Hi Fiona, I'll review and test this the coming week and provide feedback.
On Tue, 11 Feb 2025 at 13:58, Fiona Klute <fiona.kl...@gmx.de> wrote: > Both the Raspberry Pi downstream kernel [1] and some userspace tools > [2] use the revision property to identify the board, and the latter > fails if it is absent. The firmware creates the /system node, so we > need to do the same. > > [1] > https://github.com/raspberrypi/linux/blob/0f292fbb6346b05766152902076895558ac23f9a/arch/arm/mach-bcm/board_bcm2835.c#L23-L33 > [2] > https://github.com/jgarff/rpi_ws281x/blob/7fc0bf8b31d715bbecf28e852ede5aaa388180da/rpihw.c#L579 > > Signed-off-by: Fiona Klute <fiona.kl...@gmx.de> > Cc: Matthias Brugger <mbrug...@suse.com> > Cc: Peter Robinson <pbrobin...@gmail.com> > Cc: Tom Rini <tr...@konsulko.com> > --- > I'm sending this as RFC because I'm not sure if creating a temporary > overlay is the best approach here, advice on a better way to create the > /system node if needed is very much welcome. I know I'll need to add > more error checks, I'll do that after I know I have the right approach. > > board/raspberrypi/rpi/rpi.c | 37 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 37 insertions(+) > > diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c > index aa39afa338a..647716127c7 100644 > --- a/board/raspberrypi/rpi/rpi.c > +++ b/board/raspberrypi/rpi/rpi.c > @@ -550,6 +550,41 @@ int copy_property(void *dst, void *src, char *path, > char *property) > return fdt_setprop(dst, dst_offset, property, prop, len); > } > > +int copy_system_node(void *fdt, void *fw_fdt) > +{ > + const fdt32_t *prop; > + char fdto[2048]; > + int src_offset; > + int len; > + > + src_offset = fdt_path_offset(fw_fdt, "/system"); > + if (src_offset < 0) > + return -1; > + > + fdt_create(fdto, sizeof(fdto)); > + fdt_finish_reservemap(fdto); > + fdt_begin_node(fdto, ""); > + fdt_begin_node(fdto, "fragment"); > + fdt_property_string(fdto, "target-path", "/"); > + fdt_begin_node(fdto, "__overlay__"); > + fdt_begin_node(fdto, "system"); > + > + prop = fdt_getprop(fw_fdt, src_offset, "linux,serial", &len); > + if (prop) > + fdt_property(fdto, "linux,serial", prop, len); > + prop = fdt_getprop(fw_fdt, src_offset, "linux,revision", &len); > + if (prop) > + fdt_property(fdto, "linux,revision", prop, len); > + > + fdt_end_node(fdto); > + fdt_end_node(fdto); > + fdt_end_node(fdto); > + fdt_end_node(fdto); > + fdt_finish(fdto); > + > + fdt_overlay_apply_verbose(fdt, fdto); > +} > + > /* Copy tweaks from the firmware dtb to the loaded dtb */ > void update_fdt_from_fw(void *fdt, void *fw_fdt) > { > @@ -560,6 +595,8 @@ void update_fdt_from_fw(void *fdt, void *fw_fdt) > /* The firmware provides a more precise model; so copy that */ > copy_property(fdt, fw_fdt, "/", "model"); > > + copy_system_node(fdt, fw_fdt); > + > /* memory reserve as suggested by the firmware */ > copy_property(fdt, fw_fdt, "/", "memreserve"); > > -- > 2.47.2 > >
