[U-Boot-Users] Open Firmware support questions

Jerry Van Baren
2006-10-09T13:36:27Z

Hi All,

I've been working with the u-boot OF support and have some questions,
but don't know who to ask.

It appears that Pantelis Antoniou submitted the original ft_build.[ch]
code <http://patchwork.ozlabs.org/linuxppc/patch?id=2238> but there is
no copyright or license information in the files. Are these files his
or did they come from somewhere else?

My current state of affairs (not quite ready for prime time) is in:
http://www.cideas.us/cgi-bin/gitweb.cgi?p=u-boot/u-boot-pq2fads.git;a=summary

Things I'm working on:
* Added a "of" command to dump the blob
* Works well enough but is not in its final form
* Required a change to vsprintf to parse a "ll" (long long) attribute
as well as the existing "q" attribute for 64 bit entries.
* Printing a 64 bit entry (example: interrupt "reg" value has two 32
bit entries) doesn't work properly. Example print:
interrupt-controller at f8200000 {
linux,phandle = <0xf8200000>;
#address-cells = <0x00000000>;
#interrupt-cells = <0x00000002>;
interrupt-controller;
reg = <0x00000000f8200004>;
built-in;
device_type = "pci-pic";
};
The reg value
<0x00000000f8200004>
should print
<0xf8200000f8200004>
or, better(?),
<0xf8200000 f8200004>
The "better" format listed above is how it appears in the *.dts
tree definition, but the ft_dump.c routine doesn't appear to do
that format. It sees the size value of 8 and prints it as a
single long long rather than two longs (should be just a
formatting issue, but currently the print is broken). Note that
the tree itself appears to be OK, looking at the ASM output file.

* Looking at improving(?) the build mechanism
* Use the "asm" output format rather than a binary dump and then
regeneration via xxd.
* My thought (unimplemented as of yet) is to append "_of" to the
configuration so "PQ2FADS-ZU_lowboot_config" would become
"PQ2FADS-ZU_lowboot_config_of" for the OF version. The
configuration mechanism would then add the definition
FTOBJS := pq2fads.o
to the "include/config.mk" file.
* Questions:
* Is the "_of" tag reasonable or is there a better way? I'm
assuming we don't want to force everybody with an ADS-type board
over to using OF.
* Where should we put the original *.dts files? I picked up the
original mpc8260ads.dts file from the kernel source, Vitaly
Bordug's repository:
linux-2.6-PQ/arch/powerpc/boot/dts/mpc8272ads.dts

I forgot what the agreement ended up being for ownership between
the kernel people and Wolfgang (if there was any agreement ;-).
gvb