[PATCH 1/3] 8xx: Analogue & Micro Adder875 board support.
bodonoghue at codehermit.ie
Tue Jan 15 09:40:07 EST 2008
On Mon, 2008-01-14 at 09:28 -0600, Scott Wood wrote:
> On Sun, Jan 13, 2008 at 02:26:12PM +0000, Bryan O'Donoghue wrote:
> > I've applied your code against Linus' git v2.6.26-rc7 as at today.
> > I have to apply
> It should apply against paulus's tree.
> > make adder87x-uboot_defconfig
> > make uImage
> make zImage, not uImage.
> > cp arch/powerpc/boot/uImage /tftpboot - which is my tftpd root
> > directory.
> Use cuImage.8xx, not uImage.
> > In U-Boot then.
> > => tftpboot 0x400000 uImage
> > => bootm 0x400000
> 0x400000 is where u-boot is going to want to relocate the image to, so
> loading the uImage there may not work.
Hmm, some old code I did to make Linux boot from the former ppc stuff
works fine to the loading and booting @ 0x4000000 - this step is pretty
much fine, I think.
> Yes, a uImage target will be expecting to be handed a device tree. The
> cuImage target has a device tree embedded and accepts the old-style bd_t.
This explains eveything then.. there _is_ a magic image and I haven't
been booting it !
I'll give the 8xx-centric ucImage a go.
> > /* pass open firmware flat tree */
> > #define CONFIG_OF_LIBFDT 1
> > #undef CONFIG_OF_FLAT_TREE
> > #define CONFIG_OF_BOARD_SETUP 1
> > #define CONFIG_OF_HAS_BD_T 1
> > #define CONFIG_OF_HAS_UBOOT_ENV 1
> > #define OF_CPU "PowerPC,875 at 0"
> > #define OF_SOC "soc875 at ff000000"
> > #define OF_TBCLK (bd->bi_busfreq / 4)
> You'll probably need some 8xx-specific code if you want to go this route.
> You'd also need to change the bootm command line to the three-argument
> version, with the third argument being the address of the device tree
> blob (the second argument can be - if there's no initrd).
Ah OK, I see so the procedure would be to dtc a dts representing the
Download both this and a uImage ... and then as you say pass the address
of the blob to Linux via U-Boot.
It occurs to me that this type of procedure should really be added to
There's no mention of it in the Linux documentation, nor in the u-boot
documentation and uncle Google was not informative for the types of
searches I was doing....
Somebody - possibly even me, since I'm mentioning it - should write a
copule of paragraphs on booting a ucImage with a of-blob and add it to
both U-Boot and Linux..
> If you're not comfortable with the device tree stuff, I recommend just
> using cuImage for now.
Thanks for the response Scott. I'll try out the ucImage and all going
well with that will try the three parameter Linux + blob based on
the .dts, hopefully over the next three or four days....
If I'm unlucky I might bug you again... and if I have more luck, I'll do
a follow up on the list.
Happy Monday !
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