1) i586_bcopy() problem
There have been a number of reports that the syscons doesn't work
properly if i586_bcopy() is enabled.
The problem prevented users from installing 2.2(.1)-RELEASE. The
symptom is that the system looks frozen during device probe or just
before the main installation menu. The workaround was to specify the
flag 0x01 to the npx device so that i586_bcopy() is disabled.
The patch forces the syscons to call generic_bcopy() when copying
to/from the video memory, even if CPU is Pentium and i586_bcopy() is
enabled. i586_bcopy() is still called for copy operations between
non-video memory regions.
PR: kern/2277, kern/3066, kern/3107, kern/3134
2) video mode parameter table problem
The syscons reads and uses the video mode parameter table provided by
the VGA BIOS to set VGA registers when changing video mode and
modifying font data. It appears that in some VGA BIOSes the table is
not ordered as the syscons expects, and this leads to screen
corruption.
The problem prevented users from installing 2.2(.1)-RELEASE. The
symptom is the corrupt screen or strange vertical lines soon after the
kernel is loaded into memory (just after the kernel decompression).
The patch performs simplistic test and if it fails, set video_mode_ptr
to NULL so that the video mode switching won't happen.
This is an interim kludge. There should be a better way to deal with
the problem.
PR: kern/2498, conf/2775, conf/3354
Reviewed by: sos
Tested by: PR originators (not all of them, though)
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