[PATCH 7/9] RISC-V: add initial LiteX SoC support

[Antony Pavlov]

On Wed, 05 May 2021 12:45:23 +0200
Jan Lübbe <jlu at pengutronix.de> wrote:

> On Wed, 2021-05-05 at 13:08 +0300, Antony Pavlov wrote:
> > LiteX is a Migen-based System on Chip, supporting softcore
> > VexRiscv CPU, a 32-bits Linux Capable RISC-V CPU.
> > 
> > See https://github.com/enjoy-digital/litex and
> > https://github.com/litex-hub/linux-on-litex-vexriscv
> > for details.
> > 
> > Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
> > ---
> > 
> > 
> 
> 
> > +config MACH_LITEX
> > +	bool "litex family"
> > +	select ARCH_RV32I
> > +	select HAS_DEBUG_LL
> > +	select HAS_NMON
> > +	select USE_COMPRESSED_DTB
> > +	select RISCV_SBI
> > +
> 
> 
> Hmm, there is also https://github.com/litex-hub/linux-on-litex-rocket/ which
> uses the 64-bit RocketChip CPU. How would that fit into this naming scheme?
> Would it be a different MACH?

Rocket is a 64-bit core, VexRiscv is a 32-bit core.
All LiteX family SoC use the same peripheral IP cores, but different CPU cores.

The situation is similar to MIPS Malta FPGA devboard, main FPGA can be burned with
very different CPU bitstreams:

config MIPS_MALTA
        bool "MIPS Malta board"
        ...
        select SYS_HAS_CPU_MIPS32_R1
        select SYS_HAS_CPU_MIPS32_R2
        select SYS_HAS_CPU_MIPS32_R3_5
        select SYS_HAS_CPU_MIPS32_R5
        select SYS_HAS_CPU_MIPS32_R6
        select SYS_HAS_CPU_MIPS64_R1
        select SYS_HAS_CPU_MIPS64_R2
        select SYS_HAS_CPU_MIPS64_R6
        select SYS_HAS_CPU_NEVADA
        select SYS_HAS_CPU_RM7000


I'll investigate the problem more carefully.
Thanks for noting!

-- 
Best regards,
  Antony Pavlov