Help needed: clearing the 68020 cache.
Ole Agesen
agesen at daimi.dk
Thu Jul 6 19:26:13 AEST 1989
Help needed....
The MC68020 incorporates an on-chip cache memory. The cache is used to
store the instruction stream prefetch accesses from the main memory. I'm
currently implementing a kind of incremental linking implying the need to
write self-modifying code. Therefore, I have to clear the cache upon a
modification of the code. According to the MC68020 User's Manual the cache
is cleared by issuing a MOVEC instruction (move control register).
However, this is a privileged instruction (requiring supervisor state).
Can anyone tell me how to clear the cache?
Can I get supervisor privileges for a user process?
Is there a kernel operation clearing the cache?
Can I easily create a modified kernel with the desired operation?
Other (more) realistic possibilities?
(We are using Unix 4.0 on sun 3/50).
Thanks in advance!
Ole Agesen
More information about the Comp.sys.sun
mailing list