Hi Quentin, On Mon, 4 May 2026 at 06:59, Quentin Schulz <[email protected]> wrote: > > Hi Simon, > > On 5/4/26 2:49 PM, Simon Glass wrote: > > Hi Quentin, > > > > On Mon, 27 Apr 2026 at 03:14, Quentin Schulz <[email protected]> > > wrote: > >> > >> Hi Simon, Marek, > >> > >> On 4/22/26 4:31 AM, Simon Glass wrote: > >>> When producing a DTB from fdtgrep, there is no way to reserve extra > >>> space so that more nodes/properties can be added at runtime without > >>> growing totalsize first. > >>> > >> > >> Ok but why is that an issue? What is the actual usecase? What I'm afraid > >> of is that you pad enough and you hit random bugs because you forget > >> that adding enough properties can now hit the size limit and you forgot > >> to add the logic to resize/grow the fdt when it's too small to fit new > >> properties. > > > > I'm going to leave this question to Marek :-) > > > >> > >>> Add a -B/--pad option that appends a caller-specified number of free > >>> bytes after the strings section and grows totalsize accordingly. The > >>> padding is applied after fdt_pack(), so it is not reclaimed when -r is > >>> used. > >>> > >>> Suggested-by: Marek Vasut <[email protected]> > >>> Signed-off-by: Simon Glass <[email protected]> > >>> --- > >>> > >>> tools/binman/btool/fdtgrep.py | 3 ++- > >>> tools/fdtgrep.c | 31 ++++++++++++++++++++++++++++++- > >>> 2 files changed, 32 insertions(+), 2 deletions(-) > >>> > >>> diff --git a/tools/binman/btool/fdtgrep.py b/tools/binman/btool/fdtgrep.py > >>> index 446b2f4144b..7b393241878 100644 > >>> --- a/tools/binman/btool/fdtgrep.py > >>> +++ b/tools/binman/btool/fdtgrep.py > >>> @@ -16,9 +16,10 @@ Output formats are: > >>> dtb - device tree blob (sets -Hmt automatically) > >>> bin - device tree fragment (may not be a valid .dtb) > >>> > >>> -Options: -[haAc:b:C:defg:G:HIlLmn:N:o:O:p:P:rRsStTvhV] > >>> +Options: -[haAB:c:b:C:defg:G:HIlLmn:N:o:O:p:P:rRsStTvhV] > >>> -a, --show-address Display address > >>> -A, --colour Show all nodes/tags, colour those > >>> that match > >>> + -B, --pad <arg> Append free space to the output > >>> FDT, for later growth > >>> -b, --include-node-with-prop <arg> Include contains containing > >>> property > >>> -c, --include-compat <arg> Compatible nodes to include in > >>> grep > >>> -C, --exclude-compat <arg> Compatible nodes to exclude in > >>> grep > >> > >> I'm tempted to remove this and just tell people to look at the > >> documentation in tools/fdtgrep.c. Especially since we don't actually > >> allow the user to pass any of those parameters themselves via the > >> bintool, so it isn't actually useful. > > > > I would like fdtgrep to give useful help, though. It is a tool which > > can stand alone. > > > > Yes, but this here is docstring for the fdtgrep *Bintool* module which > actually doesn't support most of the arguments specified here. So I > would say it's more confusing to have it there than not have anything. > For sure we want to keep documentation of fdtgrep, the tool as in > tools/fdtgrep.c, complete and up-to-date!
Ah yes, I just generated it directly from fdtgrep. So perhaps we should have no argument docs here and just mention what the bintool actually supports / uses? Regards, Simon
