Update polarfire.md

[sand7000]

Added some (hopefully) helpful additional content about booting on QEMY emulated polarfire.

[Ivan-Velickovic]

I used the configuration described on the sel4test page: ../init-build.sh -DPLATFORM=polarfire -DSel4testAllowSettingsOverride=True -DElfloaderImage=binary -DKernelVerificationBuild=OFF, but when I run with QEMU I get the following:

qemu-system-riscv64 -M microchip-icicle-kit -smp 5 -m 2G -display none -serial stdio -serial null -serial null -kernel images/sel4test-driver-image-riscv-polarfire -dtb ../mpfs_icicle.dtb

OpenSBI v1.3.1
   ____                    _____ ____ _____
  / __ \                  / ____|  _ \_   _|
 | |  | |_ __   ___ _ __ | (___ | |_) || |
 | |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
 | |__| | |_) |  __/ | | |____) | |_) || |_
  \____/| .__/ \___|_| |_|_____/|___/_____|
        | |
        |_|

Platform Name             : SiFive,FU540G
Platform Features         : medeleg
Platform HART Count       : 5
Platform IPI Device       : aclint-mswi
Platform Timer Device     : aclint-mtimer @ 1000000Hz
Platform Console Device   : uart8250
Platform HSM Device       : ---
Platform PMU Device       : ---
Platform Reboot Device    : ---
Platform Shutdown Device  : ---
Platform Suspend Device   : ---
Platform CPPC Device      : ---
Firmware Base             : 0x80000000
Firmware Size             : 234 KB
Firmware RW Offset        : 0x20000
Firmware RW Size          : 106 KB
Firmware Heap Offset      : 0x30000
Firmware Heap Size        : 42 KB (total), 2 KB (reserved), 9 KB (used), 30 KB (free)
Firmware Scratch Size     : 4096 B (total), 760 B (used), 3336 B (free)
Runtime SBI Version       : 1.0

Domain0 Name              : root
Domain0 Boot HART         : 3
Domain0 HARTs             : 0*,1*,2*,3*,4*
Domain0 Region00          : 0x0000000002000000-0x000000000200ffff M: (I,R,W) S/U: ()
Domain0 Region01          : 0x0000000080000000-0x000000008001ffff M: (R,X) S/U: ()
Domain0 Region02          : 0x0000000080020000-0x000000008003ffff M: (R,W) S/U: ()
Domain0 Region03          : 0x0000000000000000-0xffffffffffffffff M: (R,W,X) S/U: (R,W,X)
Domain0 Next Address      : 0x0000000080200000
Domain0 Next Arg1         : 0x00000000bfe00000
Domain0 Next Mode         : S-mode
Domain0 SysReset          : yes
Domain0 SysSuspend        : yes

Boot HART ID              : 3
Boot HART Domain          : root
Boot HART Priv Version    : v1.10
Boot HART Base ISA        : rv64imafdc
Boot HART ISA Extensions  : none
Boot HART PMP Count       : 16
Boot HART PMP Granularity : 4
Boot HART PMP Address Bits: 54
Boot HART MHPM Count      : 0
Boot HART MIDELEG         : 0x0000000000000222
Boot HART MEDELEG         : 0x000000000000b109

Nothing seems to happen after OpenSBI starts. Not sure whether you ran into this.

[sand7000]

Hey Ivan,

This seems to be the same issue I asked you about here:

https://sel4.discourse.group/t/microchip-polarfire-icicle-kit-status/675/24

I thought we had this one licked based on your helpful instructions but I am hitting it again now. My best guess is that I was using a different version of seL4 when I built sel4test and it was working then. I will try to find some time tomorrow to play with it more maybe I can at least figure out the version that worked.