board: riscv: add openpiton-riscv64 SoC support

This patch adds openpiton-riscv64 SOC support. In particular, this
board supports a standard bootflow through zsbl->u-boot SPL->
opensbi->u-boot proper->Linux. There are separate defconfigs for
building u-boot SPL and u-boot proper

Signed-off-by: Tianrui Wei <tianrui-wei@outlook.com>
Signed-off-by: Jonathan Balkind <jbalkind@ucsb.edu>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/doc/board/openpiton/index.rst b/doc/board/openpiton/index.rst
new file mode 100644
index 0000000..c469102
--- /dev/null
+++ b/doc/board/openpiton/index.rst
@@ -0,0 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+OpenPiton
+=========
+
+.. toctree::
+   :maxdepth: 2
+
+   riscv64
diff --git a/doc/board/openpiton/riscv64.rst b/doc/board/openpiton/riscv64.rst
new file mode 100644
index 0000000..253b37c
--- /dev/null
+++ b/doc/board/openpiton/riscv64.rst
@@ -0,0 +1,376 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Openpiton RISC-V SoC
+====================
+
+OpenPiton RISC-V SoC
+--------------------
+OpenPiton is an open source, manycore processor and research platform. It is a
+tiled manycore framework scalable from one to 1/2 billion cores. It supports a
+number of ISAs including RISC-V with its P-Mesh cache coherence protocol and
+networks on chip. It is highly configurable in both core and uncore components.
+OpenPiton has been verified in both ASIC and multiple Xilinx FPGA prototypes
+running full-stack Debian linux.
+
+RISC-V Standard Bootflow
+-------------------------
+Currently, OpenPiton implements RISC-V standard bootflow in the following steps
+mover.S -> u-boot-spl -> opensbi -> u-boot -> Linux
+This board supports S-mode u-boot as well as M-mode SPL
+
+Building OpenPition
+---------------------
+If you'd like to build OpenPiton, please go to OpenPiton github repo
+(at https://github.com/PrincetonUniversity/openpiton) to build from the latest
+changes
+
+Building Images
+---------------------------
+
+SPL
+---
+
+1. Add the RISC-V toolchain to your PATH.
+2. Setup ARCH & cross compilation environment variable:
+
+.. code-block:: none
+
+	export CROSS_COMPILE=<riscv64 toolchain prefix>
+	export ARCH=riscv
+
+3. make openpiton_riscv64_spl_defconfig
+4. make
+
+U-Boot
+------
+
+1. Add the RISC-V toolchain to your PATH.
+2. Setup ARCH & cross compilation environment variable:
+
+.. code-block:: none
+
+	export CROSS_COMPILE=<riscv64 toolchain prefix>
+	export ARCH=riscv
+
+3. make openpiton_riscv64_defconfig
+4. make
+
+
+opensbi
+-------
+
+1. Add the RISC-V toolchain to your PATH.
+2. Setup ARCH & cross compilation environment variable:
+
+.. code-block:: none
+
+	export CROSS_COMPILE=<riscv64 toolchain prefix>
+	export ARCH=riscv
+
+3. Go to OpenSBI directory
+4. make PLATFORM=fpga/openpiton FW_PAYLOAD_PATH=<path to u-boot-nodtb.bin>
+
+
+Using fw_payload.bin with linux
+-------------------------------
+Put the generated fw_payload.bin into the /boot directory on the root filesystem,
+plug in the SD card, then flash the bitstream. Linux will boot automatically.
+
+Booting
+-------
+Once you plugin the sdcard and power up, you should see the U-Boot prompt.
