L4-Linux worked on 486!

[Michael Hohmuth]

edmundo at rano.demon.co.uk writes:

> L4-Linux is running quite nicely for me now, but I can still crash it
> by doing cksum /usr/bin/* over CVS. It dies after saying "irq still
> active". (To get that message I'm using the patch that Michael Hohmuth
> posted to the list on July 25.)
> 
> I think I may have found a bug in the SANITY code in
> linux22/arch/l4-i386/kernel/irq.c, by the way. [...]

> This is what I did to linux22/arch/l4-i386/kernel/irq.c:
> 
> In timer_irq_thread(), I moved
> 
> #ifdef SANITY
>       irqs_in_progress &= ~(1 << TIMER_IRQ);
> #endif
> 
> from its present position just before the call to
> l4_i386_ipc_receive() to just before the call to
> execute_bottom_halves(). This got rid of the "irq active" messages
> which I think are spurious.
> 
> Sorry for the lack of patch but I've rather lost control of the
> versions of that file ...

My patch you mentioned already contains a similar change...  Can you
send my (in private email) the output of "cvs diff irq.c" (before you
do "cvs update")?

Anyway, I've now checked in my sanity-checking changes in
linux22/arch/l4-i386/kernel/irq.c.  I suggest you use that version for 
testing.

> What I have been doing is telling GDB "symbol-file .../vmlinux" to
> inspect what's happening in Linux, then "symbol-file .../kernel.image"
> to go back to inspecting Fiasco. There's probably some way of defining
> macros to make that switching a bit easier. I don't know if GDB could
> use both sets of symbols at the same time.

Me neither.

> (This is a bit off topic, but does anyone know a better solution to
> this one? I tell GDB "p spong" and get a value that is totally wrong.
> This is because the variable has been optimised into a register. So to
> find out its value I use "disassemble" and "info registers". Is there
> a quicker way?)

Unfortunately, no, AFAIK.

Michael
-- 
hohmuth at innocent.com, hohmuth at sax.de
http://www.sax.de/~hohmuth/