python3-dtc: add SRCPV and fix missing symbol

We need some of the latest dtc functionality for lopper, but that
puts us out of sync with the main dtc recipe in oe-core master.

To show that we are running ahead, bumping the PV to include SRCPV.

To fix the following missing symbol:

| ImportError: qemuarm64-poky-linux/xen-image-minimal/1.0-r0/recipe-sysroot-native/usr/lib/python3.10/site-packages/_libfdt.cpython-310-x86_64-linux-gnu.so: undefined symbol: fdt_overlay_target_offset

We revert the commit that introduces it (since we don't need that
functionality), and will drop our revert when oe-core updates to
a similar version.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

2 files changed, 131 insertions, 0 deletions

diff --git a/recipes-kernel/dtc/python3-dtc/0001-Revert-libfdt-overlay-make-overlay_get_target-public.patch b/recipes-kernel/dtc/python3-dtc/0001-Revert-libfdt-overlay-make-overlay_get_target-public.patch
new file mode 100644
index 00000000..cf4739eb
--- /dev/null
+++ b/recipes-kernel/dtc/python3-dtc/0001-Revert-libfdt-overlay-make-overlay_get_target-public.patch
@@ -0,0 +1,129 @@
+From 4d4703e0199fb3556c37694e4d951785abca22fd Mon Sep 17 00:00:00 2001
+From: Bruce Ashfield <bruce.ashfield@gmail.com>
+Date: Wed, 19 Jan 2022 12:46:42 -0500
+Subject: [PATCH] Revert "libfdt: overlay: make overlay_get_target() public"
+
+This reverts commit 45f3d1a095dd3440578d5c6313eba555a791f3fb.
+---
+ libfdt/fdt_overlay.c | 29 ++++++++++++++++++++++-------
+ libfdt/libfdt.h      | 18 ------------------
+ libfdt/version.lds   |  1 -
+ 3 files changed, 22 insertions(+), 26 deletions(-)
+
+diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
+index 5c0c398..d217e79 100644
+--- a/libfdt/fdt_overlay.c
++++ b/libfdt/fdt_overlay.c
+@@ -40,22 +40,37 @@ static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
+        return fdt32_to_cpu(*val);
+ }
+ 
+-int fdt_overlay_target_offset(const void *fdt, const void *fdto,
+-                             int fragment_offset, char const **pathp)
++/**
++ * overlay_get_target - retrieves the offset of a fragment's target
++ * @fdt: Base device tree blob
++ * @fdto: Device tree overlay blob
++ * @fragment: node offset of the fragment in the overlay
++ * @pathp: pointer which receives the path of the target (or NULL)
++ *
++ * overlay_get_target() retrieves the target offset in the base
++ * device tree of a fragment, no matter how the actual targeting is
++ * done (through a phandle or a path)
++ *
++ * returns:
++ *      the targeted 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, char const **pathp)
+ {
+        uint32_t phandle;
+        const char *path = NULL;
+        int path_len = 0, ret;
+ 
+        /* Try first to do a phandle based lookup */
+-       phandle = overlay_get_target_phandle(fdto, fragment_offset);
++       phandle = overlay_get_target_phandle(fdto, fragment);
+        if (phandle == (uint32_t)-1)
+                return -FDT_ERR_BADPHANDLE;
+ 
+        /* no phandle, try path */
+        if (!phandle) {
+                /* And then a path based lookup */
+-               path = fdt_getprop(fdto, fragment_offset, "target-path", &path_len);
++               path = fdt_getprop(fdto, fragment, "target-path", &path_len);
+                if (path)
+                        ret = fdt_path_offset(fdt, path);
+                else
+@@ -621,7 +636,7 @@ static int overlay_merge(void *fdt, void *fdto)
+                if (overlay < 0)
+                        return overlay;
+ 
+-               target = fdt_overlay_target_offset(fdt, fdto, fragment, NULL);
++               target = overlay_get_target(fdt, fdto, fragment, NULL);
+                if (target < 0)
+                        return target;
+ 
+@@ -764,7 +779,7 @@ static int overlay_symbol_update(void *fdt, void *fdto)
+                        return -FDT_ERR_BADOVERLAY;
+ 
+                /* get the target of the fragment */
+-               ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
++               ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+                if (ret < 0)
+                        return ret;
+                target = ret;
+@@ -786,7 +801,7 @@ static int overlay_symbol_update(void *fdt, void *fdto)
+ 
+                if (!target_path) {
+                        /* again in case setprop_placeholder changed it */
+-                       ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
++                       ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+                        if (ret < 0)
+                                return ret;
+                        target = ret;
+diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
+index a7f432c..7f117e8 100644
+--- a/libfdt/libfdt.h
++++ b/libfdt/libfdt.h
+@@ -2116,24 +2116,6 @@ int fdt_del_node(void *fdt, int nodeoffset);
+  */
+ int fdt_overlay_apply(void *fdt, void *fdto);
+ 
+-/**
+- * fdt_overlay_target_offset - retrieves the offset of a fragment's target
+- * @fdt: Base device tree blob
+- * @fdto: Device tree overlay blob
+- * @fragment_offset: node offset of the fragment in the overlay
+- * @pathp: pointer which receives the path of the target (or NULL)
+- *
+- * fdt_overlay_target_offset() retrieves the target offset in the base
+- * device tree of a fragment, no matter how the actual targeting is
+- * done (through a phandle or a path)
+- *
+- * returns:
+- *      the targeted node offset in the base device tree
+- *      Negative error code on error
+- */
+-int fdt_overlay_target_offset(const void *fdt, const void *fdto,
+-                             int fragment_offset, char const **pathp);
+-
+ /**********************************************************************/
+ /* Debugging / informational functions                                */
+ /**********************************************************************/
+diff --git a/libfdt/version.lds b/libfdt/version.lds
+index cbce5d4..7ab85f1 100644
+--- a/libfdt/version.lds
++++ b/libfdt/version.lds
+@@ -77,7 +77,6 @@ LIBFDT_1.2 {
+                fdt_appendprop_addrrange;
+                fdt_setprop_inplace_namelen_partial;
+                fdt_create_with_flags;
+-               fdt_overlay_target_offset;
+        local:
+                *;
+ };
+-- 
+2.19.1
+
diff --git a/recipes-kernel/dtc/python3-dtc_1.6.1.bb b/recipes-kernel/dtc/python3-dtc_1.6.1.bb
index dd2c6e6e..a82e6d05 100644
--- a/recipes-kernel/dtc/python3-dtc_1.6.1.bb
+++ b/recipes-kernel/dtc/python3-dtc_1.6.1.bb
@@ -7,6 +7,7 @@ LICENSE = "GPLv2 | BSD-2-Clause"
 DEPENDS = "flex-native bison-native swig-native python3-setuptools-scm-native libyaml dtc"
 
 SRC_URI = "git://git.kernel.org/pub/scm/utils/dtc/dtc.git;branch=master \
+           file://0001-Revert-libfdt-overlay-make-overlay_get_target-public.patch \
           "
 
 UPSTREAM_CHECK_GITTAGREGEX = "v(?P<pver>\d+(\.\d+)+)"
@@ -15,6 +16,7 @@ LIC_FILES_CHKSUM = "file://pylibfdt/libfdt.i;beginline=1;endline=6;md5=afda088c9
 
 SRCREV = "4048aed12b81c5a0154b9af438edc99ec7d2b6a1"
 
+PV = "1.6.1+git${SRCPV}"
 S = "${WORKDIR}/git"
 
 inherit setuptools3 pkgconfig