ARM: renesas: Add support for the r7s72100 Genmai board

Add r7s72100 Genmai board support. Serial console, NOR Flash and
Ethernet are known to work however on-board SDRAM is not yet enabled.

Signed-off-by: Magnus Damm <[email protected]>

4 files changed, 73 insertions, 0 deletions

diff --git a/board/renesas/genmai/Kconfig b/board/renesas/genmai/Kconfig
new file mode 100644
index 00000000000..4e67a9b325a
--- /dev/null
+++ b/board/renesas/genmai/Kconfig
@@ -0,0 +1,12 @@
+if TARGET_GENMAI
+
+config SYS_BOARD
+	default "genmai"
+
+config SYS_VENDOR
+	default "renesas"
+
+config SYS_CONFIG_NAME
+	default "genmai"
+
+endif
diff --git a/board/renesas/genmai/MAINTAINERS b/board/renesas/genmai/MAINTAINERS
new file mode 100644
index 00000000000..1f1c2944632
--- /dev/null
+++ b/board/renesas/genmai/MAINTAINERS
@@ -0,0 +1,5 @@
+GENMAI BOARD
+M:	Magnus Damm <[email protected]>
+S:	Maintained
+F:	arch/arm/dts/r7s72100*
+N:	genmai
diff --git a/board/renesas/genmai/Makefile b/board/renesas/genmai/Makefile
new file mode 100644
index 00000000000..73f5e45affd
--- /dev/null
+++ b/board/renesas/genmai/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2025 Magnus Damm <[email protected]>
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-y	:= genmai.o
diff --git a/board/renesas/genmai/genmai.c b/board/renesas/genmai/genmai.c
new file mode 100644
index 00000000000..8153aed15e3
--- /dev/null
+++ b/board/renesas/genmai/genmai.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2025 Magnus Damm <[email protected]>
+ */
+
+#include <init.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+
+#define RZA1_BCR_BASE	0x3FFFC000
+#define CS0BCR		(RZA1_BCR_BASE + 0x04)
+#define CS0WCR		(RZA1_BCR_BASE + 0x28)
+#define CS1BCR		(RZA1_BCR_BASE + 0x08)
+#define CS1WCR		(RZA1_BCR_BASE + 0x2c)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int board_init(void)
+{
+	gd->bd->bi_boot_params = CFG_SYS_SDRAM_BASE + 0x100;
+
+	/* setup NOR Flash on CS0 and CS1 */
+	writel(0x00000b40, CS0WCR);
+	writel(0x10000c00, CS0BCR);
+	writel(0x00000b40, CS1WCR);
+	writel(0x10000c00, CS1BCR);
+	return 0;
+}
+
+/*
+ * The Genmai DT will most likely contain memory nodes describing the external
+ * SDRAM memory connected to CS2 and CS3, however we do not yet have any code
+ * in U-Boot to setup the memory controller. For now ignore DT and make use of
+ * the RZ/A1H on-chip memory which is 10 MiB at CFG_SYS_SDRAM_BASE.
+ */
+
+int dram_init(void)
+{
+	gd->ram_base = CFG_SYS_SDRAM_BASE;
+	gd->ram_size = 10 << 20;
+	return 0;
+}
+
+int dram_init_banksize(void)
+{
+	gd->bd->bi_dram[0].start = gd->ram_base;
+	gd->bd->bi_dram[0].size = gd->ram_size;
+	return 0;
+}