Hello
Thank you for your help so far. I still have some unclarity about the DMA in
seL4 and maybe you could help me again:
With the seL4DTBHardware connection I created the following device frames,
given paddr: 0x4a100000, size: 0x4000
device frame/untyped, paddr = 0x4a100000, size = 12 bits
device frame/untyped, paddr = 0x4a101000, size = 12 bits
device frame/untyped, paddr = 0x4a102000, size = 12 bits
device frame/untyped, paddr = 0x4a103000, size = 12 bits
If I am not mistaken these should already be allocated dma memory buffer and
thus have a virtual address as well.
So I try to retrieve the VADDR from the first device frame by invoking the
following runtime API:
ps_io_mapper_t *mapper = &io_ops->io_mapper;
uintptr_t vaddr = (uintptr_t) mapper->io_map_fn(mapper->cookie,
0x4a100000, 0x4000,0, PS_MEM_NORMAL);
Afterwards vaddr is a valid pointer (here: 0xab4000).
However, by using the next runtime API I always receive a NULL pointer:
uintptr_t paddr = camkes_dma_get_paddr(vaddr);
Am I missing a step or is something else going wrong?
Sincerely,
Benjamin
________________________________
Von: Lee, Damon (Data61, Kensington NSW) [[email protected]]
Gesendet: Mittwoch, 19. Juni 2019 07:45
An: KAP Benjamin; [email protected]
Betreff: Re: Beaglebone Black: failed to find device frame
Hi Benjamin,
1) Both are necessary. The low_level_init function in the PicoServer component
is paired with the Ethdriver component. This reads in the MAC address that is
given to each client of the Ethdriver component.
The low_level_init function in the libethdrivers is also paired with the
Ethdriver component but it reads in the MAC address assigned to the device.
The reason why we have both is because the Ethdriver component was designed to
have multiple clients connected to it, i.e. multiplexing a Ethernet card for
multiple clients. This is an issue that we will eventually fix.
2) ethdriver_seL4Ethdriver_0.c is generated from the CAmkES template for the
seL4DTBHardware connector. The template is located in
camkes/templates/seL4DTBHardware-to.template.c in the CAmkES folder which will
either be in projects/camkes-tool or tools/camkes from the root of the manifest
directory, depending on which manifest you initialised your project from.
Sincerely,
Damon
________________________________
From: KAP Benjamin <[email protected]>
Sent: Wednesday, 19 June 2019 11:34 AM
To: Lee, Damon (Data61, Kensington NSW); [email protected]
Subject: AW: Beaglebone Black: failed to find device frame
Hello
Thank you for the answer. I simply adjusted the values in
kernel/tools/dts/am335x.dts for now and kept the seL4DTBHardware connection.
I have more questions:
1) There are 2 implementations of low_level_init
- projects/global-components/components/PicoServer/src/eth_interface.c
- projects/util_libs/libethdrivers/src/plat/am335x/beaglebone.c
What decides which one to invoke? or is the in beaglebone.c not necessary
at all?
2) How is projects/camkes/picoserver/ethdriver_seL4Ethdriver_0.c generated?
I am debugging my current implementation which gets stuck before
ethriver_mac().
Sincerely,
Benjamin
________________________________
Von: Lee, Damon (Data61, Kensington NSW) [[email protected]]
Gesendet: Dienstag, 18. Juni 2019 03:36
An: KAP Benjamin; [email protected]
Betreff: Re: Beaglebone Black: failed to find device frame
Hi,
The problem is that there isn't any untyped memory available to make a 4K page
at address 0x4a101200 (if you notice carefully, this address isn't page
aligned).
The seL4DTBHardware connector doesn't support the AM335x board as the format of
the interrupt fields in the DTS doesn't follow that of the ARM GIC.
The page alignment problem is also a problem that I didn't encounter when
developing the seL4DTBHardware connector, so thanks for the alert.
So to resolve your problem you will have to use the seL4HardwareMMIO connector
and ask it to make a 4K mapping at 0x4a100000 and 0x4a101000.
You will also need to use the seL4HardwareInterrupt connector to generate the
interrupts.
Sincerely,
Damon
________________________________
From: Devel <[email protected]> on behalf of KAP Benjamin
<[email protected]>
Sent: Tuesday, 18 June 2019 4:10 AM
To: [email protected]
Subject: [seL4] Beaglebone Black: failed to find device frame
Hello
I am trying to add am335x support to the pico TCP/IP stack and currently
working on the following file:
projects/global-components/components/Ethdriver/include/plat/am335x/plat/eth_devices.h.
Current contents of this file (I am creating it step by step, thus it might be
incomplete):
#pragma once
#define HARDWARE_ETHERNET_COMPONENT
#define HARDWARE_ETHERNET_INTERFACES
\
consumes Dummy EthDriver;
\
emits Dummy dummy_source;
#define HARDWARE_ETHERNET_COMPOSITION
\
connection seL4DTBHardware ethernet_conn(from dummy_source, to EthDriver);
#define HARDWARE_ETHERNET_CONFIG
\
EthDriver.dtb = dtb({ "path" : "/ocp/ethernet@4a100000" });
\
EthDriver.generate_interrupts = 1;
I test the implementation by using the picoserver CAmkES application. However,
on boot I receive the following error:
ELF-loader started on CPU: ARM Ltd. Cortex-A8 r3p2
paddr=[82000000..8262e037]
No DTB found!
Looking for DTB in CPIO archive...
Found dtb at 820c1b84
Loaded dtb from 820c1b84
paddr=[80034000..8003cfff]
ELF-loading image 'kernel'
paddr=[80000000..80033fff]
vaddr=[f0000000..f0033fff]
virt_entry=f0000000
ELF-loading image 'capdl-loader'
paddr=[8003d000..8059afff]
vaddr=[10000..56dfff]
virt_entry=1e4dc
ELF loader relocated, continuing boot...
Enabling MMU and paging
Jumping to kernel-image entry point...
Bootstrapping kernel
Booting all finished, dropped to user space
[email protected]:726 device frame/untyped, paddr = 0x48040000, size = 12
bits
[email protected]:726 device frame/untyped, paddr = 0x48042000, size = 12
bits
[email protected]:726 device frame/untyped, paddr = 0x4a100000, size = 12
bits
[email protected]:726 device frame/untyped, paddr = 0x4a101200, size = 12
bits
[email protected]:730 [Cond failed: err != seL4_NoError]
Failed to find device frame/untyped at paddr = 0x4a101200
seL4 root server abort()ed
Debug halt syscall from user thread 0xffefd600 "rootserver"
halting...
Kernel entry via Unknown syscall, word: 65
The am335x.dtb contains the following line in ethernet@4a100000:
reg = <0x4a100000 0x00000800 0x4a101200 0x00000100>;
I did find related posts
(http://sel4.systems/pipermail/devel/2016-June/000850.html,
http://sel4.systems/pipermail/devel/2018-July/002031.html and
http://sel4.systems/pipermail/devel/2015-October/000530.html) but didn't help
me that much.<http://sel4.systems/pipermail/devel/2018-July/002031.html).>
If I am correct the hardware block isn't enabled but I don't know exactly how
to do this.
Could anyone help me out here or give me some hints?
Best Regards,
Kap Benjamin
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