Wolfgang Grandegger wrote:
Hello,
it want to report on my experience with using FDT to configure U-Boot dynamically for a custom board based on the MPC823. The customer wanted _one_ U-Boot and Linux image for various variants of that board mainly to simplify software maintenance. The following devices required configuration via FDT blob:
[snip]
The central question is to what extend we want to use the FDT to configure U-Boot. I already regard the extensive use of the FDT in Linux 2.6 as kind of overkill.
Beauty is in the eye of the beholder. :-)
In the kernel's defense, they are working in a vastly more diverse (hardware-wise) environment than us embedded guys and many of their users (probably overwhelmingly most of their users by a simple head count) have no desire to configure and build a custom kernel for their hardware.
Personally, it has been a looong time since I built an x86 kernel for one of my workstations. Since my workstation hardware is probeable, I don't need to do it. The FDT brings that configuration to non-probeable hardware by having wizards (that's us, kindly deposit your money at the door ;-) generate the hardware description that the kernel can use to auto-configure itself.
I look at the FDT as a kernel "make menuconfig" done once by the wizards rather than having to repeat it every time you want to upgrade your kernel.
"The Navy is a master plan designed by geniuses for execution by idiots." - Wouk, Herman: The Caine Mutiny : a novel of World War II
s/Navy/FDT/
Please comment.
Thanks. Wolfgang.
Thanks for the update, Wolfgang, and I'm pleased that it went so well.
gvb