tests: Introduce DT overlay tests
This adds a bunch of unit tests for the "fdt apply" command.
They've all been run successfully in the sandbox. However, as you still
require an out-of-tree dtc with overlay support, this is disabled by
default.
Acked-by: Simon Glass <sjg@chromium.org>
Acked-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c
index 1dac8fd..40b6d27 100644
--- a/lib/libfdt/fdt_overlay.c
+++ b/lib/libfdt/fdt_overlay.c
@@ -5,6 +5,20 @@
#include "libfdt_internal.h"
+/**
+ * overlay_get_target_phandle - retrieves the target phandle of a fragment
+ * @fdto: pointer to the device tree overlay blob
+ * @fragment: node offset of the fragment in the overlay
+ *
+ * overlay_get_target_phandle() retrieves the target phandle of an
+ * overlay fragment when that fragment uses a phandle (target
+ * property) instead of a path (target-path property).
+ *
+ * returns:
+ * the phandle pointed by the target property
+ * 0, if the phandle was not found
+ * -1, if the phandle was malformed
+ */
static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
{
const uint32_t *val;
@@ -14,12 +28,26 @@
if (!val)
return 0;
- if ((*val == 0xffffffff) || (len != sizeof(*val)))
- return 0xffffffff;
+ if ((*val == (uint32_t)-1) || (len != sizeof(*val)))
+ return (uint32_t)-1;
return fdt32_to_cpu(*val);
}
+/**
+ * overlay_get_target - retrieves the target phandle of a fragment
+ * @fdt: Base device tree blob
+ * @fdto: Device tree overlay blob
+ * @fragment: node offset of the fragment in the overlay
+ *
+ * overlay_get_target() retrieves the target phandle in the base
+ * device tree of a fragment, no matter how the actual targetting is
+ * done (through a phandle or a path)
+ *
+ * returns:
+ * the targetted node offset in the base device tree
+ * Negative error code on error
+ */
static int overlay_get_target(const void *fdt, const void *fdto,
int fragment)
{
@@ -28,7 +56,7 @@
/* Try first to do a phandle based lookup */
phandle = overlay_get_target_phandle(fdto, fragment);
- if (phandle == -1)
+ if (phandle == (uint32_t)-1)
return -FDT_ERR_BADPHANDLE;
if (phandle)
@@ -42,6 +70,20 @@
return fdt_path_offset(fdt, path);
}
+/**
+ * overlay_phandle_add_offset - Increases a phandle by an offset
+ * @fdt: Base device tree blob
+ * @node: Device tree overlay blob
+ * @name: Name of the property to modify (phandle or linux,phandle)
+ * @delta: offset to apply
+ *
+ * overlay_phandle_add_offset() increments a node phandle by a given
+ * offset.
+ *
+ * returns:
+ * 0 on success.
+ * Negative error code on error
+ */
static int overlay_phandle_add_offset(void *fdt, int node,
const char *name, uint32_t delta)
{
@@ -64,6 +106,21 @@
return fdt_setprop_inplace_u32(fdt, node, name, adj_val);
}
+/**
+ * overlay_adjust_node_phandles - Offsets the phandles of a node
+ * @fdto: Device tree overlay blob
+ * @node: Offset of the node we want to adjust
+ * @delta: Offset to shift the phandles of
+ *
+ * overlay_adjust_node_phandles() adds a constant to all the phandles
+ * of a given node. This is mainly use as part of the overlay
+ * application process, when we want to update all the overlay
+ * phandles to not conflict with the overlays of the base device tree.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_adjust_node_phandles(void *fdto, int node,
uint32_t delta)
{
@@ -95,6 +152,20 @@
return 0;
}
+/**
+ * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
+ * @fdto: Device tree overlay blob
+ * @delta: Offset to shift the phandles of
+ *
+ * overlay_adjust_local_phandles() adds a constant to all the
+ * phandles of an overlay. This is mainly use as part of the overlay
+ * application process, when we want to update all the overlay
+ * phandles to not conflict with the overlays of the base device tree.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_adjust_local_phandles(void *fdto, uint32_t delta)
{
/*
@@ -103,6 +174,25 @@
return overlay_adjust_node_phandles(fdto, 0, delta);
}
+/**
+ * overlay_update_local_node_references - Adjust the overlay references
+ * @fdto: Device tree overlay blob
+ * @tree_node: Node offset of the node to operate on
+ * @fixup_node: Node offset of the matching local fixups node
+ * @delta: Offset to shift the phandles of
+ *
+ * overlay_update_local_nodes_references() update the phandles
+ * pointing to a node within the device tree overlay by adding a
+ * constant delta.
