[En-Nut-Discussion] ARM MMC Boot Problem

Ole Reinhardt ole.reinhardt at embedded-it.de
Mon Jun 29 18:37:35 CEST 2009

Hi Harald,

> mmcloader seems to work fine too. Otherwise httpserv won't come that
> far, being able to respond to the first one or two HTTP requests, right?

I also had problems using a bootloader. Perhaps at the end this results
from the same problem.

I have a (serial) bootloader, which itself is a NutOS Application linked
to the start of flash. I have my user application linked to offset 64K
into the flash by modifying the startup code and linker script.

My application works fine as long as the .bss and / or .data segment
does not become larger than somewhat around 6000+x bytes. If it grows
larger than this magic threshold my application just freezes if the
bootloader jumps into it. No output at all... If I remove some global
variables so that the bss / data segment is smaler like this threshold
the application works like a charme. So I just have to allocate the
needed ram on the heap instead using global variables.

As I absolutely don't know the reason of this problem I can't tell you
if there is a common reason, but perhaps a starting point for further



|                                                             |
| Embedded-IT                                                 |
|                                                             |
| Ole Reinhardt        Tel. / Fax:        +49 (0)271  7420433 |
| Luisenstraße 29      Mobil:             +49 (0)177  7420433 |
| 57076 Siegen         eMail:    ole.reinhardt at embedded-it.de |
| Germany              Web:         http://www.embedded-it.de |

More information about the En-Nut-Discussion mailing list