From: Maxime Ripard <maxime.rip...@free-electrons.com> The device tree overlays are a good way to deal with user-modifyable boards or boards with some kind of an expansion mechanism where we can easily plug new board in (like the BBB, the Raspberry Pi or the CHIP).
Add a new function to merge overlays with a base device tree. Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- cpukit/include/libfdt.h | 31 +++++++++++++++++++++++++++++++ cpukit/include/libfdt_env.h | 1 + 2 files changed, 32 insertions(+) diff --git a/cpukit/include/libfdt.h b/cpukit/include/libfdt.h index d2e5e031fb..c69e918899 100644 --- a/cpukit/include/libfdt.h +++ b/cpukit/include/libfdt.h @@ -1763,6 +1763,37 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name); */ int fdt_del_node(void *fdt, int nodeoffset); +/** + * fdt_overlay_apply - Applies a DT overlay on a base DT + * @fdt: pointer to the base device tree blob + * @fdto: pointer to the device tree overlay blob + * + * fdt_overlay_apply() will apply the given device tree overlay on the + * given base device tree. + * + * Expect the base device tree to be modified, even if the function + * returns an error. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there's not enough space in the base device tree + * -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or + * properties in the base DT + * -FDT_ERR_BADPHANDLE, + * -FDT_ERR_BADOVERLAY, + * -FDT_ERR_NOPHANDLES, + * -FDT_ERR_INTERNAL, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADOFFSET, + * -FDT_ERR_BADPATH, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_TRUNCATED, standard meanings + */ +int fdt_overlay_apply(void *fdt, void *fdto); + /**********************************************************************/ /* Debugging / informational functions */ /**********************************************************************/ diff --git a/cpukit/include/libfdt_env.h b/cpukit/include/libfdt_env.h index 9dea97dfff..99f936dacc 100644 --- a/cpukit/include/libfdt_env.h +++ b/cpukit/include/libfdt_env.h @@ -54,6 +54,7 @@ #include <stddef.h> #include <stdint.h> +#include <stdlib.h> #include <string.h> #ifdef __CHECKER__ -- 2.13.7 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
