Hi Taeung!

I think your goal is to make SD controller work on L4Linux right ? If my guess is right then I could share my experience since I did something similar.

First you need to create the 'devs' file and 'vbus' file with the hardware resource information( IO address and IRQ number). These could be found on the reference manual of you board. This step assure L4Linux's accessibility of related hardware resource.

Then you need to find out which SD controller driver is the one that your board is using. This could be done by looking into the defconfig of your board.

Since L4Linux is different from ARM Linux, there should be lots of configs unavailable when you select ARCH=l4, including those related to devices and drivers, because of the dependency check of Linux build system. You have to manually modify them one by one to pass the dependency check. This step is very complicated.

Here's an example: https://github.com/Ksys-labs/L4Reap This project has made some devices work on L4Linux. Maybe you can learn how they did from it.

On Mon, Apr 21, 2014 at 9:19 PM, Taeung treeze.taeung@gmail.com wrote:

Hello, Matthias :-)

Would you mind I ask you a question ?

I did not understood your answer, because I was uncertain it. But, now I'm catching on. I'm analyzing 'L4 Re' document.

I've modified 'l4lx-vbus.io' and 'arm-rv-eb-mc.devs' file as follows..

*vi 'l4lx-vbus.io http://l4lx-vbus.io**'*

# vim:set ft=ioconfig: # configuration file for io

l4linux => new System_bus() { NIC => wrap(hw-root.NIC); FLASHMEMORY => wrap(hw-root.FLASHMEMORY); } ============

*vi 'arm-rv-eb-mc.devs'*

local Hw = Io.Hw local Res = Io.Res

Io.hw_add_devices {

FLASHMEMORY = Hw.Device { hid = "flashmemory"; Res.mmio(0x02198000 , 0x0219BFFF);

},

NIC = Hw.Device { hid = "smsc911x"; Res.mmio(0x02188000, 0x0218BFFF); Res.irq(41); }, } ============

But I've failed booting with kernel commandline '....root=/dev/mtdblock0p1...' to set RootFilesystem as SD card(/dev/mtdblock0p1).

The log is ...

...(*omitted*)

Added static device '(noname)' with 0 resources.

Added static device 'NIC' with 2 resources.

Added static device 'FLASHMEMORY' with 1 resources.

...(*omitted*)

L4 serial driver

ttyLv0 at MMIO 0x1 (irq = 211, base_baud = 230400) is a L4

l4ser_shm: L4 shared mem serial driver

l4cdds: No name given, not starting.

brd: module loaded

l4bdds: No name given, not starting.

mousedev: PS/2 mouse device common for all mice

TCP: cubic registered

NET: Registered protocol family 17

Waiting for root device /dev/mtdblock0p1...

============

The log message has been stopped at 'Waiting for root device /dev/mtdblock0p1... '

I guess kernel command line is wrong. Is my guess right ?

Or is '.io' , '.devs' file wrong ?

If anyone give me small hints , I would appreciate.

• Taeung -

On 04/01/2014 09:23 PM, Matthias Lange wrote:

Hi,

On Tue, Apr 01, 2014 at 07:07:44PM +0900, Taeung wrote:

Hello, L4 hackers :-)

I want to change *root device* on L4 Linux instead of ramdisk. Root device I want is like '*/dev/mtdblock0*' or '/dev/mmcblk1p1' instead of 'rom/ramdisk-arm.rd'.

So, I've configured somethings in 'L4 Linux menuconfig', additionally. Somethings are as follows .. ============================== <*> MMC/SD/SDIO card support --->

<*> The Extended 4 (ext4) filesystem [*] Ext4 POSIX Access Control Lists [*] Ext4 Security Labels ============================== kernel command line : "rom/vmlinuz.arm console=ttyLv0 root=/dev/mtdblock0 rootwait rw " ============================== But it is hangs at '*Waiting for root device /dev/mtdblock0...*'.

I've heard that the solution of this is to pass-through the physical MMC device to L4Linux. Please, tell me it's concrete ways or hints about what I must study for solving this. I can't even guess what the solution mean.. please.

First you need to identify the native Linux driver for the SD controller. Then you need to identify all the resources (IO memory, GPIO pins, IRQs, clocks, ...) the driver requires. Then you need to make those resources available to L4Linux. Most likely you have to define a custom L4Linux ARM platform and create a platform file which defines all devices for it. Then the first step is to get the SD driver successfully pass the probe function.

Matthias.

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