to "screen" node directly. The problem is that by default OF on some (all?)
Macs either doesn't provide "/chosen/stdout" or redirects it somewhere,
unless you boot in manual mode via CMD-ALT-O-F. It's nice to see normal
FreeBSD boot output instead of blank gray screen.
make it memory-coherency enforced (PTE_M). This is required for SMP
to work.
o Serialize tlbie operations and implement the tlbie operation in a
function called tlbie(). Hardware can end up in a live-lock if
between the tlbsync and subsequent sync on one processor another
processor executes a tlbie or tlbsync.
o Eliminate the following defines:
TLBIE, TLBSYNC, SYNC and EIEIO
Use either inline assembly statements or inline functions defined
in <machine/cpufunc.h>
caches if not yet enabed. This is required for coherency and
atomic operations to work, not to mention performance. We use the
L2 and L3 cache settings of the BSP to configure the APs caches.
Can't be bad.
Program NAP and not DOZE. DOZE is present only on earlier CPUs
and the bit is reserved on the MPC7441 & MPC7451. NAP will do
bus snooping to keep caches coherent.
Program the PIR with the cpuid. This may not be necessary...
We're only returning a 32-bit counter.
o In decr_intr(), manually perform LICM, so that we don't test
a loop invariant condition inside a loop.
o Include <machine/smp.h>
volatile so that the compiler won't perform CSE. For SMP,
this may result in us accessing the wrong PCPU and as such
results in a bogus curthread value.
Note that getting curthread is not quite MP-safe in the sense
that it requires two instructions that aren't performed
atomically. The first instruction gets the address of the PCPU
structure and the second instruction dereferences that pointer
to get curthread. If a thread is switched-out in between these
instructions and switched-in on a different CPU, we still get
the wrong curthread.
common PowerPC code when all we want to achieve is to enable
external interrupts. We can set PSL_RI at any time before we
allow interrupts and/or exceptions, so move it to the AIM
specific initialization and do it when we also set PSL_ME
(machine check enable).
configuring the L2 cache on the BSP. Nor the L3 cache. We
merely print the settings.
Save the L2 and L3 cache configuration in global values so
that we know how to configure the cache on APs.
- Allocate thread0.td_kstack in pmap_bootstrap(), provide guard page
- Switch to thread0.td_kstack as soon as possible i.e. right after return
from e500_init() and before mi_startup() happens
- Clean up temp stack area
- Other minor cosmetics in machdep.c
Obtained from: Semihalf
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
As clearly mentioned on the mailing lists, there is a list of drivers
that have not been ported to the MPSAFE TTY layer yet. Remove them from
the kernel configuration files. This means people can now still use
these drivers if they explicitly put them in their kernel configuration
file, which is good.
People should keep in mind that after August 10, these drivers will not
work anymore. Even though owners of the hardware are capable of getting
these drivers working again, I will see if I can at least get them to a
compilable state (if time permits).
Now that st_rdev is being automatically generated by the kernel, there
is no need to define static major/minor numbers for the iodev and
memdev. We still need the minor numbers for the memdev, however, to
distinguish between /dev/mem and /dev/kmem.
Approved by: philip (mentor)
o The function is defined unconditionally but depends on SPR_SVR,
which is defined conditionally.
o spr.h defines mfspr() and mtspr(), which is no worse to use.
by the parent for interrupt resources. This corrects parsing of
the interrupts property.
With parsing of the property fixed, add all interrupts to the
resource list. Bump the max. number of interrupts from 5 to 6
as scc(4) attached to macio(4) has 6 interrupts (3 per channel).
Submitted by: Nathan Whitehorn <nathanw@uchicago.edu>
