PROBLEMS BOOTING KERNEL ON EMBEDDED PROCESSOR MBX821

PROBLEMS BOOTING KERNEL ON EMBEDDED PROCESSOR MBX821

[Neil Blackwood]

        I have just downloaded the 2.2.0pre6 kernel for MBX8xx processors
from
the embedded directory of linuxppc.cs.nmt.edu.

We are running it on a MXX821-004A development board.

Unfortunately we seem to have a problem during the booting of the kernel.

The messages

                        iack = -1

and
                        irq = 7

are displayed continuously.

We have managed to track down the iack message in the kernel source.

In directory

linux/arch/ppc/kernel

in File

ppc8xx_pic.c

In function

mbx_i8259_action()
is the code

                int irq;

                irq = (inl(0x508)>>24)&0xff;
                if (irq!= 0xff)printk("iack 5d\n", irq);

We think this is inconsistent if the value of irq is printed out as -1.



We have previously run a 2.1 version of the kernel successfully. Do you have
any ideas to solve the problem?


I am also looking at including floating point libraries into the kernel.
Does anything currently exist?



                                Neil Blackwood

ps Is this type of enquiry suitable for this mailing list or should I use
USERS.

pps I am completely new to LINUX and operating systems in general, so my
current level of understanding is very low.
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Re: PROBLEMS BOOTING KERNEL ON EMBEDDED PROCESSOR MBX821

[Geert Uytterhoeven]

On Thu, 5 Aug 1999, Neil Blackwood wrote:
>         I have just downloaded the 2.2.0pre6 kernel for MBX8xx processors
> from
> the embedded directory of linuxppc.cs.nmt.edu.
> We are running it on a MXX821-004A development board.
> Unfortunately we seem to have a problem during the booting of the kernel.
> The messages
> 
>                         iack = -1
> 
> and
>                         irq = 7
> 
> are displayed continuously.
> 
> We have managed to track down the iack message in the kernel source.
> In directory
> linux/arch/ppc/kernel
> in File
> ppc8xx_pic.c
> In function
> 
> mbx_i8259_action()
> is the code
> 
>                 int irq;
> 
>                 irq = (inl(0x508)>>24)&0xff;
>                 if (irq!= 0xff)printk("iack 5d\n", irq);
> 
> We think this is inconsistent if the value of irq is printed out as -1.

The first thing in my mind that gets triggered by this is unsigned vs. signed
chars. On most systems, `char' defaults to `signed char', but on PPC it
defaults to `unsigned char'. Either behavior complies with the C standard.
But I don't see where it gets wrong here :-(

> ps Is this type of enquiry suitable for this mailing list or should I use
> USERS.

IMHO this is the correct list.

Greetings,

						Geert

--
Geert Uytterhoeven                     Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP}  http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium


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