Re: spontaneous reboot only once after power-up

Izumi Tsutsui <[email protected]>
Newsgroups gmane.os.netbsd.ports.sh3,gmane.os.netbsd.ports.dreamcast
Message-ID <[email protected]>
In article <[email protected]>
[email protected] wrote:

> I happen to try following change and the problem disappear.
> Here, we are clearing the TLB.  The original code clears TLB
> via address array, and new code does it via data array 1.

I just take a look at SH4 programming manual, but
I guess if you use UTLB data array 1 to invalidate TLB entries
there are follow problems:
(1) it does not clear VPN
(2) it might break other bits (cacheable, writethrough etc.)

BTW, there is an errata about TLB usage for SH3:
http://www.hitachisemiconductor.com/sic/resource/japan/eng/pdf/mpumcu/ms/tnsh7291ae.pdf
According to this doc, it's better to wrote 0xf0000000 to VPN on
invalidating TLB entries to avoid an exception on TLB
(which might cause another bug of SH3).

I think SH4 does not have this bug, but I guess it's still better
to use 0xf0000000 for VPN on invalidating TLB via address array.
---
Izumi Tsutsui
[email protected]
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.