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. 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