Le Tue, 3 May 2022 08:45:11 -0500, Rob Herring <robh@xxxxxxxxxx> a écrit : > On Wed, Apr 27, 2022 at 11:45:00AM +0200, Clément Léger wrote: > > When enabling CONFIG_OF on a platform where of_root is not populated by > > firmware, we end up without a root node. In order to apply overlays and > > create subnodes of the root node, we need one. This commit creates an > > empty root node if not present. > > The existing unittest essentially does the same thing for running the > tests on non-DT systems. It should be modified to use this support > instead. Maybe that's just removing the unittest code that set of_root. Acked, I'll try the unit test on my system. > > I expect Frank will have some comments. > > > Co-developed-by: Rob Herring <robh@xxxxxxxxxx> > > Signed-off-by: Rob Herring <robh@xxxxxxxxxx> > > Signed-off-by: Clément Léger <clement.leger@xxxxxxxxxxx> > > --- > > drivers/of/base.c | 16 ++++++++++++++-- > > 1 file changed, 14 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index e7d92b67cb8a..6b8584c39f73 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -177,6 +177,19 @@ void __init of_core_init(void) > > pr_err("failed to register existing nodes\n"); > > return; > > } > > + > > + if (!of_root) { > > + of_root = kzalloc(sizeof(*of_root), GFP_KERNEL); > > + if (!of_root) { > > + mutex_unlock(&of_mutex); > > + pr_err("failed to create root node\n"); > > + return; > > + } > > + > > + of_root->full_name = "/"; > > + of_node_init(of_root); > > + } > > + > > for_each_of_allnodes(np) { > > __of_attach_node_sysfs(np); > > if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)]) > > @@ -185,8 +198,7 @@ void __init of_core_init(void) > > mutex_unlock(&of_mutex); > > > > /* Symlink in /proc as required by userspace ABI */ > > - if (of_root) > > - proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); > > + proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); > > } > > > > static struct property *__of_find_property(const struct device_node *np, > > -- > > 2.34.1 > > > > -- Clément Léger, Embedded Linux and Kernel engineer at Bootlin https://bootlin.com