Also in the ARM32_PMAP_NEW case, reclaim the USPACE-bytes of wasted space
at the top of the user address that hasn't been needed for a very very
long time.
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).
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.
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.
