boston: Introduce support for the MIPS Boston development board

This patch introduces support for building U-Boot to run on the MIPS
Boston development board. This is a board built around an FPGA & an
Intel EG20T Platform Controller Hub, used largely as part of the
development of new CPUs and their software support. It is essentially
the successor to the older MIPS Malta board.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

arch/mips/Kconfig

@@ -75,6 +75,23 @@ config MACH_PIC32
 	select OF_CONTROL
 	select DM
 
+config TARGET_BOSTON
+	bool "Support Boston"
+	select DM
+	select DM_SERIAL
+	select OF_CONTROL
+	select MIPS_CM
+	select MIPS_L1_CACHE_SHIFT_6
+	select MIPS_L2_CACHE
+	select SUPPORTS_BIG_ENDIAN
+	select SUPPORTS_LITTLE_ENDIAN
+	select SUPPORTS_CPU_MIPS32_R1
+	select SUPPORTS_CPU_MIPS32_R2
+	select SUPPORTS_CPU_MIPS32_R6
+	select SUPPORTS_CPU_MIPS64_R1
+	select SUPPORTS_CPU_MIPS64_R2
+	select SUPPORTS_CPU_MIPS64_R6
+
 config TARGET_XILFPGA
 	bool "Support Imagination Xilfpga"
 	select OF_CONTROL
@@ -92,6 +109,7 @@ config TARGET_XILFPGA
 endchoice
 
 source "board/dbau1x00/Kconfig"
+source "board/imgtec/boston/Kconfig"
 source "board/imgtec/malta/Kconfig"
 source "board/imgtec/xilfpga/Kconfig"
 source "board/micronas/vct/Kconfig"

arch/mips/dts/Makefile

@@ -4,6 +4,7 @@
 
 dtb-$(CONFIG_TARGET_AP121) += ap121.dtb
 dtb-$(CONFIG_TARGET_AP143) += ap143.dtb
+dtb-$(CONFIG_TARGET_BOSTON) += img,boston.dtb
 dtb-$(CONFIG_TARGET_MALTA) += mti,malta.dtb
 dtb-$(CONFIG_TARGET_PIC32MZDASK) += pic32mzda_sk.dtb
 dtb-$(CONFIG_TARGET_XILFPGA) += nexys4ddr.dtb

