use the PBVM. This eliminates the implied hardcoding of the
physical address at which the kernel needs to be loaded. Using the
PBVM makes it possible to load the kernel irrespective of the
physical memory organization and allows us to replicate kernel text
on NUMA machines.
While here, reduce the direct-mapped page size to the kernel's
page size so that we can support memory attributes better.
segment so that it's always mapped by the loader.
o Change the alternate fault handlers to account for PBVM. Since
currently the region is handled by the VHPT, no alternate faults
will be generated for it.
ld: locore.o: non-pic code with imm relocation against dynamic
symbol `__gp'
With binutils 2.15, ld(1) defines the implicit/automatic symbol __gp
as a dynamic symbol and thus will now complain when used in a non-PIC
fashion (the immediate relocation used to set the GP register). Resolve
this by defining __gp in the linker script. Make sure __gp is aligned
on a 16-byte boundary.
Note: the 0x200000 magic offset is due to having a 22-bit GP-relative
relocation. The GOT will be accessed with negative offsets from GP.
we can switch to 64M-sized identity mappings and not having to map the
first 64M. This is especially important because the first 1M contains
the VGA frame buffer and is otherwise a legacy memory range. Best to
make as little assumptions about it as possible. Switching to 64M-sized
mappings is important to avoid creating overlapping translations, which
have the side-effect of triggering machine checks. This is currently
what's preventing us to boot on an Intel Tiger 4.
Note that since we currently use 256M-sized identity mappings, we
would reduce the size of the mappings and consequently increase the
TLB pressure. The performance implications of this are minimal if
measurable at all because identify mappings are not our primary
means for memory management.
Also note that there's no guarantee that physical memory exists at
64M. Then again, we didn't had the guarantee when we were loading at
5M. We'll deal with this when it's a problem.
Discussed with: arun@
ia64 only uses relocations with addend, remove the sections specific to
non-addend relocations (.rel.*). Also remove C++ specific sections.
Approved by: re@ (blanket)
into memory. This brings us in line with the other architectures and
more easily allows us to do machine dependent processing on the ELF
file (such as scanning for unwind information).
not work on any real hardware (or fully work on any simulator). Much more
needs to happen before this is actually functional but its nice to see
the FreeBSD copyright message appear in the ia64 simulator.
