Getting started with risc-v

For quite some time around was looking around to start on understanding on RISCV architecture and implementation details.

Lots of unknowns to get started with:

• What is RISCV?
• Where it is originated from?
• Where is the actual specification?
• How open source is it?

Before starting on RISCV, What is ISA? An ISA specifies the Instruction Set Architecture. On an above earth level understanding. it provides the instructions available, its formats and standard notion of user level details. Some of the details are like the list of instructions available, registers available, stack, how to handle functions…