+
+Sample Dual-core Debian boot log from OpenPiton
+-----------------------------------------------
+
+.. code-block:: none
+
+	Trying to boot from MMC1
+
+	OpenSBI v0.9-5-gd06cb61
+	____                    _____ ____ _____
+	/ __ \                  / ____|  _ \_   _|
+	| |  | |_ __   ___ _ __ | (___ | |_) || |
+	| |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
+	| |__| | |_) |  __/ | | |____) | |_) || |_
+	\____/| .__/ \___|_| |_|_____/|____/_____|
+	| |
+	|_|
+
+	Platform Name             : OPENPITON RISC-V
+	Platform Features         : timer,mfdeleg
+	Platform HART Count       : 3
+	Firmware Base             : 0x80000000
+	Firmware Size             : 104 KB
+	Runtime SBI Version       : 0.2
+
+	Domain0 Name              : root
+	Domain0 Boot HART         : 0
+	Domain0 HARTs             : 0*,1*,2*
+	Domain0 Region00          : 0x0000000080000000-0x000000008001ffff ()
+	Domain0 Region01          : 0x0000000000000000-0xffffffffffffffff (R,W,X)
+	Domain0 Next Address      : 0x0000000080200000
+	Domain0 Next Arg1         : 0x0000000082200000
+	Domain0 Next Mode         : S-mode
+	Domain0 SysReset          : yes
+
+	Boot HART ID              : 0
+	Boot HART Domain          : root
+	Boot HART ISA             : rv64imafdcsu
+	Boot HART Features        : scounteren,mcounteren
+	Boot HART PMP Count       : 0
+	Boot HART PMP Granularity : 0
+	Boot HART PMP Address Bits: 0
+	Boot HART MHPM Count      : 0
+	Boot HART MHPM Count      : 0
+	Boot HART MIDELEG         : 0x0000000000000222
+	Boot HART MEDELEG         : 0x000000000000b109
+
+
+	U-Boot 2021.01+ (Jun 12 2021 - 10:31:34 +0800)
+
+	DRAM:  1 GiB
+	MMC:   sdhci@f000000000: 0 (eMMC)
+	In:    uart@fff0c2c000
+	Out:   uart@fff0c2c000
+	Err:   uart@fff0c2c000
+	Hit any key to stop autoboot:  0
+	6492992 bytes read in 5310 ms (1.2 MiB/s)
+	## Flattened Device Tree blob at 86000000
+	Booting using the fdt blob at 0x86000000
+	Loading Device Tree to 00000000bfffa000, end 00000000bffff007 ... OK
+
+	Starting kernel ...
+
+	[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
+	[    0.000000] Linux version 5.6.0-rc4-gb9d34f7e294d-dirty
+	[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
+	[    0.000000] printk: bootconsole [sbi0] enabled
+	[    0.000000] Zone ranges:
+	[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000bfffffff]
+	[    0.000000]   Normal   empty
+	[    0.000000] Movable zone start for each node
+	[    0.000000] Early memory node ranges
+	[    0.000000]   node   0: [mem 0x0000000080200000-0x00000000bfffffff]
+	[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x00000000bfffffff]
+	[    0.000000] On node 0 totalpages: 261632
+	[    0.000000]   DMA32 zone: 4088 pages used for memmap
+	[    0.000000]   DMA32 zone: 0 pages reserved
+	[    0.000000]   DMA32 zone: 261632 pages, LIFO batch:63
+	[    0.000000] software IO TLB: mapped [mem 0xbaffa000-0xbeffa000] (64MB)
+	[    0.000000] SBI specification v0.2 detected
+	[    0.000000] SBI implementation ID=0x1 Version=0x9
+	[    0.000000] SBI v0.2 TIME extension detected
+	[    0.000000] SBI v0.2 IPI extension detected
+	[    0.000000] SBI v0.2 RFENCE extension detected
+	[    0.000000] SBI v0.2 HSM extension detected
+	[    0.000000] elf_hwcap is 0x112d
+	[    0.000000] percpu: Embedded 16 pages/cpu s25368 r8192 d31976 u65536
+	[    0.000000] pcpu-alloc: s25368 r8192 d31976 u65536 alloc=16*4096
+	[    0.000000] pcpu-alloc: [0] 0
+	[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 257544
+	[    0.000000] Kernel command line: earlycon=sbi root=/dev/piton_sd1
+	[    0.000000] Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)
+	[    0.000000] Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)
+	[    0.000000] Sorting __ex_table...
