virtex uImage and serial ports

Wed Dec 31 08:18:33 EST 2008

Gidday John,

Thanks for the clue.  This works.  Now to get a proper 2.6 style (with udev, sysfs and all those new fangled things) root filesystem up and running.  It boots fine with my old 2.4 style buildroot/busybox filesystem.

Thanks again.

Joshua

On Tuesday, 30 December, 2008 14:23, "John Linn" <John.Linn at xilinx.com> said:

> It's been a while, but here's what I remember.
> 
> You have to have SERIAL_OF* turned on in the kernel configuration to get
> the code to work.
> 
> Then the device tree gets parsed by of_serial.c functions for the 16550
> uart.
> 
> -- John
> 
>> -----Original Message-----
>> From: Joshua Lamorie [mailto:jpl at xiphos.ca]
>> Sent: Tuesday, December 30, 2008 12:14 PM
>> To: John Linn
>> Cc: linuxppc-embedded at ozlabs.org
>> Subject: RE: virtex uImage and serial ports
>>
>> Gidday John,
>>
>> Thanks for the pointer.  I think I have already gone through every
> possible page on the wiki, without
>> finding my answer.  There are some great pointers however, such as
>> http://xilinx.wikidot.com/debugging-kernel-boot-problems.
>>
>> As far as I can tell, if I do 'make uImage', there is no code built
> into vmlinux that will parse the
>> device tree and set up the serial ports (at least as far as I can see
> with objdump -S).  When it
>> boots, there is no console output and __log_buf doesn't show any
> serial ports detected during the
>> initialization of the serial driver.
>>
>> Which leads to my question, how does the 8250 serial driver get the
> information about the attached
>> serial ports from the dtb?  Which part of the code parses the dtb,
> finds the "ns16550" and
>> updates/builds the platform_device information for the 8250 serial
> port driver?
>>
>> Joshua
>>
>> On Tuesday, 30 December, 2008 13:16, "John Linn"
> <John.Linn at xilinx.com> said:
>>
>> > Hi Joshua,
>> >
>> > Have you looked at our wiki site at http://xilinx.wikidot.com as we
>> > quite a bit of information there.
>> >
>> > The ML405 board is a V2Pro chip so it should be pretty close to what
> you
>> > want using the default kernel config for virtex4.
>> >
>> > I haven't tested the console at 115,200 as I use it at 9600.
> Shouldn't
>> > be a problem, but may not hurt to stay at 9600 to get it working.
>> >
>> > There are pages on the wiki about using u-boot with the kernel also
> as
>> > it sounds like that's what you're doing.
>> >
>> > Thanks,
>> > John
>> >
>> >
>> >> -----Original Message-----
>> >> From: linuxppc-embedded-bounces+john.linn=xilinx.com at ozlabs.org
>> > [mailto:linuxppc-embedded-
>> >> bounces+john.linn=xilinx.com at ozlabs.org] On Behalf Of Joshua
> Lamorie
>> >> Sent: Wednesday, December 24, 2008 3:48 PM
>> >> To: linuxppc-embedded at ozlabs.org
>> >> Subject: virtex uImage and serial ports
>> >>
>> >> Gidday there,
>> >>
>> >> I am trying to get 2.6.27(ish) running on my custom Virtex-II Pro
>> > platform (I call it Q5).  I already
>> >> have many years of running 2.4.26 and booting from u-boot.
>> >>
>> >> The problem is getting the console running.  I have a device tree
> blob
>> > built and loaded into memory,
>> >> and by peeking at __log_buf I can see that it is reading this okay
>> > (i.e. it is correctly finding my
>> >> interrupt controller).  However, by the time it goes to mount the
>> > ramdisk as root, it complains that
>> >> there is no console.
>> >>
>> >> I'm fairly certain /chosen has stdout pointing to the correct UART,
>> > and the console arguments are
>> >> ttyS0,115200.
>> >>
>> >> In looking through the code however, I cannot figure out how the
>> > uImage code actually initializes the
>> >> serial-ports for the XILINX_VIRTEX_GENERIC_BOARD.  As I understand
> it,
>> > the only place where
>> >> serial_console_init is called, is within platform_init, and this
> isn't
>> > called for uImage.
>> >>
>> >> So, three questions.
>> >>
>> >> 1) How is the serial driver supposed to know where the platforms
>> > serial ports are?
>> >>
>> >> 2) If I wanted to scrap u-boot and just copy kernel/ramdisk/dtb to
>> > memory, which kernel make target
>> >> should I use?  dtbImage, simpleImage?
>> >>
>> >> 3) What is the best, most modern image to build that should be used
> by
>> > u-boot?
>> >>
>> >> Thanks in advance
>> >>
>> >> Joshua
>> >>
>> >> p.s. I've been trying with kernel.org mainline, xilinx git and denx
>> > ELDK xenomai (2.6.24).  U-boot is
>> >> built from latest git source.  DTS file built from XPS 9.1i with
>> > latest service packs, and turned
>> >> into DTB with latest dtc source from git.
>> >>
>> >>
>> >> --
>> >> Xiphos Technologies
>> >> (514) 847-9474 x227
>> >> (514) 848-9644 fax
>> >>
>> >> www.xiphos.com
>> >> _______________________________________________
>> >> The information transmitted is intended only for the
>> >> person or entity to which it is addressed and may contain
>> >> confidential and/or privileged material.  If you have
>> >> received this in error, please contact the sender and delete
>> >> this communication and any copy immediately. Thank you.
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> Linuxppc-embedded mailing list
>> >> Linuxppc-embedded at ozlabs.org
>> >> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>> >
>> >
>> > This email and any attachments are intended for the sole use of the
> named
>> > recipient(s) and contain(s) confidential information that may be
> proprietary,
>> > privileged or copyrighted under applicable law. If you are not the
> intended
>> > recipient, do not read, copy, or forward this email message or any
> attachments.
>> > Delete this email message and any attachments immediately.
>> >
>> >
>> > _______________________________________________
>> > Linuxppc-embedded mailing list
>> > Linuxppc-embedded at ozlabs.org
>> > https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>> >
>>
>>
>> --
>> Xiphos Technologies
>> (514) 847-9474 x227
>> (514) 848-9644 fax
>>
>> www.xiphos.com
>> _______________________________________________
>> The information transmitted is intended only for the
>> person or entity to which it is addressed and may contain
>> confidential and/or privileged material.  If you have
>> received this in error, please contact the sender and delete
>> this communication and any copy immediately. Thank you.
>>
>>
>>
>>
> 
> 
> This email and any attachments are intended for the sole use of the named
> recipient(s) and contain(s) confidential information that may be proprietary,
> privileged or copyrighted under applicable law. If you are not the intended
> recipient, do not read, copy, or forward this email message or any attachments.
> Delete this email message and any attachments immediately.
> 
> 
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded at ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> 

-- 
Xiphos Technologies
(514) 847-9474 x227
(514) 848-9644 fax

www.xiphos.com
_______________________________________________
The information transmitted is intended only for the
person or entity to which it is addressed and may contain
confidential and/or privileged material.  If you have
received this in error, please contact the sender and delete
this communication and any copy immediately. Thank you.