Using a real harddisk

[w_schmidt at ...181...]

Hi,

Thanks for the answer.

>> I want to access files from a harddisk using a block cache. The partition
>> would be /sda7/test in ext2 format. (and for example file1.txt) I tried 
>> to
>> start nova directly form disc - works with mouse & keyboard now.

> Assuming your machine is an x86 derivative and supports AHCI, you could
> use Genode's AHCI driver, which will expose a block sesssion (see:
> os/src/drivers/ahci/README). In order to access the partitions on your
> disk, a server called 'part_blk' is required (see:
> os/src/server/part_blk/README for its configuration). So, you would have
> to remove 'ram_blk' and add 'ahci_drv', 'part_blk' (routed to
> 'ahci_drv'), adjust 'rump_fs' to be routed to 'part_blk' partition 7.

I have 2 possible machines with AHCI and AMD64/Intel64.

Maybe I understand it completly wrong, but in the AHCI description there is 
a part with
"On real hardware and on kernels taking advantage of I/O APICs (namely NOVA 
and
Fiasco.OC) we still lack support for ACPI parsing and thus for interrupts,
leading to a non-working driver." ( 
https://github.com/genodelabs/genode/blob/master/repos/os/src/drivers/ahci/README 
 )

Doesn't that mean that the AHCI driver won't work with nova or real hard 
drive? That sentence is one of the reasons why I ask.
If nova /real hardware does not work like mentioned in the readme, is there 
another way to load from disc? Or should another kernel (?L4k?) do the 
trick?

> The cache is greedy and tries to get as much memory from its parent as
> possible. By the way, rump has a build in block cache also.

Yes I have seen that in the rump description there stood something that the 
server will use most of the RAM for cache.

I thought I coudl do the following:
Give the block cache e.g. 16MB RAM.
Give the Rump Server 6 MB, and load different 4 MB files. I thought that by 
loading the second file the first one will get out of the Rump cache but 
loaded by the block cache.

I have seen that the framebuffer seems to have a sort of multiplexer. Is 
something similiar available for filesystems?

>> RAM...
> I think the author just did not want to calculate the amount of RAM
> required for the test program.

O.K.

>> Afterwards i included in the set build_components section 
>> server/blk_cache
>> (after drivers/timer) and entered as boot module blk_cache.  Is this the
>> correct way of including the cache?

> Yes it is!

Good. :-)

>> The result of this was that I got an output with: [init -> blk_cache]
>> updating quota for SIGNAL session, an init rump_fs upgrade quota output 
>> and
>> afterwards and a long stop after init->rump_fs Backend::Backend() Backend
>> blk_size 512 Afterwards the script stopped with   Test execution timeout.
>> with error 254) What could I have done wrong with the configuration of 
>> this
>> scenario?

>Ok, I will try to reproduce the behavior.

Thanks, that would be interesting. If it helps I can upload my configuration 
file somewhere?

I think I can try file access and AHCI first on friday (ATM a lot of work, 
I'm interested at genode because of part time study)

Thanks & Best regards,
Wolfgang Schmidt