+	[    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
+	[    0.000000] Memory: 956252K/1046528K available (4357K kernel code, 286K rwdata, 1200K rodata, 168K init, 311K bss, 90276K re)
+	[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
+	[    0.000000] rcu: Hierarchical RCU implementation.
+	[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
+	[    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies.
+	[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
+	[    0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
+	[    0.000000] plic: mapped 2 interrupts with 1 handlers for 2 contexts.
+	[    0.000000] riscv_timer_init_dt: Registering clocksource cpuid [0] hartid [0]
+	[    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x1ec037a6a, max_idle_ns: 7052723236599 ns
+	[    0.000138] sched_clock: 64 bits at 520kHz, resolution 1919ns, wraps every 4398046510738ns
+	[    0.009429] printk: console [hvc0] enabled
+	[    0.009429] printk: console [hvc0] enabled
+	[    0.017850] printk: bootconsole [sbi0] disabled
+	[    0.017850] printk: bootconsole [sbi0] disabled
+	[    0.028029] Calibrating delay loop (skipped), value calculated using timer frequency.. 1.04 BogoMIPS (lpj=5208)
+	[    0.038753] pid_max: default: 32768 minimum: 301
+	[    0.050248] Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
+	[    0.058661] Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
+	[    0.069359] *** VALIDATE tmpfs ***
+	[    0.089093] *** VALIDATE proc ***
+	[    0.101135] *** VALIDATE cgroup ***
+	[    0.105019] *** VALIDATE cgroup2 ***
+	[    0.144310] rcu: Hierarchical SRCU implementation.
+	[    0.162836] smp: Bringing up secondary CPUs ...
+	[    0.167736] smp: Brought up 1 node, 1 CPU
+	[    0.185982] devtmpfs: initialized
+	[    0.216237] random: get_random_u32 called from bucket_table_alloc.isra.25+0x4e/0x15c with crng_init=0
+	[    0.236026] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
+	[    0.246916] futex hash table entries: 256 (order: 2, 16384 bytes, linear)
+	[    0.266994] NET: Registered protocol family 16
+	[    0.763362] clocksource: Switched to clocksource riscv_clocksource
+	[    0.770122] *** VALIDATE bpf ***
+	[    0.782837] *** VALIDATE ramfs ***
+	[    0.829997] NET: Registered protocol family 2
+	[    0.853577] tcp_listen_portaddr_hash hash table entries: 512 (order: 1, 8192 bytes, linear)
+	[    0.864085] TCP established hash table entries: 8192 (order: 4, 65536 bytes, linear)
+	[    0.875373] TCP bind hash table entries: 8192 (order: 5, 131072 bytes, linear)
+	[    0.887958] TCP: Hash tables configured (established 8192 bind 8192)
+	[    0.902149] UDP hash table entries: 512 (order: 2, 16384 bytes, linear)
+	[    0.909904] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes, linear)
+	[    0.924809] NET: Registered protocol family 1
+	[    0.948605] RPC: Registered named UNIX socket transport module.
+	[    0.956003] RPC: Registered udp transport module.
+	[    0.961565] RPC: Registered tcp transport module.
+	[    0.966432] RPC: Registered tcp NFSv4.1 backchannel transport module.
