- /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.
of config so YOU MUST RECOMPILE CONFIG. Modifying config was the cleanest
solution to integrating this driver into the tree which will become more
obvious in the next commit.
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.
Alphabetize.
Write all i/o functions in sleep so that we don't use anything from
NetBSD.
Restore the correct type of u_int for ports. This saves a whole cycle
per i/o on 486's.
Change `inline' back to __inline to avoid compiler warnings with
-Wreally-all.
Don't implement bdb() unless BDE_DEBUGGER is defined. Declare bdb_exists
outside the function to avoid hundreds of compiler warnings.
Let the compiler pick the register in asms if possible.
Implement ffs() using inline asm(). gcc provides a slightly different
one. It was broken in gcc-2.4.5 but works now. Declaring a correct
version inline ensures getting a correct version. FreeBSD-1.1.5 has
an slow inline version but FreeBSD-2.0 has a library version (which
probably never gets used).
Do inb() and outb() without using %edx for constant ports below 0x100.
Remove casts to the same type in queue functions.
Declare prototypes for everything implemented i386/*.s and also for
everything that is normally implemented as an inline here (I don't
like the current complete dependency on gcc). Ifdef out the prototypes
that are declared elsewhere. THere should be a separate header to
declare things implemented in i386/*.s, but then it would be harder
to override declarations with inlines.
${UII}
with the current default exception (un)mask. There should be no such
processes unless you change the mask. Someday the mask should be
changed to the IEEE default of everything masked. The npx state
gets saved so that it can be checked and this may have the side effect
of fixing a bug that was reported for 1.1.5. (npx exceptions may
sometimes leak across exits and clobber another process. I can't see
how this can happen.)
Get some missing/wrong declarations from headers now that the headers
have them.
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.
Partly support BDE_DEBUGGER. Still broken by conflict with APM. Does
nothing if BDE_DEBUGGER is not defined.
Clean up prototypes and data declarations. Declare most of the segment
functions that are implemented in support.s. Make data private in
machdep.c if possible.
Parenthesize expressions in macros properly!
${Uniformize idempotency ifdef}.
to avoid compiler warnings.
Clean up prototypes: alphabetize; don't use redundant `extern' or
meaningless `extern inline'.
Uniformize idempotency ifdef.
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.
