From bcdd02328e65130915965fdc378c89bb8e2c08bc Mon Sep 17 00:00:00 2001
From: Greg Malysa <greg.malysa@timesys.com>
Date: Tue, 19 Mar 2024 22:16:07 -0400
Subject: [PATCH] build: Revive and update LDR format support

LDR format files are used primarily by Analog Devices processors but may
be of interest to other vendors. Previously support existed for this
format as part of the U-Boot build, but it has been unmaintained and
unused for a long time. In preparation for adding support for modern ADI
processors that use LDR, modernize the LDR support:

- Introduce CONFIG_LDR_CPU as the CPU string recognized by the LDR tool
  may not be the same as CONFIG_CPU
- Add an SPL target that repackages u-boot-spl inside an LDR file

An almost identical target for packaging u-boot into an LDR file already
exists and did not need to be created.

Co-developed-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
Signed-off-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Greg Malysa <greg.malysa@timesys.com>
---
 Kconfig              | 14 ++++++++++++++
 Makefile             |  2 +-
 scripts/Makefile.spl |  5 +++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/Kconfig b/Kconfig
index 75f9563ce6..82df59f176 100644
--- a/Kconfig
+++ b/Kconfig
@@ -715,6 +715,20 @@ config SYS_CLK_FREQ
 	  A static value for the CPU frequency.  Note that if not required
 	  for a given SoC, this can be left at 0.
 
+config HAS_LDR
+	bool
+	help
+	  Enables building .ldr targets for U-Boot and SPL. This does not
+	  automatically build any additional targets with make or buildman.
+
+config LDR_CPU
+	string "CPU name to be passed to LDR utility."
+	depends on HAS_LDR
+	help
+	  Set the CPU name for the -T parameter in the LDR utility.  This is
+	  generally used on processors from Analog Devices, but may be also
+	  be useful for other vendors.
+
 source "api/Kconfig"
 
 endmenu		# General setup
diff --git a/Makefile b/Makefile
index 1069adca91..7321fe1499 100644
--- a/Makefile
+++ b/Makefile
@@ -1360,7 +1360,7 @@ u-boot-nodtb.bin: u-boot FORCE
 
 u-boot.ldr:	u-boot
 		$(CREATE_LDR_ENV)
-		$(LDR) -T $(CONFIG_CPU) -c $@ $< $(LDR_FLAGS)
+		$(LDR) -T $(CONFIG_LDR_CPU) -c $@ $< $(LDR_FLAGS)
 		$(BOARD_SIZE_CHECK)
 
 # binman
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index 60db38d5bd..1868f1beef 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -381,6 +381,11 @@ $(obj)/$(BOARD)-spl.bin: $(obj)/u-boot-spl.bin
 	$(objtree)/tools/mkexynosspl) $(VAR_SIZE_PARAM) $< $@
 endif
 
+$(obj)/u-boot-spl.ldr: $(obj)/u-boot-spl
+	$(CREATE_LDR_ENV)
+	$(LDR) -T $(CONFIG_LDR_CPU) -c $@ $< $(LDR_FLAGS)
+	$(BOARD_SIZE_CHECK)
+
 quiet_cmd_objcopy = OBJCOPY $@
 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
 
-- 
2.39.5