+	[    0.987180] Initialise system trusted keyrings
+	[    0.998953] workingset: timestamp_bits=46 max_order=18 bucket_order=0
+	[    1.323977] *** VALIDATE nfs ***
+	[    1.328520] *** VALIDATE nfs4 ***
+	[    1.334422] NFS: Registering the id_resolver key type
+	[    1.340148] Key type id_resolver registered
+	[    1.345280] Key type id_legacy registered
+	[    1.349820] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
+	[    1.357610] Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
+	[    1.866909] Key type asymmetric registered
+	[    1.872460] Asymmetric key parser 'x509' registered
+	[    1.878750] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
+	[    1.887480] io scheduler mq-deadline registered
+	[    1.892864] io scheduler kyber registered
+	[    3.905595] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
+	[    3.954332] fff0c2c000.uart: ttyS0 at MMIO 0xfff0c2c000 (irq = 1, base_baud = 4166687) is a 16550
+	[    4.254794] loop: module loaded
+	[    4.258269] piton_sd:v1.0 Apr 26, 2019
+	[    4.258269]
+	[    4.265170] gpt partition table header:
+	[    4.265283] signature: 5452415020494645
+	[    4.269258] revision: 10000
+	[    4.273746] size: 5c
+	[    4.276659] crc_header: 26b42404
+	[    4.278911] reserved: 0
+	[    4.282730] current lba: 1
+	[    4.285311] backup lda: 3b723ff
+	[    4.288093] partition entries lba: 2
+	[    4.291835] number partition entries: 80
+	[    4.295529] size partition entries: 80
+	[    9.473253]  piton_sd: piton_sd1
+	[   10.099676] libphy: Fixed MDIO Bus: probed
+	[   10.148782] NET: Registered protocol family 10
+	[   10.183418] Segment Routing with IPv6
+	[   10.189384] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
+	[   10.214449] NET: Registered protocol family 17
+	[   10.227413] Key type dns_resolver registered
+	[   10.240561] Loading compiled-in X.509 certificates
+	[   10.465264] EXT4-fs (piton_sd1): mounted filesystem with ordered data mode. Opts: (null)
+	[   10.475922] VFS: Mounted root (ext4 filesystem) readonly on device 254:1.
+	[   10.551865] devtmpfs: mounted
+	[   10.562744] Freeing unused kernel memory: 168K
+	[   10.567450] This architecture does not have kernel memory protection.
+	[   10.574688] Run /sbin/init as init process
+	[   10.578916]   with arguments:
+	[   10.582489]     /sbin/init
+	[   10.585312]   with environment:
+	[   10.588518]     HOME=/
+	[   10.591459]     TERM=linux
+	[   18.154373] systemd[1]: System time before build time, advancing clock.
+	[   18.565415] systemd[1]: systemd 238 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIB)
+	[   18.596359] systemd[1]: Detected architecture riscv64.
+
+	Welcome to Debian GNU/Linux buster/sid!
+
+	[   18.797150] systemd[1]: Set hostname to <openpiton>.
+	[   31.609244] random: systemd: uninitialized urandom read (16 bytes read)
+	[   31.630366] systemd[1]: Listening on /dev/initctl Compatibility Named Pipe.
+	[  OK  ] Listening on /dev/initctl Compatibility Named Pipe.
+	[   31.674820] random: systemd: uninitialized urandom read (16 bytes read)
+	[   31.806800] systemd[1]: Created slice system-serial\x2dgetty.slice.
+	[  OK  ] Created slice system-serial\x2dgetty.slice.
+	[   31.839855] random: systemd: uninitialized urandom read (16 bytes read)
+	[   31.850670] systemd[1]: Reached target Slices.
+	[  OK  ] Reached target Slices.
+	[   32.128005] systemd[1]: Reached target Swap.
+	[  OK  ] Reached target Swap.
+	[   32.180337] systemd[1]: Listening on Journal Socket.
+	[  OK  ] Listening on Journal Socket.
+	[   32.416448] systemd[1]: Mounting Kernel Debug File System...
+	Mounting Kernel Debug File System...
+	[   32.937934] systemd[1]: Starting Remount Root and Kernel File Systems...
+	Starting Remount Root and Kernel File Systems...
+	[   33.117472] urandom_read: 4 callbacks suppressed
+	[   33.117645] random: systemd: uninitialized urandom read (16 bytes read)
+	[   33.214868] systemd[1]: Started Forward Password Requests to Wall Directory Watch.
+	[  OK  ] Started Forward Password Requests to Wall Directory Watch.
+	[   33.366745] random: systemd: uninitialized urandom read (16 bytes read)
+	[   33.453262] systemd[1]: Listening on Journal Socket (/dev/log).
+	[  OK  ] Listening on Journal Socket (/dev/log).
+	[   33.627020] random: systemd: uninitialized urandom read (16 bytes read)
+	[   34.029973] systemd[1]: Starting Load Kernel Modules...
+	Starting Load Kernel Modules...
+	[  OK  ] Created slice system-getty.slice.
