-----Original Message----- From: Jerry Van Baren [mailto:gerald.vanbaren@ge.com] Sent: den 13 december 2007 20:00 To: Kumar Gala Cc: joakim.tjernlund@transmode.se; U-BOOT Subject: Re: [U-Boot-Users] libfdt problem when loading device tree
Kumar Gala wrote:
On Dec 13, 2007, at 10:24 AM, Joakim Tjernlund wrote:
I get this when I try to boot my board: ## Booting image at 00200000 ... Image Name: oskernel02a:p1a:99 Created: 2007-12-13 9:59:43 UTC Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 1238992 Bytes = 1.2 MB Load Address: 00000000 Entry Point: 00000000 Verifying Checksum ... OK Uncompressing Kernel Image ... OK Loading Device Tree to 007fe000, end 007ff6f9 ... OK WARNING: could not create /bd_t FDT_ERR_NOSPACE. fdt_bd_t: FDT_ERR_NOSPACE ERROR: /bd_t node create failed - must RESET the board to recover. Resetting the board.
I have tried different combinations of -S and -R options to dtc, but nothing helps: dtc -S 2000 -R 2000 -f of-tmcu.dts -O asm > of-tmcu.S
If I remove the chosen node from my dts file, I get the error when libfdt tries to create a chosen node.
I am using dtc 1.0.0 and u-boot 1.3.1
How big is the .dtb if you don't specify -S? The -R should
only be
something like 8.
- k
More trivia for Jocke:
Thanks for telling me this
Note that there now also is a "-s nnnn" option (IIRC and if you have the latest dtc) which *adds* nnnn bytes to the blob rather than making the blob a fixed size nnnn (IIRC, Kumar created it). Depending on your circumstances and preferences, this could be a better choice than -S.
I was about to suggest this after my mishap but got distracted. It is a useful option and I will probably use it in the future. Perhaps you should error out if the space is too small when using -S? That would have saved me some time.
Having the /chosen node already in the blob has severe limitations. Improving that is in my "todo" list: "...a suggestion by Scott Wood to make the /chosen handling finer grained: if the /chosen node exists, currently u-boot-fdt bails out. A better methodology is to not overwrite pre-existing properties on a per-property basis, so if /chosen exists but a necessary /chosen/property doesn't, it gets created."
IOW, if you create a blob with /chosen, you must have *everything* necessary in it because it won't be fixed up at runtime.
I don't need a chosen node in my dts, I just added it to get futher. Maybe others do.
Tip: if you do "fdt chosen" and then "fdt print /chosen", it will tell you exactly what your board fixup code put in the /chosen node.
Will have a look tmw, still very behind on device tree stuff.
FWIIW, I created a patch to implement Scott's suggestion, but it needs to be resurrected, rebased, and tested.
Good luck and thanks again.
Jocke