FU540-C000 RISC-V SoC
=====================
The FU540-C000 is the world’s first 4+1 64-bit RISC‑V SoC from SiFive.

The HiFive Unleashed development platform is based on FU540-C000 and capable
of running Linux.

Mainline support
================
The support for following drivers are already enabled:
1. SiFive UART Driver.
2. SiFive PRCI Driver for clock.
3. Cadence MACB ethernet driver for networking support.

TODO:
1. SPI host driver is still missing.
2. SPI MMC driver does not compile and needs a re-write using U-Boot DM.
2. U-Boot expects the serial console device entry to be present under /chosen
   DT node. Example:
   chosen {
        stdout-path = "/soc/serial@10010000:115200";
   };

   Without a serial console U-Boot will panic.

Building
========
1. Add the RISC-V toolchain to your PATH.
2. Setup ARCH & cross compilation enviornment variable.
   a. export ARCH=riscv
   b. export CROSS_COMPILE=<riscv64 toolchain prefix>
3. make sifive_fu540_defconfig
4. make

Flashing
========
The current U-Boot port is supported in S-mode only and loaded directly
into DRAM.

A prior stage (M-mode) firmware/bootloader (e.g OpenSBI) is required to
boot the u-boot.bin in S-mode and provide M-mode runtime services.

Currently, the u-boot.bin is used as a payload of the OpenSBI FW_PAYLOAD
firmware. We need to compile OpenSBI with below command:
make PLATFORM=sifive/fu540 FW_PAYLOAD_PATH=<path to u-boot.bin> FW_PAYLOAD_FDT_PATH=<path to hifive-unleashed-a00.dtb from Linux>
(Note: Prefer hifive-unleashed-a00.dtb from Linux-5.3 or higher)
(Note: Linux-5.2 is also fine but it does not have ethernet DT node)

More detailed description of steps required to build FW_PAYLOAD firmware
is beyond the scope of this document. Please refer OpenSBI documenation.
(Note: OpenSBI git repo is at https://github.com/riscv/opensbi.git)

Once the prior stage firmware/bootloader binary is generated, it should be
copied to the first partition of the sdcard.

sudo dd if=<prior_stage_firmware_binary> of=/dev/disk2s1 bs=1024

Booting
=======
Once you plugin the sdcard and power up, you should see the U-Boot prompt.

Sample boot log from HiFive Unleashed board
===========================================
U-Boot 2019.07-rc4-00013-g1837f893b0 (Jun 20 2019 - 11:08:48 +0530)

CPU:   rv64imafdc
Model: SiFive HiFive Unleashed A00
DRAM:  8 GiB
In:    serial@10010000
Out:   serial@10010000
Err:   serial@10010000
Net:   eth0: ethernet@10090000
Hit any key to stop autoboot:  0
=> version
U-Boot 2019.07-rc4-00013-g1837f893b0 (Jun 20 2019 - 11:08:48 +0530)

riscv64-linux-gcc.br_real (Buildroot 2018.11-rc2-00003-ga0787e9) 8.2.0
GNU ld (GNU Binutils) 2.31.1
=>
===============================================================================

Now you can configure your networking, tftp server and use tftp boot method to
load uImage.

