Release 17.05, base-hw, environment ROM session denied error

Norman Feske norman.feske at ...1...
Tue Jun 13 10:26:57 CEST 2017

Hi Bob,

> "[init] Error: ctrl_module: environment ROM session denied
> (label="ctrl_module",
> ram_quota=6144, cap_quota=3, diag=0) "
> What is this message telling me?

traditionally, init created the initial sessions (aka environment
sessions) of its children on the children's behalf without considering
any child-specific routing. I.e., a child's PD session, CPU session, the
ROM session with the executable binary, the ROM session with the dynamic
linker were created by init directly via 'Connection' objects.
Therefore, there was no need to route those sessions explicitly in the

With version 16.11 and 17.02 [1], we revised the child-creation
procedure. Now, the environment sessions are subjected to the routing
rules as dictated by init's configuration.


In short, your routing rules for the "ctrl_module" lack a valid route
for the executable binary.

> Also, further down the log is the following output:
>    init -> gpio_drv] resource_request: ram_quota=0,
> cap_quota=4                  
>    [init -> gpio_drv] used before freeing
> emergency=276K                          
>    [init -> gpio_drv] used after freeing emergency=260K   
> I believe these are a result of the gpio server setting up a session
> through the session interface.

The 'gpio_drv' component runs out of its capability quota and politely
asks its parent (init) for more (cap_quota=4). Capability quotas are new
in version 17.05 and are described at [2].


You may try to specify a 'caps=200' attribute to the start node of the
corresponding component.


Dr.-Ing. Norman Feske
Genode Labs ·

Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden
Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

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