arch/mips/dts/img,boston.dts

@@ -0,0 +1,222 @@
+/dts-v1/;
+
+#include <dt-bindings/clock/boston-clock.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/mips-gic.h>
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "img,boston";
+
+	chosen {
+		stdout-path = &uart0;
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "img,mips";
+			reg = <0>;
+			clocks = <&clk_boston BOSTON_CLK_CPU>;
+		};
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x00000000 0x10000000>;
+	};
+
+	gic: interrupt-controller {
+		compatible = "mti,gic";
+
+		interrupt-controller;
+		#interrupt-cells = <3>;
+
+		timer {
+			compatible = "mti,gic-timer";
+			interrupts = <GIC_LOCAL 1 IRQ_TYPE_NONE>;
+			clocks = <&clk_boston BOSTON_CLK_CPU>;
+		};
+	};
+
+	pci0: pci@10000000 {
+		status = "disabled";
+		compatible = "xlnx,axi-pcie-host-1.00.a";
+		device_type = "pci";
+		reg = <0x10000000 0x2000000>;
+
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SHARED 2 IRQ_TYPE_LEVEL_HIGH>;
+
+		ranges = <0x02000000 0 0x40000000
+			  0x40000000 0 0x40000000>;
+
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-map = <0 0 0 1 &pci0_intc 0>,
+				<0 0 0 2 &pci0_intc 1>,
+				<0 0 0 3 &pci0_intc 2>,
+				<0 0 0 4 &pci0_intc 3>;
+
+		pci0_intc: interrupt-controller {
+			interrupt-controller;
+			#address-cells = <0>;
+			#interrupt-cells = <1>;
+		};
+	};
+
+	pci1: pci@12000000 {
+		status = "disabled";
+		compatible = "xlnx,axi-pcie-host-1.00.a";
+		device_type = "pci";
+		reg = <0x12000000 0x2000000>;
+
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SHARED 1 IRQ_TYPE_LEVEL_HIGH>;
+
+		ranges = <0x02000000 0 0x20000000
+			  0x20000000 0 0x20000000>;
+
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-map = <0 0 0 1 &pci1_intc 0>,
+				<0 0 0 2 &pci1_intc 1>,
+				<0 0 0 3 &pci1_intc 2>,
+				<0 0 0 4 &pci1_intc 3>;
+
+		pci1_intc: interrupt-controller {
+			interrupt-controller;
+			#address-cells = <0>;
+			#interrupt-cells = <1>;
+		};
+	};
+
+	pci2: pci@14000000 {
+		compatible = "xlnx,axi-pcie-host-1.00.a";
+		device_type = "pci";
+		reg = <0x14000000 0x2000000>;
+
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SHARED 0 IRQ_TYPE_LEVEL_HIGH>;
+
+		ranges = <0x02000000 0 0x16000000
+			  0x16000000 0 0x100000>;
+
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-map = <0 0 0 1 &pci2_intc 0>,
+				<0 0 0 2 &pci2_intc 1>,
+				<0 0 0 3 &pci2_intc 2>,
+				<0 0 0 4 &pci2_intc 3>;
+
+		pci2_intc: interrupt-controller {
+			interrupt-controller;
+			#address-cells = <0>;
+			#interrupt-cells = <1>;
+		};
+
+		pci2_root@0,0,0 {
+			compatible = "pci10ee,7021";
+			reg = <0x00000000 0 0 0 0>;
+
+			#address-cells = <3>;
+			#size-cells = <2>;
+			#interrupt-cells = <1>;
+
+			eg20t_bridge@1,0,0 {
+				compatible = "pci8086,8800";
+				reg = <0x00010000 0 0 0 0>;
+
+				#address-cells = <3>;
+				#size-cells = <2>;
+				#interrupt-cells = <1>;
+
+				eg20t_mac@2,0,1 {
+					compatible = "pci8086,8802";
+					reg = <0x00020100 0 0 0 0>;
+					phy-reset-gpios = <&eg20t_gpio 6 GPIO_ACTIVE_LOW>;
+				};
+
+				eg20t_gpio: eg20t_gpio@2,0,2 {
+					compatible = "pci8086,8803";
+					reg = <0x00020200 0 0 0 0>;
+
+					gpio-controller;
+					#gpio-cells = <2>;
+				};
+
+				eg20t_i2c@2,12,2 {
+					compatible = "pci8086,8817";
+					reg = <0x00026200 0 0 0 0>;
+
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					rtc@0x68 {
+						compatible = "st,m41t81s";
+						reg = <0x68>;
+					};
+				};
+			};
+		};
+	};
+
+	plat_regs: system-controller@17ffd000 {
+		compatible = "img,boston-platform-regs", "syscon";
+		reg = <0x17ffd000 0x1000>;
+		u-boot,dm-pre-reloc;
+	};
+
+	clk_boston: clock {
+		compatible = "img,boston-clock";
+		#clock-cells = <1>;
+		regmap = <&plat_regs>;
+		u-boot,dm-pre-reloc;
+	};
+
+	reboot: syscon-reboot {
+		compatible = "syscon-reboot";
+		regmap = <&plat_regs>;
+		offset = <0x10>;
+		mask = <0x10>;
+	};
+
+	uart0: uart@17ffe000 {
+		compatible = "ns16550a";
+		reg = <0x17ffe000 0x1000>;
+		reg-shift = <2>;
+		reg-io-width = <4>;
+
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SHARED 3 IRQ_TYPE_LEVEL_HIGH>;
+
+		clocks = <&clk_boston BOSTON_CLK_SYS>;
+
+		u-boot,dm-pre-reloc;
+	};
+
+	lcd: lcd@17fff000 {
+		compatible = "img,boston-lcd";
+		reg = <0x17fff000 0x8>;
+	};
+
+	flash@18000000 {
+		compatible = "cfi-flash";
+		reg = <0x18000000 0x8000000>;
+		bank-width = <2>;
+	};
+};

