board: Add new Broadcom Northstar board

This adds a simple Northstar "BRCMNS" board to be used with
the BCM4708x and BCM5301x chips.

The main intention is to use this with the D-Link DIR-890L
and DIR-885L routers for loading the kernel into RAM from
NAND memory using the BCH-1 ECC and using the separately
submitted SEAMA load command, so we are currently not adding
support for things such as networking.

The DTS file is a multiplatform NorthStar board, designed to
be usable with several NorthStar designs by avoiding any
particulars not related to the operation of U-Boot.

If other board need other ECC for example, they need to
create a separate DTS file and augment the code, but I don't
know if any other users will turn up.

Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/Kconfig

@@ -2285,6 +2285,7 @@ source "board/Marvell/octeontx2/Kconfig"
 source "board/armltd/vexpress/Kconfig"
 source "board/armltd/vexpress64/Kconfig"
 source "board/cortina/presidio-asic/Kconfig"
+source "board/broadcom/bcmns/Kconfig"
 source "board/broadcom/bcmns3/Kconfig"
 source "board/cavium/thunderx/Kconfig"
 source "board/eets/pdu001/Kconfig"

arch/arm/dts/Makefile

@@ -1200,6 +1200,8 @@ dtb-$(CONFIG_ARCH_BCM283X) += \
 	bcm2837-rpi-cm3-io3.dtb \
 	bcm2711-rpi-4-b.dtb
 
+dtb-$(CONFIG_TARGET_BCMNS) += ns-board.dtb
+
 dtb-$(CONFIG_TARGET_BCMNS3) += ns3-board.dtb
 
 dtb-$(CONFIG_ARCH_BCMSTB) += bcm7xxx.dtb

arch/arm/dts/ns-board.dts

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier:      GPL-2.0+
+
+/dts-v1/;
+
+#include "bcm5301x.dtsi"
+
+/ {
+	/*
+	 * The Northstar does not have a proper fallback compatible, but
+	 * these basic chips will suffice.
+	 */
+	model = "Northstar model";
+	compatible = "brcm,bcm47094", "brcm,bcm4708";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&gic>;
+
+	memory {
+		device_type = "memory";
+		reg = <0x00000000 0x08000000>,
+		      <0x88000000 0x08000000>;
+	};
+
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	nand-controller@18028000 {
+		nandcs: nand@0 {
+			compatible = "brcm,nandcs";
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			/*
+			 * Same as using the bcm5301x-nand-cs0-bch1.dtsi
+			 * include from the Linux kernel.
+			 */
+			nand-ecc-algo = "bch";
+			nand-ecc-strength = <1>;
+			nand-ecc-step-size = <512>;
+
+			partitions {
+				compatible = "brcm,bcm947xx-cfe-partitions";
+			};
+		};
+	};
+};
+
+&uart0 {
+	clock-frequency = <125000000>;
+	status = "okay";
+};

board/broadcom/bcmns/Kconfig

@@ -0,0 +1,12 @@
+if TARGET_BCMNS
+
+config SYS_BOARD
+	default "bcmns"
+
+config SYS_VENDOR
+	default "broadcom"
+
+config SYS_CONFIG_NAME
+	default "bcmns"
+
+endif

board/broadcom/bcmns/MAINTAINERS

@@ -0,0 +1,6 @@
+BCMNS BOARD
+M:	Linus Walleij <linus.walleij@linaro.org>
+S:	Maintained
+F:	board/broadcom/bcmnsp/
+F:	configs/bcmnsp_defconfig
+F:	include/configs/bcmnsp.h

board/broadcom/bcmns/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+obj-y	:= ns.o

board/broadcom/bcmns/ns.c

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Broadcom Northstar generic board set-up code
+ * Copyright (C) 2023 Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <init.h>
+#include <log.h>
+#include <ram.h>
+#include <serial.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <asm/armv7m.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int dram_init(void)
+{
+	return fdtdec_setup_mem_size_base();
+}
+
+int dram_init_banksize(void)
+{
+	return fdtdec_setup_memory_banksize();
+}
+
+int board_late_init(void)
+{
+	/* LEDs etc can be initialized here */
+	return 0;
+}
+
+int board_init(void)
+{
+	return 0;
+}
+
+void reset_cpu(void)
+{
+}
+
+int print_cpuinfo(void)
+{
+	printf("BCMNS Northstar SoC\n");
+	return 0;
+}
+
+int misc_init_r(void)
+{
+	return 0;
+}
+
+int ft_board_setup(void *fdt, struct bd_info *bd)
+{
+	printf("Northstar board setup: DTB at 0x%08lx\n", (ulong)fdt);
+	return 0;
+}
+

