
Include <machine/clock.h> to check our own declarations.
outside the critical region.
Make it work with 2.0. It wasn't designed to be called at splclock().
Make it work with prescaling. The overflow threshold was bogus.
Make it work for any HZ. Side effect of fixing prescaling.
Speed it up. Allocate registers better. Reduce multiplication and
division to multiplication and a shift. Speed is now 5-6 usec on a
486DX/33, was about 3 usec more.
Optimize for the non-pentium case. The pentium code got moved around
a bit and hasn't been tested.
Change #include's to 2.0 style.
