[PATCH] Introduce fdt_setprop_placeholder() method
From: Pantelis Antoniou <hidden>
Date: 2017-07-27 16:33:11
Subsystem:
the rest · Maintainer:
Linus Torvalds
In some cases you need to add a property but the contents of it are not known at creation time, merely the extend of it. This method allows you to create a property of a given size which will be set to zero while a pointer to the property data will be provided. Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org> --- libfdt/fdt_rw.c | 20 +++++++++++++++++--- libfdt/libfdt.h | 31 +++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+), 3 deletions(-)
diff --git a/libfdt/fdt_rw.c b/libfdt/fdt_rw.c
index 8b487f6..5c3a2bb 100644
--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c@@ -269,8 +269,8 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name) return 0; } -int fdt_setprop(void *fdt, int nodeoffset, const char *name, - const void *val, int len) +int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name, + int len, void **prop_data) { struct fdt_property *prop; int err;
@@ -283,8 +283,22 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name, if (err) return err; + *prop_data = prop->data; + return 0; +} + +int fdt_setprop(void *fdt, int nodeoffset, const char *name, + const void *val, int len) +{ + void *prop_data; + int err; + + err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data); + if (err) + return err; + if (len) - memcpy(prop->data, val, len); + memcpy(prop_data, val, len); return 0; }
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index a248b1b..313c72a 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h@@ -1449,6 +1449,37 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name, const void *val, int len); /** + * fdt_setprop _placeholder - allocate space for a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @len: length of the property value + * @prop_data: return pointer to property data + * + * fdt_setprop_placeholer() allocates the named property in the given node. + * If the property exists it is resized. In either case a pointer to the + * property data is returned. + * + * This function may insert or delete data from the blob, and will + * therefore change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to + * contain the new property value + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ +int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name, + int len, void **prop_data); + +/** * fdt_setprop_u32 - set a property to a 32-bit integer * @fdt: pointer to the device tree blob * @nodeoffset: offset of the node whose property to change
--
2.1.4
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