having the memconf() (*e820=) last clutters the screen.
do it first, so we can read *acpi= and *bootscreen=
prints.
we want to continue using tftp even when the /cfg/pxe/$ether
file is not found. only when we detect no pxe/dhcp session,
then we switch to local filesystem (non-network boot).
to make it possible to mark the bootscreen framebuffer
as write combining in early initialization, mtrr() is
changed not not to error() but to return an error string.
as bootscreen() is used before multiprocessor initialization,
we have to synchronize the mtrr's for every processor as
it comes online. for this, a new mtrrsync() function is
provided that is called from cpuidentify() if mtrr support
is indicated.
the boot processor runs mtrrsync() which snarfs the
registers. later, mtrrsync() is run again from the
application processors which apply the values from the
boot processor.
checkmtrr() from mp.c was removed as its task is also
done by mtrrsync() now.
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().
to get the right data size of a file, the revlog needs to have been
opened and the metaheader parsed. as an optimization, we used to
open revlog only on the first read resulting revlogs with metaheaders
having the wrong size returned by fstat() until the first read().
tar relies on fstat() giving the correct file size, so just open
the revlog on open. reading directories can still yield the wrong
size but it is not that critical.
there was a memory corruption bug caused by us enabling the
ps2mouseputc() handler *before* initializing packetsize.
once we enabled the handler, mouse interrupts could come
in and advance the packet buffer index (nb) beyond the
buffer boundaries.
as ps2mouseputc() only checked for ++nb == packetsize, once
nb was advanced beyond the packetsize, it would continue writing
beyond the buffer and corrupt memory with each mouse packet byte.
solution is to initialize packetsize *before* enabling the
handler, and also do a >= check in ps2mouseputc() in case the
packetsize gets changed to a smaller value at runtime.
we used to set RD flag in requests unconditionally, which
is fine by the standard but some dns server administrators
seem to use it as a denial of service indicator (for ther
non recursive authoritative nameservers) and ignore the
request.
so only set the RD flag when talking to local dns servers.
alexchandel got the kernel to crash with divide error
on qemu 2.1.2/macosx at this location. probably
caused by perfticks()/tsc being wrong or accounttime()
not having been called yet from timer interrupt yet for
some reason.