board/imgtec/boston/Kconfig

@@ -0,0 +1,16 @@
+if TARGET_BOSTON
+
+config SYS_BOARD
+	default "boston"
+
+config SYS_VENDOR
+	default "imgtec"
+
+config SYS_CONFIG_NAME
+	default "boston"
+
+config SYS_TEXT_BASE
+	default 0x9fc00000 if 32BIT
+	default 0xffffffff9fc00000 if 64BIT
+
+endif

board/imgtec/boston/MAINTAINERS

@@ -0,0 +1,6 @@
+BOSTON BOARD
+M:	Paul Burton <paul.burton@imgtec.com>
+S:	Maintained
+F:	board/imgtec/boston/
+F:	include/configs/boston.h
+F:	configs/boston_defconfig

board/imgtec/boston/Makefile

@@ -0,0 +1,9 @@
+#
+# Copyright (C) 2016 Imagination Technologies
+#
+# SPDX-License-Identifier:	GPL-2.0
+#
+
+obj-y += checkboard.o
+obj-y += ddr.o
+obj-y += lowlevel_init.o

board/imgtec/boston/boston-lcd.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef __BOARD_BOSTON_LCD_H__
+#define __BOARD_BOSTON_LCD_H__
+
+/**
+ * lowlevel_display() - Display a message on Boston's LCD
+ * @msg: The string to display
+ *
+ * Display the string @msg on the 7 character LCD display of the Boston board.
+ * This is typically used for debug or to present some form of status
+ * indication to the user, allowing faults to be identified when things go
+ * wrong early enough that the UART isn't up.
+ */
+void lowlevel_display(const char msg[static 8]);
+
+#endif /* __BOARD_BOSTON_LCD_H__ */

board/imgtec/boston/boston-regs.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef __BOARD_BOSTON_REGS_H__
+#define __BOARD_BOSTON_REGS_H__
+
+#include <asm/addrspace.h>
+
+#define BOSTON_PLAT_BASE		CKSEG1ADDR(0x17ffd000)
+#define BOSTON_LCD_BASE			CKSEG1ADDR(0x17fff000)
+
+/*
+ * Platform Register Definitions
+ */
+#define BOSTON_PLAT_CORE_CL		(BOSTON_PLAT_BASE + 0x04)
+
+#define BOSTON_PLAT_DDR3STAT		(BOSTON_PLAT_BASE + 0x14)
+# define BOSTON_PLAT_DDR3STAT_CALIB	(1 << 2)
+
+#define BOSTON_PLAT_DDRCONF0		(BOSTON_PLAT_BASE + 0x38)
+# define BOSTON_PLAT_DDRCONF0_SIZE	(0xf << 0)
+
+#endif /* __BOARD_BOSTON_REGS_H__ */

board/imgtec/boston/checkboard.c

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+
+#include <asm/io.h>
+#include <asm/mipsregs.h>
+
+#include "boston-lcd.h"
+#include "boston-regs.h"
+
+int checkboard(void)
+{
+	u32 changelist;
+
+	lowlevel_display("U-boot  ");
+
+	printf("Board: MIPS Boston\n");
+
+	printf("CPU:   0x%08x", read_c0_prid());
+	changelist = __raw_readl((uint32_t *)BOSTON_PLAT_CORE_CL);
+	if (changelist > 1)
+		printf(" cl%x", changelist);
+	putc('\n');
+
+	return 0;
+}

board/imgtec/boston/ddr.c

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+
+#include <asm/io.h>
+
+#include "boston-regs.h"
+
+phys_size_t initdram(int board_type)
+{
+	u32 ddrconf0 = __raw_readl((uint32_t *)BOSTON_PLAT_DDRCONF0);
+
+	return (phys_size_t)(ddrconf0 & BOSTON_PLAT_DDRCONF0_SIZE) << 30;
+}
+
+ulong board_get_usable_ram_top(ulong total_size)
+{
+	DECLARE_GLOBAL_DATA_PTR;
+
+	if (gd->ram_top < CONFIG_SYS_SDRAM_BASE) {
+		/* 2GB wrapped around to 0 */
+		return CKSEG0ADDR(256 << 20);
+	}
+
+	return min_t(unsigned long, gd->ram_top, CKSEG0ADDR(256 << 20));
+}

