On Fri, Dec 29, 2017 at 10:12:04AM -0800, Nathan Whitehorn wrote:
> Has anyone had a chance to look at this? We need it, or something like it,
> to support some older firmwares with the FreeBSD kernel and I would like to
> make sure that our copy of libfdt does not diverge from upstream.
Sorry, I've been busy and haven't had a chance to look at it. I
haven't forgotten..
>
> Thanks,
> Nathan
>
> On 12/07/17 22:31, Nathan Whitehorn wrote:
> > This can be useful in particular in the kernel when booting on systems
> > with FDT-emitting firmware that is out of date. Releases of kexec-tools
> > on ppc64 prior to the end of 2014 are notable examples of such.
> >
> > Signed-off-by: Nathan Whitehorn <nwhitehorn@xxxxxxxxxxx>
> > ---
> > fdtget.c | 4 +--
> > libfdt/fdt.c | 8 ++++--
> > libfdt/fdt_ro.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
> > libfdt/libfdt.h | 5 +++-
> > 4 files changed, 79 insertions(+), 15 deletions(-)
> >
> > diff --git a/fdtget.c b/fdtget.c
> > index 6cc5242..34d8194 100644
> > --- a/fdtget.c
> > +++ b/fdtget.c
> > @@ -140,7 +140,6 @@ static int show_data(struct display_info *disp, const char *data, int len)
> > */
> > static int list_properties(const void *blob, int node)
> > {
> > - const struct fdt_property *data;
> > const char *name;
> > int prop;
> > @@ -149,8 +148,7 @@ static int list_properties(const void *blob, int node)
> > /* Stop silently when there are no more properties */
> > if (prop < 0)
> > return prop == -FDT_ERR_NOTFOUND ? 0 : prop;
> > - data = fdt_get_property_by_offset(blob, prop, NULL);
> > - name = fdt_string(blob, fdt32_to_cpu(data->nameoff));
> > + fdt_getprop_by_offset(blob, prop, &name, NULL);
> > if (name)
> > puts(name);
> > prop = fdt_next_property_offset(blob, prop);
> > diff --git a/libfdt/fdt.c b/libfdt/fdt.c
> > index fd13236..e783e6a 100644
> > --- a/libfdt/fdt.c
> > +++ b/libfdt/fdt.c
> > @@ -84,8 +84,9 @@ const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
> > return NULL;
> > if (fdt_version(fdt) >= 0x11)
> > - if (((offset + len) < offset)
> > - || ((offset + len) > fdt_size_dt_struct(fdt)))
> > + if (((offset + len) < offset) ||
> > + (fdt_version(fdt) >= 0x10 &&
> > + (offset + len) > fdt_size_dt_struct(fdt)))
> > return NULL;
> > return fdt_offset_ptr_(fdt, offset);
> > @@ -123,6 +124,9 @@ uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
> > /* skip-name offset, length and value */
> > offset += sizeof(struct fdt_property) - FDT_TAGSIZE
> > + fdt32_to_cpu(*lenp);
> > + if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) > 8 &&
> > + ((offset - fdt32_to_cpu(*lenp)) % 8) != 0)
> > + offset += 4;
> > break;
> > case FDT_END:
> > diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
> > index ce17814..025dd0f 100644
> > --- a/libfdt/fdt_ro.c
> > +++ b/libfdt/fdt_ro.c
> > @@ -233,16 +233,26 @@ int fdt_path_offset(const void *fdt, const char *path)
> > const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
> > {
> > const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
> > + const char *nameptr;
> > int err;
> > if (((err = fdt_check_header(fdt)) != 0)
> > || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
> > goto fail;
> > + nameptr = nh->name;
> > +
> > + if (fdt_version(fdt) < 0x10) {
> > + const char *leaf;
> > + leaf = strrchr(nameptr, '/');
> > + if (leaf != NULL)
> > + nameptr = leaf+1;
> > + }
> > +
> > if (len)
> > - *len = strlen(nh->name);
> > + *len = strlen(nameptr);
> > - return nh->name;
> > + return nameptr;
> > fail:
> > if (len)
> > @@ -268,9 +278,9 @@ int fdt_next_property_offset(const void *fdt, int offset)
> > return nextprop_(fdt, offset);
> > }
> > -const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
> > - int offset,
> > - int *lenp)
> > +static const struct fdt_property *_fdt_get_property_by_offset(const void *fdt,
