bsp: rkbin: ddr: allow to customize DDR bin blob

Rockchip provides a tool to customize the DDR bin blob which can prove
to be extremely useful, for example if your HW doesn't follow the HW
reference design and uses a different UART controller or UART mux for
the serial console, or use a different baudrate.

If RKBIN_DDR_RECONFIGURE is set to 1 for a machine, a ddrbin_params.txt
needs to be provided for said machine and ddrbin_tool.py will be run
against it to generate a new custom binary with the desired config.

Note that future implementations may allow to provide configuration
through a different mechanism than a simple and difficult to
maintain/modify file. E.g. this doesn't really work well when one wants
to have this in sync with SERIAL_CONSOLES for example. But that may be
much harder to support as the serial controller index in
SERIAL_CONSOLES does not necessarily match the hardware index expected
by ddrbin_params.txt. It also doesn't provide the UART mux.

In any case, I believe this is a decent start at allowing customization
of the DDR bin blob without having to provide a blob directly in-tree.

Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>

README

@@ -55,7 +55,7 @@ Status of supported boards:
 
 Notes:
 -----
-  Custom DDR rkbin version:
+  Customize DDR rkbin:
 	If you wish to use a different version of DDR binary provided by
 	rockchip-rkbin-ddr recipe than the one in this layer, you can create a
 	.bbappend in your own layer, and accordingly set SRCREV (possibly
@@ -70,6 +70,24 @@ Notes:
 		DDRBIN_VERS:my-machine = "v2.07"
 		DDRBIN_FILE:my-machine = "rk3308_ddr_451MHz_uart4_m0_${DDRBIN_VERS}.bin"
 
+	If you wish to use a configuration for the DDR binary blob provided in
+	rockchip-rkbin-ddr recipe that differs from the default, you can set the
+	RKBIN_DDR_RECONFIGURE variable to 1 for your machine, e.g.:
+
+		RKBIN_DDR_RECONFIGURE:my-machine = "1"
+
+	You will need to provide your custom ddrbin_param.txt via your bbappend, e.g.
+	your ddrbin_param in
+	meta-my-layer/recipes-bsp/rkbin/rockchip-rkbin-ddr/my-machine/ddrbin_param.txt
+	and a bbappend, e.g. in meta-my-layer/recipes-bsp/rkbin/rockchip-rkbin-ddr_git.bbappend,
+	which contains:
+
+		FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
+
+	As for the content of ddrbin_param.txt,
+	https://github.com/rockchip-linux/rkbin/blob/master/tools/ddrbin_tool_user_guide.txt
+	may help.
+
   rk3308 rkbin:
 	The latest ddr initializer for the rk3308 platform does not output
 	diagnostic messages to uart0. This causes a bunch of gibberish to

recipes-bsp/rkbin/rockchip-rkbin-ddr_git.bb

@@ -6,6 +6,7 @@ DDRBIN_DIR:rk3308 ?= "bin/rk33/"
 DDRBIN_VERS:rk3308 ?= "v2.10"
 DDRBIN_FILE:rk3308 ?= "rk3308_ddr_589MHz_uart4_m0_${DDRBIN_VERS}.bin"
 DDRBIN_DEPLOY_FILENAME:rk3308 ?= "ddr-rk3308.bin"
+DDRBIN_TOOL_SOC:rk3308 ?= "rk3308"
 
 do_deploy:rk3308() {
 	# Prebuilt U-Boot TPL (DDR init)
@@ -16,6 +17,7 @@ DDRBIN_DIR:rk3566 ?= "bin/rk35/"
 DDRBIN_VERS:rk3566 ?= "v1.23"
 DDRBIN_FILE:rk3566 ?= "rk3566_ddr_1056MHz_${DDRBIN_VERS}.bin"
 DDRBIN_DEPLOY_FILENAME:rk3566 ?= "ddr-rk3566.bin"
+DDRBIN_TOOL_SOC:rk3566 ?= "rk356x"
 