+	[  OK  ] Started Dispatch Password Requests to Console Directory Watch.
+	[  OK  ] Reached target Local Encrypted Volumes.
+	[  OK  ] Reached target Paths.
+	[  OK  ] Reached target Remote File Systems.
+	[  OK  ] Listening on udev Kernel Socket.
+	[  OK  ] Listening on udev Control Socket.
+	[  OK  ] Reached target Sockets.
+	Starting udev Coldplug all Devices...
+	Starting Journal Service...
+	[   37.108761] systemd[1]: Starting Create Static Device Nodes in /dev...
+	Starting Create Static Device Nodes in /dev...
+	[   37.941929] systemd[1]: Mounted Kernel Debug File System.
+	[  OK  ] Mounted Kernel Debug File System.
+	[   38.463855] systemd[1]: Started Remount Root and Kernel File Systems.
+	[  OK  ] Started Remount Root and Kernel File Systems.
+	[   39.614728] systemd[1]: Started Load Kernel Modules.
+	[  OK  ] Started Load Kernel Modules.
+	[   40.794332] systemd[1]: Starting Apply Kernel Variables...
+	Starting Apply Kernel Variables...
+	[   41.928338] systemd[1]: Starting Load/Save Random Seed...
+	Starting Load/Save Random Seed...
+	[   43.494757] systemd[1]: Started Create Static Device Nodes in /dev.
+	[  OK  ] Started Create Static Device Nodes in /dev.
+	[   44.795372] systemd[1]: Starting udev Kernel Device Manager...
+	Starting udev Kernel Device Manager...
+	[   45.043065] systemd[1]: Reached target Local File Systems (Pre).
+	[  OK  ] Reached target Local File Systems (Pre).
+	[   45.224716] systemd[1]: Reached target Local File Systems.
+	[  OK  ] Reached target Local File Systems.
+	[   46.036491] systemd[1]: Started Apply Kernel Variables.
+	[  OK  ] Started Apply Kernel Variables.
+	[   46.947879] systemd[1]: Started Load/Save Random Seed.
+	[  OK  ] Started Load/Save Random Seed.
+	[   47.910242] systemd[1]: Starting Raise network interfaces...
+	Starting Raise network interfaces...
+	[   48.119915] systemd[1]: Started Journal Service.
+	[  OK  ] Started Journal Service.
+	Starting Flush Journal to Persistent Storage...
+	[  OK  ] Started udev Kernel Device Manager.
+	[   55.369915] systemd-journald[88]: Received request to flush runtime journal from PID 1
+	[  OK  ] Started Flush Journal to Persistent Storage.
+	Starting Create Volatile Files and Directories...
+	[  OK  ] Started Raise network interfaces.
+	[  OK  ] Reached target Network.
+	[FAILED] Failed to start Create Volatile Files and Directories.
+	See 'systemctl status systemd-tmpfiles-setup.service' for details.
+	Starting Update UTMP about System Boot/Shutdown...
+	[FAILED] Failed to start Network Time Synchronization.
+	See 'systemctl status systemd-timesyncd.service' for details.
+	[  OK  ] Reached target System Time Synchronized.
+	[  OK  ] Stopped Network Time Synchronization.
+	[  OK  ] Started udev Coldplug all Devices.
+	[  OK  ] Found device /dev/hvc0.
+	[  OK  ] Reached target System Initialization.
+	[  OK  ] Reached target Basic System.
+	[  OK  ] Started Regular background program processing daemon.
+	[  OK  ] Started Daily Cleanup of Temporary Directories.
+	Starting Permit User Sessions...
+	[  OK  ] Started Daily apt download activities.
+	[  OK  ] Started Daily apt upgrade and clean activities.
+	[  OK  ] Reached target Timers.
+	[  OK  ] Started Permit User Sessions.
+	[  OK  ] Started Serial Getty on hvc0.
+	[  OK  ] Reached target Login Prompts.
+	[  OK  ] Reached target Multi-User System.
+	[  OK  ] Reached target Graphical Interface.
+
+	Debian GNU/Linux buster/sid openpiton hvc0
+
+	openpiton login: