The OpenISA RV32M1 SoC has four CPU cores. Two of these are RISC-V
32-bit cores, which are named "RI5CY" and "ZERO-RISCY". (The other two
cores are ARM Cortex-M0+ and -M4.) This patch adds basic SoC
enablement for the RISC-V cores:
- basic dtsi, to be extended as additional drivers are added
- SoC definition in soc/riscv32/openisa_rv32m1 for RI5CY / ZERO-RISCY
- system timer driver for RI5CY, based on LPTMR0 peripheral
The timer driver will be generalized a bit soon once proper
multi-level interrupt support is available.
Emphasis is on supporting the RI5CY core as the more capable of the
two; the ZERO-RISCY SoC definitions are a good starting point, but
additional work setting up a dtsi and initial drivers is needed to
support that core.
Signed-off-by: Marti Bolivar <marti@foundries.io>
Signed-off-by: Michael Scott <mike@foundries.io>