a question about falcon mode

Alex G. mr.nuke.me at gmail.com
Thu Nov 25 15:57:07 CET 2021

On 11/25/21 1:07 AM, Chan Kim wrote:
> Hello all,
> I'm trying to implement falcon mode for our board. Then should I first
> implement the normal mode(spl + proper)?
> It looks like so while I'm reading doc/README.falcon. (It says, after
> loading kernel, DT etc. I should give 'spl export' command).

Falcon mode is a bit board dependent.  There are a couple of ways you 
could go about this.

The first is to have an "fdtargs" partition. This is where "spl export" 
comes in. Once you run "spl export", it will give a modified dtb at 
"$fdtargsaddr". It's that DTB that you need to write to your ftdargs 
partition. For example:

     > spl export fdt $loadaddr - $fdt_addr_r
     > mmc write $fdtargsaddr 0x9800 0x8000

In this example the ftdargs partition starts at sector 0x9800, and is 
0x800 sectors long.

The second option is to forget about "spl export" and "fdtargs", and 
package your kernel, devicetree, and overlays in a FIT container. You'd 
make sure to enable SPL_LOAD_FIT_APPLY_OVERLAY. There isn't much more to 
this other than the usual gotcha's with FIT and overlays.


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