scripts: gen-dtb-s: reference OF IMD entries automatically

We currently require IMD_OF_USED to get the DT compatible into the
barebox image data meta section. As the PBL is already referencing the
DT to pass it along to barebox proper, let's add a reference from the DT
to the image data section to make IMD_OF_USED unnecessary.

--
v1 -> v2:
  - use dword, to fix build for 64-bit (Sascha)
  - place IMD reference before STRUCT_ALIGNMENT

Suggested-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20230404101706.2237453-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 39 insertions, 0 deletions

diff --git a/include/asm-generic/pointer.h b/include/asm-generic/pointer.h
new file mode 100644
index 0000000000..8b9600b029
--- /dev/null
+++ b/include/asm-generic/pointer.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_GENERIC_PTR_H___
+#define __ASM_GENERIC_PTR_H___
+
+#if __SIZEOF_POINTER__ == 8
+#ifdef __ASSEMBLY__
+#define ASM_PTR		.quad
+#define ASM_SZPTR	8
+#define ASM_LGPTR	3
+#else
+#define ASM_PTR		".quad"
+#define ASM_SZPTR	"8"
+#define ASM_LGPTR	"3"
+#endif
+#elif __SIZEOF_POINTER__ == 4
+#ifdef __ASSEMBLY__
+#define ASM_PTR		.word
+#define ASM_SZPTR	4
+#define ASM_LGPTR	2
+#else
+#define ASM_PTR		".word"
+#define ASM_SZPTR	"4"
+#define ASM_LGPTR	"2"
+#endif
+#else
+#error "Unexpected __SIZEOF_POINTER__"
+#endif
+
+#endif /* __ASM_GENERIC_PTR_H___ */
diff --git a/scripts/gen-dtb-s b/scripts/gen-dtb-s
index c5c46a4d86..f6fa152593 100755
--- a/scripts/gen-dtb-s
+++ b/scripts/gen-dtb-s
@@ -5,6 +5,7 @@ dtb=$2
 imd=$3
 
 echo "#include <asm/barebox.lds.h>"
+echo "#include <asm-generic/pointer.h>"
 
 le32() {
 	printf ".byte 0x%02x, 0x%02x, 0x%02x, 0x%02x\n" \
@@ -49,6 +50,10 @@ echo "__dtb_${name}_start:"
 echo ".incbin \"$dtb\""
 echo "__dtb_${name}_end:"
 echo ".global __dtb_${name}_end"
+if [ "$imd" = "y" ]; then
+	echo ".balign ASM_SZPTR"
+	echo "ASM_PTR __barebox_imd_OF_${name}"
+fi
 echo ".balign STRUCT_ALIGNMENT"
 
 compressed=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" $dtb.z)
@@ -65,5 +70,9 @@ printf ".int 0x%08x\n"  $uncompressed
 echo ".incbin \"$dtb.z\""
 echo "__dtb_z_${name}_end:"
 echo ".global __dtb_z_${name}_end"
+if [ "$imd" = "y" ]; then
+	echo ".balign ASM_SZPTR"
+	echo "ASM_PTR __barebox_imd_OF_${name}"
+fi
 echo ".balign STRUCT_ALIGNMENT"
 echo "#endif"