With this patch the comport are tried to read out from the BIOS Data Area
on x86 machines. The BDA Area are part of the first physical page and may
contain the non-default io ports of the comport.
When used together with 'bender' from the 'morbo' toolchain, even serial PCI
cards (also Intel's AMT Serial Over Line adapter) are detected automatically.
When sigma0 runs on a lower priority than the rest of the threads in the system
it might come to the point that while answering a page fault or I/O memory area
request the timeslice of the caller (core-pager) gets fully consumed. As long as
other threads are still executable and don't block sigma0 won't do progress
anymore, because it runs at the lowest priority. This commit simply sets
sigma0's priority to the highest in the system.
Was: 'sigma0_prio.patch'
In sigma0 normally no answer tag to a request/fault is created. It
simply uses the message tag received with the request. This doesn't work out
when I/O ports are requested. This patch constructs an appropriate answer tag.
Moreover, we have to enable I/O port protection in the kernel configuration.
Was: 'sigma0_ioport.patch'