 do_deploy:rk3566() {
 	# Prebuilt U-Boot TPL (DDR init)
@@ -26,6 +28,7 @@ DDRBIN_DIR:rk3568 ?= "bin/rk35/"
 DDRBIN_VERS:rk3568 ?= "v1.23"
 DDRBIN_FILE:rk3568 ?= "rk3568_ddr_1560MHz_${DDRBIN_VERS}.bin"
 DDRBIN_DEPLOY_FILENAME:rk3568 ?= "ddr-rk3568.bin"
+DDRBIN_TOOL_SOC:rk3568 ?= "rk356x"
 
 do_deploy:rk3568() {
 	# Prebuilt U-Boot TPL (DDR init)
@@ -36,8 +39,49 @@ DDRBIN_DIR:rk3588s ?= "bin/rk35/"
 DDRBIN_VERS:rk3588s ?= "v1.18"
 DDRBIN_FILE:rk3588s ?= "rk3588_ddr_lp4_2112MHz_lp5_2400MHz_${DDRBIN_VERS}.bin"
 DDRBIN_DEPLOY_FILENAME:rk3588s ?= "ddr-rk3588.bin"
+DDRBIN_TOOL_SOC:rk3588s ?= "rk3588"
 
 do_deploy:rk3588s() {
 	# Prebuilt U-Boot TPL (DDR init)
 	install -m 644 ${S}/${DDRBIN_DIR}${DDRBIN_FILE} ${DEPLOYDIR}/${DDRBIN_DEPLOY_FILENAME}
 }
+
+# The following is only required if DDR bin blob needs to be modified
+# (e.g. different UART controller, UART mux, or baudrate)
+# RKBIN_DDR_RECONFIGURE = "1" if it needs to be modified, all below logic needs to
+# depend on that value be 1, and not run if 0.
+RKBIN_DDR_RECONFIGURE ?= "0"
+
+# The tool (ddrbin_tool.py) for modifying the DDR bin is from rockchip-rkbin-native...
+DEPENDS += "${@'rockchip-rkbin-native' if d.getVar('RKBIN_DDR_RECONFIGURE') == '1' else ''}"
+
+# ... and it expects a file as input, which is named ddrbin_param.txt in the tree.
+SRC_URI += "${@'file://ddrbin_param.txt' if d.getVar('RKBIN_DDR_RECONFIGURE') == '1' else ''}"
+
+python __anonymous() {
+    # Because rockchip-rkbin.inc inherits bin_package and we need to run some step before
+    # the install task re-enable do_configure task.
+    # We could use
+    #  do_configure[noexec] = "${@'0' if d.getVar('RKBIN_DDR_RECONFIGURE') == '1' else '1'}"
+    # but this spams the console with deprecation warnings, see
+    # https://bugzilla.yoctoproject.org/show_bug.cgi?id=13808
+    if d.getVar('RKBIN_DDR_RECONFIGURE') == '1':
+        d.delVarFlag("do_configure", "noexec")
+}
+
+do_configure() {
+	if [ "${RKBIN_DDR_RECONFIGURE}" = "1" ]; then
+		# ddrbin_tool.py always modifies a date in the DDR blob, based on current time.
+		# This is bad for reproducibility and hashequiv usage, so use the commit author
+		# date of the last change made to the DDR bin.
+		# DATE must be max 17-character long!
+		RKBIN_DDR_DATE=$(git log --pretty=format:"%ad" --date=format:"%Y%m%d-%H:%M:%S" -1 -- ${S}/${DDRBIN_DIR}${DDRBIN_FILE})
+		# DDRBIN_TOOL_SOC is mostly useless except for rk3528 for now. It needs to match one string in the global
+		# chip_list array in ddrbin_tool.py.
+		if [ -z "${DDRBIN_TOOL_SOC}" ]; then
+			bbfatal "Non-empty DDRBIN_TOOL_SOC:<MACHINE> required!"
+		fi
+		# Modify blob with appropriate settings stored in ddrbin_params.txt
+		ddrbin_tool.py ${DDRBIN_TOOL_SOC} ${UNPACKDIR}/ddrbin_param.txt ${S}/${DDRBIN_DIR}${DDRBIN_FILE} --verinfo_editable "${RKBIN_DDR_DATE}"
+	fi
+}