Re: Emdebian sprint / runtime device fingerprinting in bootloader
On 02/23/2011 10:28 AM, Somebody in the thread at some point said:
Any scripting config left from kernel package install could be
batched and deferred until first boot where it runs natively.
Hmm this is a bit too far-looking for me
I mention it because kernel post-install scriptlets was flagged as a
reason for needing a native environment for kernel install action in
linaro-media-create; by reserving those post-install actions to run at
the first boot that'd no longer be a problem.
If that was fixed then it'd be possible to have, eg, a single Omap4
kernel package and a single Omap4 bootloader package that worked on
all supported Omap4 boards and so on.
So John Rigby had proposed a similar approach, but Steve Sakoman had
suggested that it's really hard to identify the board you're running on
safely. And you need the information of the exact board relatively
early because you need to setup DDR, access the MMC and serial console
1) You only need to identify between boards of the same arch.
2) If the boards are so similar they can't be told apart, then from the
bootloader's perspective of just needing to init a minimum of assets to
"load and boot" Linux, then typically there will zero differences and we
don't actually care, or one difference that matters, the particular
SDRAM chips being used.
3) Things than can contribute to fingerprinting include JEDEC IDs in
NAND and NOR, SPI or I2C id codes and version, detection of default pin
state for pins wired differently.
Maybe Steve Sakoman can suggest some example boards that will be
difficult to tell apart at runtime, but it matters?