board/imgtec/boston/lowlevel_init.S

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <config.h>
+
+#include <asm/addrspace.h>
+#include <asm/asm.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+
+#include "boston-regs.h"
+
+.data
+
+msg_ddr_cal:	.ascii "DDR Cal "
+msg_ddr_ok:	.ascii "DDR OK  "
+
+.text
+
+LEAF(lowlevel_init)
+	move	s0, ra
+
+	PTR_LA	a0, msg_ddr_cal
+	bal	lowlevel_display
+
+	PTR_LI	t0, BOSTON_PLAT_DDR3STAT
+1:	lw	t1, 0(t0)
+	andi	t1, t1, BOSTON_PLAT_DDR3STAT_CALIB
+	beqz	t1, 1b
+
+	PTR_LA	a0, msg_ddr_ok
+	bal	lowlevel_display
+
+	move	v0, zero
+	jr	s0
+	END(lowlevel_init)
+
+LEAF(lowlevel_display)
+	.set	push
+	.set	noat
+	PTR_LI	AT, BOSTON_LCD_BASE
+#ifdef CONFIG_64BIT
+	ld	k1, 0(a0)
+	sd	k1, 0(AT)
+#else
+	lw	k1, 0(a0)
+	sw	k1, 0(AT)
+	lw	k1, 4(a0)
+	sw	k1, 4(AT)
+#endif
+	.set	pop
+1:	jr	ra
+	END(lowlevel_display)

configs/boston32r2_defconfig

@@ -0,0 +1,41 @@
+CONFIG_MIPS=y
+CONFIG_TARGET_BOSTON=y
+CONFIG_SYS_TEXT_BASE=0x9fc00000
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_DEFAULT_DEVICE_TREE="img,boston"
+CONFIG_FIT=y
+CONFIG_FIT_VERBOSE=y
+CONFIG_FIT_BEST_MATCH=y
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_PROMPT="boston # "
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_IMLS is not set
+CONFIG_CMD_GREPENV=y
+CONFIG_CMD_MEMTEST=y
+# CONFIG_CMD_LOADB is not set
+# CONFIG_CMD_LOADS is not set
+# CONFIG_CMD_FPGA is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_SNTP=y
+CONFIG_CMD_DNS=y
+CONFIG_CMD_LINK_LOCAL=y
+CONFIG_CMD_TIME=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_EMBED=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_CLK=y
+CONFIG_MTD=y
+CONFIG_CFI_FLASH=y
+CONFIG_DM_ETH=y
+CONFIG_PCH_GBE=y
+CONFIG_DM_PCI=y
+CONFIG_PCI_XILINX=y
+CONFIG_SYS_NS16550=y
+CONFIG_LZ4=y

configs/boston32r2el_defconfig

@@ -0,0 +1,42 @@
+CONFIG_MIPS=y
+CONFIG_TARGET_BOSTON=y
+CONFIG_SYS_TEXT_BASE=0x9fc00000
+CONFIG_SYS_LITTLE_ENDIAN=y
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_DEFAULT_DEVICE_TREE="img,boston"
+CONFIG_FIT=y
+CONFIG_FIT_VERBOSE=y
+CONFIG_FIT_BEST_MATCH=y
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_PROMPT="boston # "
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_IMLS is not set
+CONFIG_CMD_GREPENV=y
+CONFIG_CMD_MEMTEST=y
+# CONFIG_CMD_LOADB is not set
+# CONFIG_CMD_LOADS is not set
+# CONFIG_CMD_FPGA is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_SNTP=y
+CONFIG_CMD_DNS=y
+CONFIG_CMD_LINK_LOCAL=y
+CONFIG_CMD_TIME=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_EMBED=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_CLK=y
+CONFIG_MTD=y
+CONFIG_CFI_FLASH=y
+CONFIG_DM_ETH=y
+CONFIG_PCH_GBE=y
+CONFIG_DM_PCI=y
+CONFIG_PCI_XILINX=y
+CONFIG_SYS_NS16550=y
+CONFIG_LZ4=y

