TODO

Fri, 12 Apr 2013 12:34:32 +0100

author
Philip Pemberton <philpem@philpem.me.uk>
date
Fri, 12 Apr 2013 12:34:32 +0100
branch
experimental_memory_mapper_v2
changeset 140
1e4c45b144c4
parent 131
21c770fcee50
permissions
-rw-r--r--

Fix read-after-write logic

In some cases (notably reading from a page after having written to it), the
mapper may change the pagestate from "accessed and written" ("dirty"; PS0,PS1)
to "accessed but not written" (clean; PS1,!PS0). This should never, ever, EVER
happen. Once a page is dirty, it remains so until the 68k clears the DIRTY
bit.

Once again, this wonderful bit of logic was missing from the TRM.

philpem@131 1 TODO -- things to check
philpem@131 2
philpem@131 3 * Realtime clock
philpem@131 4 * WD2010 command handler logic
philpem@131 5 * Disabling page write protect logic allows userspace to run up but HDD won't mount
philpem@131 6 * DMA Page Fault issues (see wd2010.c and test code)