raw L4Task: Flash Access & Variable

ba_f ba_f at rbg.informatik.tu-darmstadt.de
Wed Oct 15 15:04:12 CEST 2014

Hello and thank u so far,

>> Adam wrote:
> It is possible. But of course there needs to be a driver for your flash
> and a filesystem (if needed). And there's none.
> There's a tmpfs, i.e. a filesystem that can store files, however, not
> across reboots. Maybe that helps you already?

Yes, volatile storage would do the trick.

Unfortunately, i need some help here, too. :(

I've found a post from Adam, concerning tmpfs:

I did all it says, and of course edited anything to my concerns. But my 
App fails to write at /tmp.
fopen("/tmp/file", "wb") == NULL

Maybe i do not place the fstab-file correct.
Right now, fstab is located in the MODULE_SEARCH_PATH. But building the 
image does also work if there is no such file.
Running the image, there are no complaints about a missing fstab.
Is this correct behaviour?

I also added fstab to my modules.list, without success.

Is there another way to check if fstab is loaded correctly, besides 
using fopen().

Here my files (shorted):

# fstab
/     /tmp    tmpfs defaults

# modules.list
entry app-cfg
kernel fiasco -serial_esc
roottask moe rom/app.cfg
module l4re
module ned
module app.cfg
module fstab
module libmount.so
module libl4revfs-fs-tmpfs.so

# app.cfg
ld:start( "rom/app", { FSTAB_FILE = "rom/fstab" });

# Makefile
REQUIRES_LIBS   = libmount libl4revfs-fs-tmpfs

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