configs/boston64r2_defconfig

@@ -0,0 +1,41 @@
+CONFIG_MIPS=y
+CONFIG_TARGET_BOSTON=y
+CONFIG_CPU_MIPS64_R2=y
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_DEFAULT_DEVICE_TREE="img,boston"
+CONFIG_FIT=y
+CONFIG_FIT_VERBOSE=y
+CONFIG_FIT_BEST_MATCH=y
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_PROMPT="boston # "
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_IMLS is not set
+CONFIG_CMD_GREPENV=y
+CONFIG_CMD_MEMTEST=y
+# CONFIG_CMD_LOADB is not set
+# CONFIG_CMD_LOADS is not set
+# CONFIG_CMD_FPGA is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_SNTP=y
+CONFIG_CMD_DNS=y
+CONFIG_CMD_LINK_LOCAL=y
+CONFIG_CMD_TIME=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_EMBED=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_CLK=y
+CONFIG_MTD=y
+CONFIG_CFI_FLASH=y
+CONFIG_DM_ETH=y
+CONFIG_PCH_GBE=y
+CONFIG_DM_PCI=y
+CONFIG_PCI_XILINX=y
+CONFIG_SYS_NS16550=y
+CONFIG_LZ4=y

configs/boston64r2el_defconfig

@@ -0,0 +1,42 @@
+CONFIG_MIPS=y
+CONFIG_TARGET_BOSTON=y
+CONFIG_SYS_LITTLE_ENDIAN=y
+CONFIG_CPU_MIPS64_R2=y
+# CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
+# CONFIG_MIPS_BOOT_ENV_LEGACY is not set
+CONFIG_MIPS_BOOT_FDT=y
+CONFIG_DEFAULT_DEVICE_TREE="img,boston"
+CONFIG_FIT=y
+CONFIG_FIT_VERBOSE=y
+CONFIG_FIT_BEST_MATCH=y
+CONFIG_OF_STDOUT_VIA_ALIAS=y
+CONFIG_HUSH_PARSER=y
+CONFIG_SYS_PROMPT="boston # "
+# CONFIG_CMD_ELF is not set
+# CONFIG_CMD_IMLS is not set
+CONFIG_CMD_GREPENV=y
+CONFIG_CMD_MEMTEST=y
+# CONFIG_CMD_LOADB is not set
+# CONFIG_CMD_LOADS is not set
+# CONFIG_CMD_FPGA is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_SNTP=y
+CONFIG_CMD_DNS=y
+CONFIG_CMD_LINK_LOCAL=y
+CONFIG_CMD_TIME=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_EMBED=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_CLK=y
+CONFIG_MTD=y
+CONFIG_CFI_FLASH=y
+CONFIG_DM_ETH=y
+CONFIG_PCH_GBE=y
+CONFIG_DM_PCI=y
+CONFIG_PCI_XILINX=y
+CONFIG_SYS_NS16550=y
+CONFIG_LZ4=y