configs/bcmns_defconfig

@@ -0,0 +1,41 @@
+CONFIG_ARM=y
+CONFIG_TARGET_BCMNS=y
+CONFIG_TEXT_BASE=0x00008000
+CONFIG_SYS_MALLOC_LEN=0x2000000
+CONFIG_SYS_MALLOC_F_LEN=0x8000
+CONFIG_NR_DRAM_BANKS=2
+CONFIG_DEFAULT_DEVICE_TREE="ns-board"
+CONFIG_IDENT_STRING="Broadcom Northstar"
+CONFIG_SYS_LOAD_ADDR=0x00008000
+CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
+CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x00100000
+# CONFIG_BOOTSTD is not set
+CONFIG_AUTOBOOT_KEYED=y
+CONFIG_AUTOBOOT_PROMPT="Boot Northstar system in %d seconds\n"
+CONFIG_BOOTDELAY=1
+CONFIG_USE_BOOTCOMMAND=y
+CONFIG_BOOTCOMMAND="run bootcmd_dlink_dir8xxl"
+CONFIG_SYS_PROMPT="northstar> "
+CONFIG_ENV_VARS_UBOOT_CONFIG=y
+CONFIG_OF_BOARD_SETUP=y
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_MAXARGS=64
+CONFIG_CMD_SEAMA=y
+CONFIG_CMD_BOOTZ=y
+CONFIG_CMD_CACHE=y
+CONFIG_OF_EMBED=y
+CONFIG_USE_HOSTNAME=y
+CONFIG_HOSTNAME="NS"
+CONFIG_CLK=y
+CONFIG_MTD=y
+CONFIG_DM_MTD=y
+CONFIG_MTD_RAW_NAND=y
+CONFIG_NAND_BRCMNAND=y
+CONFIG_SYS_NAND_ONFI_DETECTION=y
+CONFIG_CMD_NAND=y
+CONFIG_DM_SERIAL=y
+CONFIG_SYS_NS16550=y
+# CONFIG_NET is not set
+# CONFIG_EFI_LOADER is not set

doc/board/broadcom/index.rst

@@ -9,3 +9,4 @@ Broadcom
 
    bcm7xxx
    raspberrypi
+   northstar

doc/board/broadcom/northstar.rst

@@ -0,0 +1,44 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright (C) 2023 Linus Walleij <linus.walleij@linaro.org>
+
+Broadcom Northstar Boards
+=========================
+
+This document describes how to use U-Boot on the Broadcom Northstar
+boards, comprised of the Cortex A9 ARM-based BCM470x and BCM5301x SoCs. These
+were introduced in 2012-2013 and some of them are also called StrataGX.
+
+Northstar is part of the iProc SoC family.
+
+A good overview of these boards can be found in Jon Mason's presentation
+"Enabling New Hardware in U-Boot" where the difference between Northstar
+and Northstar Plus and Northstar 2 (Aarch64) is addressed.
+
+The ROM in the Northstar SoC will typically look into NOR flash memory
+for a boot loader, and the way this works is undocumented. It should be
+possible to execute U-Boot as the first binary from the NOR flash but
+this usage path is unexplored. Please add information if you know more.
+
+D-Link Boards
+-------------
+
+When we use U-Boot with D-Link routers, the NOR flash has a boot loader
+and web server that can re-flash the bigger NAND flash memory for object
+code in the SEAMA format, so on these platforms U-Boot is converted into
+a SEAMA binary and installed in the SoC using the flash tool resident in
+the NOR flash. Details can be found in the OpenWrt project codebase.
+
+Configure
+---------
+
+.. code-block:: console
+
+	$ make CROSS_COMPILE=${CROSS_COMPILE} bcmns_defconfig
+
+Build
+-----
+
+.. code-block:: console
+
+	$ make CROSS_COMPILE=${CROSS_COMPILE}
+	$ ${CROSS_COMPILE}strip u-boot

include/configs/bcmns.h

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __BCM_NS_H
+#define __BCM_NS_H
+
+#include <linux/sizes.h>
+
+/* Physical Memory Map */
+#define V2M_BASE			0x00000000
+#define PHYS_SDRAM_1			V2M_BASE
+
+#define CFG_SYS_SDRAM_BASE		PHYS_SDRAM_1
+
+/* Called "periph_clk" in Linux, used by the global timer */
+#define CFG_SYS_HZ_CLOCK		500000000
+
+/* Called "iprocslow" in Linux */
+#define CFG_SYS_NS16550_CLK		125000000
+
+/* console configuration */
+#define CONSOLE_ARGS "console_args=console=ttyS0,115200n8\0"
+#define MAX_CPUS "max_cpus=maxcpus=2\0"
+#define EXTRA_ARGS "extra_args=earlycon=uart8250,mmio32,0x18000300\0"
+
+#define BASE_ARGS "${console_args} ${extra_args} ${pcie_args}"	\
+		  " ${max_cpus}  ${log_level} ${reserved_mem}"
+#define SETBOOTARGS "setbootargs=setenv bootargs " BASE_ARGS "\0"
+
+#define KERNEL_LOADADDR_CFG \
+	"loadaddr=0x01000000\0" \
+	"dtb_loadaddr=0x02000000\0"
+
+/*
+ * Hardcoded for the only boards we support, if you add more
+ * boards, add a more clever bootcmd!
+ */
+#define NS_BOOTCMD "bootcmd_dlink_dir8xxl=seama 0x00fe0000; go 0x01000000"
+
+#define ARCH_ENV_SETTINGS \
+	CONSOLE_ARGS \
+	MAX_CPUS \
+	EXTRA_ARGS \
+	KERNEL_LOADADDR_CFG \
+	NS_BOOTCMD
+
+#define CFG_EXTRA_ENV_SETTINGS \
+	ARCH_ENV_SETTINGS
+
+#endif /* __BCM_NS_H */