[PATCH v8 30/32] fdt: Makefile: Ensure that OF_BOARD is used when needed

[Simon Glass]

Boards which define OF_HAS_PRIOR_STAGE must define OF_BOARD at present,
since a custom function is the only way to obtain the devicetree at
runtime.

Add a build error when this requirement is not met, to avoid accepting
any patches which break this requirement.

Add a whitelist for boards which use it, currently none. This whitelist
can be updated for local development, if needed.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v8:
- Add new patch to ensure that OF_BOARD is used when needed

 Makefile                 |  7 +++++++
 scripts/check-of.sh      | 42 ++++++++++++++++++++++++++++++++++++++++
 scripts/of_whitelist.txt |  1 +
 3 files changed, 50 insertions(+)
 create mode 100755 scripts/check-of.sh
 create mode 100644 scripts/of_whitelist.txt

diff --git a/Makefile b/Makefile
index 6671c5d9e2f..98ef2642f68 100644
--- a/Makefile
+++ b/Makefile
@@ -1061,6 +1061,10 @@ quiet_cmd_cfgcheck = CFGCHK  $2
 cmd_cfgcheck = $(srctree)/scripts/check-config.sh $2 \
 		$(srctree)/scripts/config_whitelist.txt $(srctree)
 
+quiet_cmd_ofcheck = OFCHK   $2
+cmd_ofcheck = $(srctree)/scripts/check-of.sh $2 \
+		$(srctree)/scripts/of_whitelist.txt
+
 # Concat the value of all the CONFIGs (result is 'y' or 'yy', etc. )
 got = $(foreach cfg,$(1),$($(cfg)))
 
@@ -1139,6 +1143,9 @@ endif
 	@# know about unless they are in Kconfig. All the existing CONFIG
 	@# options are whitelisted, so new ones should not be added.
 	$(call cmd,cfgcheck,u-boot.cfg)
+	@# Check that this build does not override OF_HAS_PRIOR_STAGE by
+	@# disabling OF_BOARD.
+	$(call cmd,ofcheck,$(KCONFIG_CONFIG))
 
 PHONY += dtbs
 dtbs: dts/dt.dtb
diff --git a/scripts/check-of.sh b/scripts/check-of.sh
new file mode 100755
index 00000000000..3ce7105cad4
--- /dev/null
+++ b/scripts/check-of.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+# Copyright 2021 Google LLC
+# Written by Simon Glass <sjg at chromium.org>
+#
+# Check that the .config file provided does not try to disable OF_BOARD for
+# boards that use CONFIG_OF_HAS_PRIOR_STAGE
+#
+# Usage
+#    check-of.sh <path to .config> <path to whitelist file>
+#
+# For example:
+#   scripts/check-of.sh b/chromebook_link/u-boot.cfg kconfig_whitelist.txt
+#
+# Exit code is 0 if OK, 3 if the .config is wrong, as above
+
+set -e
+set -u
+
+PROG_NAME="${0##*/}"
+
+usage() {
+	echo "$PROG_NAME <path to .config> <path to whitelist file>"
+	exit 1
+}
+
+[ $# -ge 2 ] || usage
+
+path="$1"
+whitelist="$2"
+
+sys_config="$(sed -n 's/CONFIG_SYS_CONFIG_NAME="\(.*\)"$/\1/p' "${path}")"
+
+if grep -q OF_HAS_PRIOR_STAGE=y "${path}"; then
+	if ! grep -lq CONFIG_OF_BOARD=y "${path}"; then
+		echo >&2 "This board uses a prior stage to provide the device tree."
+		echo >&2 "Please enable CONFIG_OF_BOARD to ensure that it works correctly."
+		if grep -q "${sys_config}" "${whitelist}"; then
+			exit 0
+		fi
+		exit 3
+	fi
+fi
diff --git a/scripts/of_whitelist.txt b/scripts/of_whitelist.txt
new file mode 100644
index 00000000000..e82cf557bb2
--- /dev/null
+++ b/scripts/of_whitelist.txt
@@ -0,0 +1 @@
+# List of boards which are permitted to use OF_HAS_PRIOR_STAGE without OF_BOARD
-- 
2.34.1.173.g76aa8bc2d0-goog