doc/README.boston

@@ -0,0 +1,58 @@
+MIPS Boston Development Board
+
+---------
+  About
+---------
+
+The MIPS Boston development board is built around an FPGA & 3 PCIe controllers,
+one of which is connected to an Intel EG20T Platform Controller Hub which
+provides most connectivity to the board. It is used during the development &
+testing of both new CPUs and the software support for them. It is essentially
+the successor of the older MIPS Malta board.
+
+--------
+  QEMU
+--------
+
+U-Boot can be run on a currently out-of-tree branch of QEMU with support for
+the Boston board added. This QEMU code can currently be found in the "boston"
+branch of git://git.linux-mips.org/pub/scm/paul/qemu.git and used like so:
+
+  $ git clone git://git.linux-mips.org/pub/scm/paul/qemu.git -b boston
+  $ cd qemu
+  $ ./configure --target-list=mips64el-softmmu
+  $ make
+  $ ./mips64el-softmmu/qemu-system-mips64el -M boston -m 2G \
+      -bios u-boot.bin -serial stdio
+
+Please note that QEMU will default to emulating the I6400 CPU which implements
+the MIPS64r6 ISA, and at the time of writing doesn't implement any earlier CPUs
+with support for the CPS features the Boston board relies upon. You will
+therefore need to configure U-Boot to build for MIPSr6 in order to obtain a
+binary that will work in QEMU.
+
+-------------
+  Toolchain
+-------------
+
+If building for MIPSr6 then you will need a toolchain including GCC 5.x or
+newer, or the Codescape toolchain available for download from Imagination
+Technologies:
+
+  http://codescape-mips-sdk.imgtec.com/components/toolchain/2015.06-05/
+
+The "IMG GNU Linux Toolchain" is capable of building for all current MIPS ISAs,
+architecture revisions & both endiannesses.
+
+--------
+  TODO
+--------
+
+  - AHCI support
+  - CPU driver
+  - Exception handling (+UHI?)
+  - Flash support
+  - IOCU support
+  - L2 cache support
+  - More general LCD display driver
+  - Multi-arch-variant multi-endian fat binary

include/configs/boston.h

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef __CONFIGS_BOSTON_H__
+#define __CONFIGS_BOSTON_H__
+
+/*
+ * General board configuration
+ */
+#define CONFIG_DISPLAY_BOARDINFO
+
+/*
+ * CPU
+ */
+#define CONFIG_SYS_MIPS_TIMER_FREQ	30000000
+
+/*
+ * PCI
+ */
+#define CONFIG_PCI
+#define CONFIG_PCI_PNP
+#define CONFIG_CMD_PCI
+
+/*
+ * Memory map
+ */
+#ifdef CONFIG_64BIT
+# define CONFIG_SYS_SDRAM_BASE		0xffffffff80000000
+#else
+# define CONFIG_SYS_SDRAM_BASE		0x80000000
+#endif
+
+#define CONFIG_SYS_INIT_SP_OFFSET	0x400000
+
+#define CONFIG_SYS_MONITOR_BASE		CONFIG_SYS_TEXT_BASE
+
+#define CONFIG_SYS_LOAD_ADDR		(CONFIG_SYS_SDRAM_BASE + 0x100000)
+
+#define CONFIG_SYS_MEMTEST_START	(CONFIG_SYS_SDRAM_BASE + 0)
+#define CONFIG_SYS_MEMTEST_END		(CONFIG_SYS_SDRAM_BASE + 0x10000000)
+
+#define CONFIG_SYS_MALLOC_LEN		(256 * 1024)
+
+/*
+ * Console
+ */
+#define CONFIG_SYS_MAXARGS		16
+#define CONFIG_SYS_CBSIZE		256
+#define CONFIG_SYS_PBSIZE		(CONFIG_SYS_CBSIZE + \
+					 sizeof(CONFIG_SYS_PROMPT) + 16)
+#define CONFIG_SYS_LONGHELP
+#define CONFIG_BAUDRATE			115200
+
+/*
+ * Flash
+ */
+#define CONFIG_FLASH_CFI_DRIVER
+#define CONFIG_SYS_FLASH_CFI
+#define CONFIG_SYS_FLASH_PROTECTION
+#define CONFIG_SYS_FLASH_USE_BUFFER_WRITE
+#define CONFIG_SYS_MAX_FLASH_BANKS_DETECT	1
+#define CONFIG_SYS_MAX_FLASH_SECT		1024
+
+/*
+ * Environment
+ */
+#define CONFIG_ENV_IS_IN_FLASH
+#define CONFIG_ENV_SECT_SIZE		0x20000
+#define CONFIG_ENV_SIZE			CONFIG_ENV_SECT_SIZE
+#ifdef CONFIG_64BIT
+# define CONFIG_ENV_ADDR \
+	(0xffffffffb8000000 + (128 << 20) - CONFIG_ENV_SIZE)
+#else
+# define CONFIG_ENV_ADDR \
+	(0xb8000000 + (128 << 20) - CONFIG_ENV_SIZE)
+#endif
+
+#endif /* __CONFIGS_BOSTON_H__ */