+ *
+ * This is mainly used as part of a device tree application process,
+ * where you want the device tree overlays phandles to not conflict
+ * with the ones from the base device tree before merging them.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_update_local_node_references(void *fdto,
int tree_node,
int fixup_node,
@@ -113,41 +203,49 @@
int ret;
fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) {
- const uint32_t *val = NULL;
- uint32_t adj_val, index;
+ const unsigned char *fixup_val, *tree_val;
const char *name;
int fixup_len;
int tree_len;
+ int i;
- val = fdt_getprop_by_offset(fdto, fixup_prop,
- &name, &fixup_len);
- if (!val)
+ fixup_val = fdt_getprop_by_offset(fdto, fixup_prop,
+ &name, &fixup_len);
+ if (!fixup_val)
return fixup_len;
- index = fdt32_to_cpu(*val);
- val = fdt_getprop(fdto, tree_node, name, &tree_len);
- if (!val)
+ tree_val = fdt_getprop(fdto, tree_node, name, &tree_len);
+ if (!tree_val)
return tree_len;
- /*
- * The index can be unaligned.
- *
- * Use a memcpy for the architectures that do not
- * support unaligned accesses.
- */
- memcpy(&adj_val, (unsigned char *)val + index,
- sizeof(uint32_t));
+ for (i = 0; i < fixup_len; i += sizeof(uint32_t)) {
+ uint32_t adj_val, index;
- adj_val = fdt32_to_cpu(adj_val);
- adj_val += delta;
- adj_val = cpu_to_fdt32(adj_val);
+ index = *(uint32_t *)(fixup_val + i);
+ index = fdt32_to_cpu(index);
- ret = fdt_setprop_inplace_namelen_partial(fdto, tree_node,
- name, strlen(name),
- index, &adj_val,
- sizeof(adj_val));
- if (ret)
- return ret;
+ /*
+ * phandles to fixup can be unaligned.
+ *
+ * Use a memcpy for the architectures that do
+ * not support unaligned accesses.
+ */
+ memcpy(&adj_val, tree_val + index, sizeof(uint32_t));
+
+ adj_val = fdt32_to_cpu(adj_val);
+ adj_val += delta;
+ adj_val = cpu_to_fdt32(adj_val);
+
+ ret = fdt_setprop_inplace_namelen_partial(fdto,
+ tree_node,
+ name,
+ strlen(name),
+ index,
+ &adj_val,
+ sizeof(adj_val));
+ if (ret)
+ return ret;
+ }
}
fdt_for_each_subnode(fdto, fixup_child, fixup_node) {
@@ -171,11 +269,28 @@
return 0;
}
-static int overlay_update_local_references(void *dto, uint32_t delta)
+/**
+ * overlay_update_local_references - Adjust the overlay references
+ * @fdto: Device tree overlay blob
+ * @delta: Offset to shift the phandles of
+ *
+ * overlay_update_local_references() update all the phandles pointing
+ * to a node within the device tree overlay by adding a constant
+ * delta to not conflict with the base overlay.
+ *
+ * This is mainly used as part of a device tree application process,
+ * where you want the device tree overlays phandles to not conflict
+ * with the ones from the base device tree before merging them.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
+static int overlay_update_local_references(void *fdto, uint32_t delta)
{
int fixups;
- fixups = fdt_path_offset(dto, "/__local_fixups__");
+ fixups = fdt_path_offset(fdto, "/__local_fixups__");
if (fixups < 0) {
/* There's no local phandles to adjust, bail out */
if (fixups == -FDT_ERR_NOTFOUND)
@@ -187,10 +302,33 @@
/*
* Update our local references from the root of the tree
*/
- return overlay_update_local_node_references(dto, 0, fixups,
+ return overlay_update_local_node_references(fdto, 0, fixups,
delta);
}
+/**
+ * overlay_fixup_one_phandle - Set an overlay phandle to the base one
+ * @fdt: Base Device Tree blob
+ * @fdto: Device tree overlay blob
+ * @symbols_off: Node offset of the symbols node in the base device tree
+ * @path: Path to a node holding a phandle in the overlay
+ * @path_len: number of path characters to consider
+ * @name: Name of the property holding the phandle reference in the overlay
+ * @name_len: number of name characters to consider
+ * @index: Index in the overlay property where the phandle is stored
+ * @label: Label of the node referenced by the phandle
+ *
+ * overlay_fixup_one_phandle() resolves an overlay phandle pointing to
+ * a node in the base device tree.
+ *
+ * This is part of the device tree overlay application process, when
+ * you want all the phandles in the overlay to point to the actual
+ * base dt nodes.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_fixup_one_phandle(void *fdt, void *fdto,
int symbols_off,
const char *path, uint32_t path_len,
@@ -225,6 +363,25 @@
&phandle, sizeof(phandle));
};
+/**
+ * overlay_fixup_phandle - Set an overlay phandle to the base one
+ * @fdt: Base Device Tree blob
+ * @fdto: Device tree overlay blob
+ * @symbols_off: Node offset of the symbols node in the base device tree
+ * @property: Property offset in the overlay holding the list of fixups
+ *
+ * overlay_fixup_phandle() resolves all the overlay phandles pointed
+ * to in a __local_fixup__ property, and updates them to match the
+ * phandles in use in the base device tree.
