add rd, pc, #foo - . - 8 -> adr rd, foo
ldr rd, [pc, #foo - . - 8] -> ldr rd, foo
Also, when saving the return address for a function pointer call, use
"mov lr, pc" just before the call unless the return address is somewhere
other than just after the call site.
Finally, a few obvious little micro-optimisations like using LDR directly
rather than ADR followed by LDR, and loading directly into PC rather than
bouncing via R0.
attached to "obio") on the IQ80310 and IQ80321. It makes more sense
to do it this way for this type of system (the goal being to encapsulate
as much information about the board as possible into one file).
to do uncached memory access during VM operations (which can be
quite expensive on some CPUs).
We currently write-back PTEs as soon as they're modified; there is
some room for optimization (to write them back in larger chunks).
For PTEs in the APTE space (i.e. PTEs for pmaps that describe another
process's address space), PTEs must also be evicted from the cache
complete (PTEs in PTE space will be evicted durint a context switch).
counters. These counters do not exist on all CPUs, but where they
do exist, can be used for counting events such as dcache misses that
would otherwise be difficult or impossible to instrument by code
inspection or hardware simulation.
pmc(9) is meant to be a general interface. Initially, the Intel XScale
counters are the only ones supported.
into platform-specific initialization code, giving platform-specific
code control over which free list a given chunk of memory gets put
onto.
Changes are essentially mechanical. Test compiled for all ARM
platforms, test booted on Intel IQ80321 and Shark.
Discussed some time ago on port-arm.
not pre-load the chip's Tx buffer, but instead waits for the Tx Ready
interrupt to transmit the first chunk of data.
* On the IOP310, set COM_HW_NO_TXPRELOAD, rather than COM_HW_TXFIFO_DISABLE.
This solves the "UART hangs" problem on the Npwr in a nicer way (i.e. we
get to use the FIFO, whee). The COM_HW_NO_TXPRELOAD happens to match the
Linux 16550 driver's Tx algorithm, and the "UART hang" was never observed
on the Npwr running Linux.
Eventually, we might want to eliminate the COM_HW_NO_TXPRELOAD, and simply
always use its algorithm. But it should be tested on more 16x50 variants
before we do that.
Kudos to Valeriy Ushakov <uwe@netbsd.org> for pointing out this solution
(which also happens to fix the stray UART interrupt issue on the Krups
Javastation), and to Allen Briggs <briggs@netbsd.org> for experimenting
with various methods of fixing this.
and pte_l2_s_cache_mode. The cache-meaningful bits are different
for these descriptor types on some processor models.
* Add pte_*_cache_mask, corresponding to each above, which has a mask
of the cache-meangful bits, and define those for generic and XScale
MMU classes. Note, the L2_S_CACHE_MASK_xscale definition requires
use of the Extended Small Page L2 descriptor (the "X" bit overlaps
with AP bits otherwise).
Significant cleanup, here, including better PTE bit names.
* Add XScale PTE extensions (ECC enable, write-allocate cache mode).
* Mechanical changes everywhere else to update for new pte.h. While
doing this, two bugs (as a result of typos) were fixed in
arm/arm32/bus_dma.c
evbarm/integrator/int_bus_dma.c
* Don't refer to VA 0, instead refer to a new variable: vector_page
* Delete the old zero_page_*() functions, replacing them with a new
one: vector_page_setprot().
* When manipulating vector page mappings in user pmaps, only do so if
the vector page is below KERNEL_BASE (if it's above KERNEL_BASE, the
vector page is mapped by the kernel pmap).
* Add a new function, arm32_vector_init(), which takes the virtual
address of the vector page (which MUST be valid when the function
is called) and a bitmask of vectors the kernel is going to take
over, and performs all vector page initialization, including setting
the V bit in the CPU Control register ("relocate vectors to high
address"), if necessary.
physical memory start. Garbage-collect some cruft while here.
* Move the kernel up to 0xc0000000, giving a 1G/3G kernel/user split.
* Adjust the Integrator startup code accordingly.
Note that this has been compiled on some systems, cats, IQ80310, IPAQ, netwinder and shark (note that shark's build is currently broken due to other reasons), but only actually run on cats.
Shark doesn't make use of the functionality as I believe there has to be a correlation between OFW and the kernel tables so that calls into OFW work.