==========================================================================
=> setenv ipaddr 10.206.5.241
=> setenv netmask 255.255.252.0
=> setenv serverip 10.206.4.143
=> setenv gateway 10.206.4.1
=> tftpboot ${kernel_addr_r} /sifive/fu540/uImage
ethernet@10090000: PHY present at 0
ethernet@10090000: Starting autonegotiation...
ethernet@10090000: Autonegotiation complete
ethernet@10090000: link up, 1000Mbps full-duplex (lpa: 0x7c00)
Using ethernet@10090000 device
TFTP from server 10.206.4.143; our IP address is 10.206.5.241
Filename '/sifive/fu540/uImage'.
Load address: 0x80600000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ########################################
         1.5 MiB/s
done
Bytes transferred = 9162364 (8bce7c hex)
=> tftpboot ${ramdisk_addr_r} /sifive/fu540/uRamdisk
ethernet@10090000: PHY present at 0
ethernet@10090000: Starting autonegotiation...
ethernet@10090000: Autonegotiation complete
ethernet@10090000: link up, 1000Mbps full-duplex (lpa: 0x7c00)
Using ethernet@10090000 device
TFTP from server 10.206.4.143; our IP address is 10.206.5.241
Filename '/sifive/fu540/uRamdisk'.
Load address: 0x82500000
Loading: #################################################################
         #################################################################
         ##################################
         448.2 KiB/s
done
Bytes transferred = 2398272 (249840 hex)
=> setenv bootargs "root=/dev/ram rw console=ttySIF0 earlycon=sbi"
=> bootm ${kernel_addr_r} ${ramdisk_addr_r} ${fdtcontroladdr}
## Booting kernel from Legacy Image at 80600000 ...
   Image Name:   Linux
   Image Type:   RISC-V Linux Kernel Image (uncompressed)
   Data Size:    9162300 Bytes = 8.7 MiB
   Load Address: 80200000
   Entry Point:  80200000
   Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 82500000 ...
   Image Name:   Linux RootFS
   Image Type:   RISC-V Linux RAMDisk Image (uncompressed)
   Data Size:    2398208 Bytes = 2.3 MiB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
## Flattened Device Tree blob at ff795730
   Booting using the fdt blob at 0xff795730
   Loading Kernel Image ... OK
   Using Device Tree in place at 00000000ff795730, end 00000000ff799dac

Starting kernel ...