+ *
+ * This is part of the device tree overlay application process, when
+ * you want all the phandles in the overlay to point to the actual
+ * base dt nodes.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off,
int property)
{
@@ -275,57 +432,98 @@
return 0;
}
-static int overlay_fixup_phandles(void *dt, void *dto)
+/**
+ * overlay_fixup_phandles - Resolve the overlay phandles to the base
+ * device tree
+ * @fdt: Base Device Tree blob
+ * @fdto: Device tree overlay blob
+ *
+ * overlay_fixup_phandles() resolves all the overlay phandles pointing
+ * to nodes in the base device tree.
+ *
+ * This is one of the steps of the device tree overlay application
+ * process, when you want all the phandles in the overlay to point to
+ * the actual base dt nodes.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
+static int overlay_fixup_phandles(void *fdt, void *fdto)
{
int fixups_off, symbols_off;
int property;
- symbols_off = fdt_path_offset(dt, "/__symbols__");
- fixups_off = fdt_path_offset(dto, "/__fixups__");
+ symbols_off = fdt_path_offset(fdt, "/__symbols__");
+ fixups_off = fdt_path_offset(fdto, "/__fixups__");
- fdt_for_each_property_offset(property, dto, fixups_off)
- overlay_fixup_phandle(dt, dto, symbols_off, property);
+ fdt_for_each_property_offset(property, fdto, fixups_off) {
+ int ret;
+
+ ret = overlay_fixup_phandle(fdt, fdto, symbols_off, property);
+ if (ret)
+ return ret;
+ }
return 0;
}
-static int apply_overlay_node(void *dt, int target,
- void *dto, int fragment)
+/**
+ * overlay_apply_node - Merge an overlay fragment into the base device tree
+ * @fdt: Base Device Tree blob
+ * @target: Node offset in the base device tree to apply the fragment to
+ * @fdto: Device tree overlay blob
+ * @fragment: Node offset in the overlay holding the changes to merge
+ *
+ * overlay_apply_node() merges an overlay fragment into a target base
+ * device tree node pointed.
+ *
+ * This is part of the final step in the device tree overlay
+ * application process, when all the phandles have been adjusted and
+ * resolved and you just have to merge overlay into the base device
+ * tree.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
+static int overlay_apply_node(void *fdt, int target,
+ void *fdto, int fragment)
{
int property;
int node;
- fdt_for_each_property_offset(property, dto, fragment) {
+ fdt_for_each_property_offset(property, fdto, fragment) {
const char *name;
const void *prop;
int prop_len;
int ret;
- prop = fdt_getprop_by_offset(dto, property, &name,
+ prop = fdt_getprop_by_offset(fdto, property, &name,
&prop_len);
if (prop_len == -FDT_ERR_NOTFOUND)
return -FDT_ERR_INTERNAL;
if (prop_len < 0)
return prop_len;
- ret = fdt_setprop(dt, target, name, prop, prop_len);
+ ret = fdt_setprop(fdt, target, name, prop, prop_len);
if (ret)
return ret;
}
- fdt_for_each_subnode(dto, node, fragment) {
- const char *name = fdt_get_name(dto, node, NULL);
+ fdt_for_each_subnode(fdto, node, fragment) {
+ const char *name = fdt_get_name(fdto, node, NULL);
int nnode;
int ret;
- nnode = fdt_add_subnode(dt, target, name);
+ nnode = fdt_add_subnode(fdt, target, name);
if (nnode == -FDT_ERR_EXISTS)
- nnode = fdt_subnode_offset(dt, target, name);
+ nnode = fdt_subnode_offset(fdt, target, name);
if (nnode < 0)
return nnode;
- ret = apply_overlay_node(dt, nnode, dto, node);
+ ret = overlay_apply_node(fdt, nnode, fdto, node);
if (ret)
return ret;
}
@@ -333,6 +531,21 @@
return 0;
}
+/**
+ * overlay_merge - Merge an overlay into its base device tree
+ * @fdt: Base Device Tree blob
+ * @fdto: Device tree overlay blob
+ *
+ * overlay_merge() merges an overlay into its base device tree.
+ *
+ * This is the final step in the device tree overlay application
+ * process, when all the phandles have been adjusted and resolved and
+ * you just have to merge overlay into the base device tree.
+ *
+ * returns:
+ * 0 on success
+ * Negative error code on failure
+ */
static int overlay_merge(void *dt, void *dto)
{
int fragment;
@@ -350,7 +563,7 @@
if (overlay < 0)
return overlay;
- ret = apply_overlay_node(dt, target, dto, overlay);
+ ret = overlay_apply_node(dt, target, dto, overlay);
if (ret)
return ret;
}