Add a function to modify inplace a property starting from a given index.
This is especially useful when the property is an array of values, and you want to update one of them without changing the DT size.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- include/libfdt.h | 34 +++++++++++++++++++++++++++++++--- lib/libfdt/fdt_wip.c | 13 ++++++++----- 2 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/include/libfdt.h b/include/libfdt.h index 4643be5adf39..2c8a42bcb667 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -1032,6 +1032,27 @@ int fdt_size_cells(const void *fdt, int nodeoffset); /* Write-in-place functions */ /**********************************************************************/
+/** + * fdt_setprop_inplace_namelen_by_index - change a property's value, + * but not its size + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @namelen: number of characters of name to consider + * @index: index of the property to change in the array + * @val: pointer to data to replace the property value with + * @len: length of the property value + * + * Identical to fdt_setprop_inplace(), but modifies the given property + * starting from the given index, and using only the first characters + * of the name. It is useful when you want to manipulate only one value of + * an array and you have a string that doesn't end with \0. + */ +int fdt_setprop_inplace_namelen_by_index(void *fdt, int nodeoffset, + const char *name, int namelen, + uint32_t index, const void *val, + int len); + /** * fdt_setprop_inplace - change a property's value, but not its size * @fdt: pointer to the device tree blob @@ -1060,8 +1081,13 @@ int fdt_size_cells(const void *fdt, int nodeoffset); * -FDT_ERR_BADSTRUCTURE, * -FDT_ERR_TRUNCATED, standard meanings */ -int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, - const void *val, int len); +static inline int fdt_setprop_inplace(void *fdt, int nodeoffset, + const char *name, const void *val, + int len) +{ + return fdt_setprop_inplace_namelen_by_index(fdt, nodeoffset, name, + strlen(name), 0, val, len); +}
/** * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property @@ -1095,7 +1121,9 @@ static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset, const char *name, uint32_t val) { fdt32_t tmp = cpu_to_fdt32(val); - return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp)); + return fdt_setprop_inplace_namelen_by_index(fdt, nodeoffset, + name, strlen(name), + 0, &tmp, sizeof(tmp)); }
/** diff --git a/lib/libfdt/fdt_wip.c b/lib/libfdt/fdt_wip.c index 9fe988655fe3..737769fa59e2 100644 --- a/lib/libfdt/fdt_wip.c +++ b/lib/libfdt/fdt_wip.c @@ -14,20 +14,23 @@
#include "libfdt_internal.h"
-int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, - const void *val, int len) +int fdt_setprop_inplace_namelen_by_index(void *fdt, int nodeoffset, + const char *name, int namelen, + uint32_t index, const void *val, + int len) { void *propval; int proplen;
- propval = fdt_getprop_w(fdt, nodeoffset, name, &proplen); + propval = fdt_getprop_namelen_w(fdt, nodeoffset, name, namelen, + &proplen); if (!propval) return proplen;
- if (proplen != len) + if (proplen < (len + index)) return -FDT_ERR_NOSPACE;
- memcpy(propval, val, len); + memcpy(propval + index, val, len); return 0; }