Re: wortel problems

[Johan Rydberg]

Marcus Brinkmann <address@hidden> wrote:

: physmem uses 0 as the return value for a failed zalloc, so it can not be
: used in physmem anyway.  Apart from that, mapping it into physmem at address
: 0 would prevent any exception from being created when dereferencing a null
: pointer.  The best thing to do is to allocate the page at 0 and remap it
: into physmem at a higher address (ie, add it to the end of available
: memory), so it becomes usable.

Ah, I see.
 
: Is this causing a panic on ppc, or does it just not work?   We can ignore
: any failure (return value l4_nilpag0e) here.

It triggers the following panic in sigma0_get_fpage:

    panic ("%s: sigma0 rejected mapping", __func__);

That's why I just commented it out.  

: > I don't know if something is failing in the communication between
: > wortel and sigma0, but requesting a block of memory with the size
: > if (1 << 31) makes the kernel break into the kernel debugger with
: > the following message:
: > 
: >   map_fpage(from=c0043000, to=c004a000, base=0, sndfp=800001f7, rcvfp=10)
: >   --- KD# map_fpage(): Mapping already exists. ---
: 
: sigma0 patch is supposed to fix that, if it doesn't I don't know why.

I've tried both the CVS version of sigma0, and a patched 0.2 version.
Neither of them work. 

-- 
Johan Rydberg, Free Software Developer, Sweden
http://rtmk.sf.net | http://www.nongnu.org/guss/

Playing Hooverphonic - Sometimes