> > + int offset,
> > + int *lenp)
> > {
> > int err;
> > const struct fdt_property *prop;
> > @@ -289,11 +299,35 @@ const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
> > return prop;
> > }
> > +const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
> > + int offset,
> > + int *lenp)
> > +{
> > + /* Prior to version 16, properties may need realignment
> > + * and this API does not work. fdt_getprop_*() will, however. */
> > +
> > + if (fdt_version(fdt) < 0x10) {
> > + if (lenp)
> > + *lenp = -FDT_ERR_BADVERSION;
> > + return NULL;
> > + }
> > +
> > + return _fdt_get_property_by_offset(fdt, offset, lenp);
> > +}
> > +
> > const struct fdt_property *fdt_get_property_namelen(const void *fdt,
> > int offset,
> > const char *name,
> > int namelen, int *lenp)
> > {
> > + /* Prior to version 16, properties may need realignment
> > + * and this API does not work. fdt_getprop_*() will, however. */
> > + if (fdt_version(fdt) < 0x10) {
> > + if (lenp)
> > + *lenp = -FDT_ERR_BADVERSION;
> > + return NULL;
> > + }
> > +
> > for (offset = fdt_first_property_offset(fdt, offset);
> > (offset >= 0);
> > (offset = fdt_next_property_offset(fdt, offset))) {
> > @@ -324,12 +358,33 @@ const struct fdt_property *fdt_get_property(const void *fdt,
> > const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
> > const char *name, int namelen, int *lenp)
> > {
> > - const struct fdt_property *prop;
> > + const struct fdt_property *prop = NULL;
> > + int offset = nodeoffset;
> > - prop = fdt_get_property_namelen(fdt, nodeoffset, name, namelen, lenp);
> > - if (!prop)
> > + for (offset = fdt_first_property_offset(fdt, offset);
> > + (offset >= 0);
> > + (offset = fdt_next_property_offset(fdt, offset))) {
> > + if (!(prop = _fdt_get_property_by_offset(fdt, offset, lenp))) {
> > + if (lenp)
> > + *lenp = -FDT_ERR_INTERNAL;
> > + return NULL;
> > + }
> > +
> > + if (fdt_string_eq_(fdt, fdt32_to_cpu(prop->nameoff),
> > + name, namelen))
> > + break;
> > + }
> > +
> > + if (lenp && offset < 0)
> > + *lenp = offset;
> > +
> > + if (!prop || offset < 0)
> > return NULL;
> > + /* Handle realignment */
> > + if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
> > + fdt32_to_cpu(prop->len) > 8)
> > + return prop->data + 4;
> > return prop->data;
> > }
> > @@ -338,11 +393,15 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset,
> > {
> > const struct fdt_property *prop;
> > - prop = fdt_get_property_by_offset(fdt, offset, lenp);
> > + prop = _fdt_get_property_by_offset(fdt, offset, lenp);
> > if (!prop)
> > return NULL;
> > if (namep)
> > *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
> > +
> > + if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
> > + fdt32_to_cpu(prop->len) > 8)
> > + return prop->data + 4;
> > return prop->data;
> > }
> > diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
> > index baa882c..7ac3e8a 100644
> > --- a/libfdt/libfdt.h
> > +++ b/libfdt/libfdt.h
> > @@ -54,7 +54,7 @@
> > #include <libfdt_env.h>
> > #include <fdt.h>
> > -#define FDT_FIRST_SUPPORTED_VERSION 0x10
> > +#define FDT_FIRST_SUPPORTED_VERSION 0x02
> > #define FDT_LAST_SUPPORTED_VERSION 0x11
> > /* Error codes: informative error codes */
> > @@ -526,6 +526,9 @@ int fdt_next_property_offset(const void *fdt, int offset);
> > * fdt_property structure within the device tree blob at the given
> > * offset. If lenp is non-NULL, the length of the property value is
> > * also returned, in the integer pointed to by lenp.
> > + *
> > + * Note that this code only works on device tree versions >= 16. fdt_getprop()
> > + * works on all versions.
> > *
> > * returns:
> > * pointer to the structure representing the property
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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