Re: [linuxsh-dev] printf

[Greg B. <gb...@po...>]

"Studencki (external) Pawel" wrote:
> 
> Hi,
> 
> I'm still trying to get working kernel 2.3.99 with a RAM disk.
> Boot messages:
> ------------------
> RAMDISK: ext2 filesystem found at block 0
> RAMDISK: Loading 1024 blocks [1 disk] into ram disk... done.
> Freeing initrd memory: 1024k freed
> EXT2-fs warning: mounting unchecked fs, running e2fsck is recommended
> VFS: Mounted root (ext2 filesystem).
> Freeing unused kernel memory: 28k freed
>  --- H E L     <------- it's from "hello world" program in RAM disk

  Ok, so you've got *some* output from a usermode program!

  Any chance you could share the source for this hello world program
so I can see what it was supposed to do?  It's hard for me to comment
on this log by itself.

> 
> ---- that's all...
> 
> Greg, is this the same problem with system calls, which did You and Mitch
> had?

  No.  The symptoms of that problem were a complete and total silence
from user space.  Not a single system call worked.  From your log above
it appears that at least one system call has worked.

> I'm looking for a errors or bugs, but I'm not sure, is this a system call
> problem (so I _have_ to change the  kernel to 2.4.0-test) or this could be a
> problem with initial serial port ( I've changed some things in sh-sci.c,
> because I was getting output like this:
> K<ó{´óK;KCt·L¼·L7´·Lw¿3<³Dt7Ä3KKCË4EUR´´´´EUR<ó Ct;<ûË7KóD3<<<´0fü»»»EUR0´ÿ)
> 
> in function sci_set_termios_cflag
> 
>  - ctrl_out(0x00, SCSCR);  /* TE=0, RE=0, CKE1=0 */
>  + /*ctrl_out(0x00, SCSCR);*/  /* TE=0, RE=0, CKE1=0 */
> 
> and in function sci_set_baud
>  - ctrl_outb(t, SCBRR);
>  + /*ctrl_outb(t, SCBRR);*/

  These sound like a really bad idea in the long run.  You're basically
relying on the boot program to setup the SCI right.

> i can at least read console with these modifications...

  Preventing the kernel from setting the SCSCR register is only
going to result in grief, sooner or later.

  At this point I'd like to recommend again that you upgrade to the
latest kernel in CVS and the appropriate glibc.  It's only going to
get harder for people on this list to help you with older kernels.

> what's more.. when I put some lines like "write(fd,"hello world",15);", than
> I could not even see the output form "printf"...

  Sorry, I don't quite understand your statement.  Are you calling
printf() or write()?

Greg.
-- 
These are my opinions not PPIs.