Whether an SoC has the multiprocessing extensions can be read out
from the identification registers, and does not need to be specified
in each board header.
Ref #3445
This commit addresses several multiprocessing issues in base-hw:
* it reworks cross-cpu maintainance work for TLB invalidation by
introducing a generic Inter_processor_work and removes the so
called Cpu_domain_update
* thereby it solves the cross-cpu thread destruction, when the
corresponding thread is active on another cpu (fix#3043)
* it adds the missing TLB shootdown for x86 (fix#3042)
* on ARM it removes the TLB shootdown via IPIs, because this
is not needed on the multiprocessing ARM platforms we support
* it enables the per-cpu initialization of the kernel's cpu
objects, which means those object initialization is executed
by the proper cpu
* it rollbacks prior decision to make multiprocessing an aspect,
but puts back certain 'smp' mechanisms (like cross-cpu lock)
into the generic code base for simplicity reasons
Recent work related to issue 1723 showed that there is potential
to get rid of code duplication in MMU fault handling especially
with regard to ARM cpus.
* Instead of always re-load page-tables when a thread context is switched
only do this when another user PD's thread is the next target,
core-threads are always executed within the last PD's page-table set
* remove the concept of the mode transition
* instead map the exception vector once in bootstrap code into kernel's
memory segment
* when a new page directory is constructed for a user PD, copy over the
top-level kernel segment entries on RISCV and X86, on ARM we use a designated
page directory register for the kernel segment
* transfer the current CPU id from bootstrap to core/kernel in a register
to ease first stack address calculation
* align cpu context member of threads and vms, because of x86 constraints
regarding the stack-pointer loading
* introduce Align_at template for members with alignment constraints
* let the x86 hardware do part of the context saving in ISS, by passing
the thread context into the TSS before leaving to user-land
* use one exception vector for all ARM platforms including Arm_v6
Fix#2091
* introduce new syscall (core-only) to create privileged threads
* take the privilege level of the thread into account
when doing a context switch
* map kernel segment as accessable for privileged code only
Ref #2091
rm_fault.run triggers write on read-only ROM provided by core, which
fails without this patch:
arm - "raised unhandled data abort"
x86 - (silent/invisible) busy loop because write fault gets never resolved
This commit moves the headers residing in `repos/base/include/spec/*/drivers`
to `repos/base/include/drivers/defs` or repos/base/include/drivers/uart`
respectively. The first one contains definitions about board-specific MMIO
iand RAM addresses, or IRQ lines. While the latter contains device driver
code for UART devices. Those definitions are used by driver implementations
in `repos/base-hw`, `repos/os`, and `repos/dde-linux`, which now need to
include them more explicitely.
This work is a step in the direction of reducing 'SPEC' identifiers overall.
Ref #2403
Stefan Kalkowski
Johannes Schlatow
Alexander Boettcher