[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Linux version 5.2.0-rc1-00003-gb9543e66e700 (anup@anup-lab-machine) (gcc version 8.2.0 (Buildroot 2018.11-rc2-00003-ga0787e9)) #1 SMP Thu Jun 20 11:41:26 IST 2019
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] Initial ramdisk at: 0x(____ptrval____) (2398208 bytes)
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000ffffffff]
[    0.000000]   Normal   [mem 0x0000000100000000-0x000000027fffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x000000027fffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x000000027fffffff]
[    0.000000] software IO TLB: mapped [mem 0xfb795000-0xff795000] (64MB)
[    0.000000] CPU with hartid=0 is not available
[    0.000000] CPU with hartid=0 is not available
[    0.000000] elf_hwcap is 0x112d
[    0.000000] percpu: Embedded 17 pages/cpu s29592 r8192 d31848 u69632
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 2067975
[    0.000000] Kernel command line: root=/dev/ram rw console=ttySIF0 earlycon=sbi
[    0.000000] Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes)
[    0.000000] Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes)
[    0.000000] Sorting __ex_table...
[    0.000000] Memory: 8182056K/8386560K available (5753K kernel code, 357K rwdata, 1804K rodata, 204K init, 808K bss, 204504K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
[    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
[    0.000000] NR_IRQS: 0, nr_irqs: 0, preallocated irqs: 0
[    0.000000] plic: mapped 53 interrupts with 4 handlers for 9 contexts.
[    0.000000] riscv_timer_init_dt: Registering clocksource cpuid [0] hartid [2]
[    0.000000] clocksource: riscv_clocksource: mask: 0xffffffffffffffff max_cycles: 0x1d854df40, max_idle_ns: 3526361616960 ns
[    0.000007] sched_clock: 64 bits at 1000kHz, resolution 1000ns, wraps every 2199023255500ns
[    0.008553] Console: colour dummy device 80x25
[    0.012990] Calibrating delay loop (skipped), value calculated using timer frequency.. 2.00 BogoMIPS (lpj=4000)
[    0.023103] pid_max: default: 32768 minimum: 301
[    0.028269] Mount-cache hash table entries: 16384 (order: 5, 131072 bytes)
[    0.035068] Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes)
[    0.042770] *** VALIDATE proc ***
[    0.045610] *** VALIDATE cgroup1 ***
[    0.049157] *** VALIDATE cgroup2 ***
[    0.053743] rcu: Hierarchical SRCU implementation.
[    0.058297] smp: Bringing up secondary CPUs ...
[    0.064134] smp: Brought up 1 node, 4 CPUs
[    0.069114] devtmpfs: initialized
[    0.073281] random: get_random_u32 called from bucket_table_alloc.isra.10+0x4e/0x160 with crng_init=0
[    0.082157] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[    0.091634] futex hash table entries: 1024 (order: 4, 65536 bytes)
[    0.098480] NET: Registered protocol family 16
[    0.114101] vgaarb: loaded
[    0.116397] SCSI subsystem initialized
[    0.120358] usbcore: registered new interface driver usbfs
[    0.125541] usbcore: registered new interface driver hub
[    0.130936] usbcore: registered new device driver usb
[    0.136618] clocksource: Switched to clocksource riscv_clocksource
[    0.148108] NET: Registered protocol family 2
[    0.152358] tcp_listen_portaddr_hash hash table entries: 4096 (order: 4, 65536 bytes)
[    0.159928] TCP established hash table entries: 65536 (order: 7, 524288 bytes)
[    0.169027] TCP bind hash table entries: 65536 (order: 8, 1048576 bytes)
[    0.178360] TCP: Hash tables configured (established 65536 bind 65536)
[    0.184653] UDP hash table entries: 4096 (order: 5, 131072 bytes)
[    0.190819] UDP-Lite hash table entries: 4096 (order: 5, 131072 bytes)
[    0.197618] NET: Registered protocol family 1
[    0.201892] RPC: Registered named UNIX socket transport module.
[    0.207395] RPC: Registered udp transport module.
[    0.212159] RPC: Registered tcp transport module.
[    0.216940] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    0.223445] PCI: CLS 0 bytes, default 64
[    0.227726] Unpacking initramfs...
[    0.260556] Freeing initrd memory: 2336K
[    0.264652] workingset: timestamp_bits=62 max_order=21 bucket_order=0
[    0.278452] NFS: Registering the id_resolver key type
[    0.282841] Key type id_resolver registered
[    0.287067] Key type id_legacy registered
[    0.291155] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    0.298299] NET: Registered protocol family 38
[    0.302470] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
[    0.309906] io scheduler mq-deadline registered
[    0.314501] io scheduler kyber registered
[    0.354134] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[    0.360725] 10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 4, base_baud = 0) is a SiFive UART v0
[    0.369191] printk: console [ttySIF0] enabled
[    0.369191] printk: console [ttySIF0] enabled
[    0.377938] printk: bootconsole [sbi0] disabled
[    0.377938] printk: bootconsole [sbi0] disabled
[    0.387298] 10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 1, base_baud = 0) is a SiFive UART v0
[    0.396411] [drm] radeon kernel modesetting enabled.
[    0.409818] loop: module loaded
[    0.412606] libphy: Fixed MDIO Bus: probed
[    0.416870] macb 10090000.ethernet: Registered clk switch 'sifive-gemgxl-mgmt'
[    0.423570] macb: GEM doesn't support hardware ptp.
[    0.428469] libphy: MACB_mii_bus: probed
[    1.053009] Microsemi VSC8541 SyncE 10090000.ethernet-ffffffff:00: attached PHY driver [Microsemi VSC8541 SyncE] (mii_bus:phy_addr=10090000.ethernet-ffffffff:00, irq=POLL)
[    1.067548] macb 10090000.ethernet eth0: Cadence GEM rev 0x10070109 at 0x10090000 irq 7 (70:b3:d5:92:f2:f3)
[    1.077330] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k
[    1.083069] e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
[    1.089061] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    1.095485] ehci-pci: EHCI PCI platform driver
[    1.099947] ehci-platform: EHCI generic platform driver
[    1.105196] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[    1.111286] ohci-pci: OHCI PCI platform driver
[    1.115742] ohci-platform: OHCI generic platform driver
[    1.121142] usbcore: registered new interface driver uas
[    1.126269] usbcore: registered new interface driver usb-storage
[    1.132331] mousedev: PS/2 mouse device common for all mice
[    1.137978] usbcore: registered new interface driver usbhid
[    1.143325] usbhid: USB HID core driver
[    1.148022] NET: Registered protocol family 10
[    1.152609] Segment Routing with IPv6
[    1.155571] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[    1.161927] NET: Registered protocol family 17
[    1.165907] Key type dns_resolver registered
[    1.171694] Freeing unused kernel memory: 204K
[    1.175375] This architecture does not have kernel memory protection.
[    1.181792] Run /init as init process
           _  _
          | ||_|
          | | _ ____  _   _  _  _
          | || |  _ \| | | |\ \/ /
          | || | | | | |_| |/    \
          |_||_|_| |_|\____|\_/\_/

               Busybox Rootfs

Please press Enter to activate this console.
/ #