Messages in this thread | | | Date | Thu, 14 May 1998 23:46:38 +0200 | From | Jens Maurer <> | Subject | Re: 2.1.101 patch to boot on toshiba Portege 660CDT laptop |
| |
Hi,
Torgeir Veimo wrote: > There exist a patch for the 2.0.* series on linux mama that is needed to > get the 2.0.33 series to boot on some laptops when using make bzImage. > > The problem is related to cache coherene problems with addresses above > 0x100000 after enabling the a20 gate.
This issue seems to come up here every two months or so. Note that it concerns bzImage kernels only, zImage kernels should be fine anyway.
> If someone could comment on whether this patch should be standard or not > it would be appreciated. It would be sad if we needed special patched > kernels to boot on commonplace laptop computers.
I wrote the original ("old") patch you attached to your mail (with help from Hans Lermen and Werner Almesberger). However, I have second-hand knowledge that this patch causes problems on a few computers which work fine without the patch. (Note to all people staring on the 0x2000 words = 16 KB thing: For the Toshiba Tecra 710CDT, on which I developed the patch, reading only two bytes instead of 16 KB at that point was enough to get it to boot.)
I would be very interested in getting to know someone who does have problems with this "old" patch on his or her machine.
In addition to that, Alan Cox correctly pointed out a few months ago that the patch is rather unclean. Therefore, I developed a nicer patch (attached below) which checks if we are on a 486 or better and if so, disables the caches around the A20 toggle. This is actually against 2.1.58, but seems to patch and compile cleanly for 2.1.101 as well. Note that I no longer have access to such a broken laptop and therefore need YOUR help to get it tested.
If something like this ever goes into a production kernel, this patch certainly is a better candidate than the "old" one. However, before that happens, I do need positive and negative feedback. I am especially interested in reports from people who had problems with my "old" patch.
Thanks, Jens [unhandled content-type:application/octet-stream] | |