instead of having application processors spin in mpshutdown()
with mmu on, and be subject to reboot() overriding kernel text
and modifying page tables, park the application processors in
rebootcode idle loop with the mmu off.
this driver makes regions of physical memory accessible as a disk.
to use it, ramdiskinit() has to be called before confinit(), so
that conf.mem[] banks can be reserved. currently, only pc and pc64
kernel use it, but otherwise the implementation is portable.
ramdisks are not zeroed when allocated, so that the contents are
preserved across warm reboots.
to not waste memory, physical segments do not allocate Page structures
or populate the segment pte's anymore. theres also a new SG_CHACHED
attribute.
introducing the PFPU structue which allows the machine specific
code some flexibility on how to handle the FPU process state.
for example, in the pc and pc64 kernel, the FPsave structure is
arround 512 bytes. with avx512, it could grow up to 2K. instead
of embedding that into the Proc strucutre, it is more effective
to allocate it on first use of the fpu, as most processes do not
use simd or floating point in the first place. also, the FPsave
structure has special 16 byte alignment constraint, which further
favours dynamic allocation.
this gets rid of the memmoves in pc/pc64 kernels for the aligment.
there is also devproc, which is now checking if the fpsave area
is actually valid before reading it, avoiding debuggers to see
garbage data.
the Notsave structure is gone now, as it was not used on any
machine.
introduce cpushutdown() function that does the common
operation of initiating shutdown, returning once all
cpu's got the message and are about to shutdown. this
avoids duplicated code which isnt really machine specific.
automatic reboot on panic only when *debug= is not set
and the machine is a cpu server or has no display,
otherwise just hang.
on vmware, loading a new kernel sometimes reboots when
wiggling the mouse. disabling keyboard and mouse on
shutdown fixes the issue.
make sure ps2 mouse is disabled on init, will get re-enabled
in i8042auxenable().
keyboard isnt special anymore, we can just use the devreset
entry point in the device to do the keyboard initialization,
so kbdinit()/kbdenable() are not needed anymore.
there are no kernels currently that do page coloring,
so the only use of cachectl[] is flushing the icache
(on arm and ppc).
on pc64, cachectl consumes 32 bytes in each page resulting
in over 200 megabytes of overhead for 32gb of ram with 4K
pages.
this change removes cachectl[] and adds txtflush ulong
that is set to ~0 by pio() to instruct putmmu() to flush
the icache.
rampage() cannot be used after meminit(), so test for
conf.mem[0].npage != 0 and use xalloc()/mallocalign()
instead. this allows us to use vmap() early before
mmuinit() which is needed for bootscreeninit() and
acpi.
to get memory for page tables, pc64 needs a lowraminit().
with EFI, the RSDT pointer is passed in *acpi= parameter
from the efi loader. as the RSDT is ususally at the end of
the physical address space (and not to be found in
bios areas), we cannot KMAP() it so we need to vmap().
as we do system reset and reboot only from boot processor cpu0 now,
theres no need for active.rebooting conditional variable.
mpshutdown() will unconditionally park application processors and
and cpu0 boots the new kernel or calls mpshutdown() causing system
reset.
the heuristics that limits kernel memory on a cpu server to
a fixed amout (64MB + size for page tables) makes using devdraw
impractical.
if *imagemaxmb= is specified, we can assume that the draw device
will be used so we want to get a reasonable amount (30% default)
of kernel memory.
the tag-word is not compatible between x87 and sse, have to convert
properly for emulation to work.
we now copy fp state across fork (again!) to preserve FCW and MXCSR
registers. this might not be neccesary as we could probably just
get the current value for the curren process and avoid the fpsave()
call, but become conservative again.
we now always use the new FXSAVE format in FPsave structure and fpregs
file, converting back and forth in fpx87save() and fpx87restore().
document that fprestore() is a destructive operation now.
change fp register definition in libmach and adapt fpr() acid funciton.
avoid unneccesary copy of fpstate and fpsave in sysfork(). functions
including syscalls do not preserve the fp registers and copying fpstate
from the current process would mean we had to fpsave(&up->fpsave); first.
simply not doing it, new process starts in FPinit state.
the fpenv() instruction stores in x87 format, using mathstate()
would interpret fpsave as FPssestate in case it was enabled!
instead, pass the status word and fppc explicitely to mathnote()
in matherror().
get rid of m->fpsavealign buffer, as we can just use FPssesave struct
which has enougth padding so rounding up base pointer will not overflow.
