I am new to RISC-V, Rocket-Chip, and Chisel, and have been searching around for tutorials, and documents, to help me learn to write Chisel code. It seems to be spread out and new bits and pieces trickle in. I will answer this question with my list, what have you found?
A Chisel 2 documentation page, including tutorial, manual, and cheat-sheet: https://chisel.eecs.berkeley.edu/documentation.html
Chisel 3 wiki: https://github.com/ucb-bar/chisel3/wiki
Style guide, which helps those new, like me, understand nuances and figure out how to do non-obvious things: https://github.com/ccelio/chisel-style-guide
This page has a list of repositories, including chisel example code, a skeleton for new projects, tutorials, documentation (see below): https://github.com/ucb-bar
The Chisel user group: https://groups.google.com/forum/#!forum/chisel-users
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Some items extracted from the above ucb-bar page:
A skeleton for "clean" new Chisel projects: https://github.com/ucb-bar/pwm-chisel-example
Teaching processors (Simple RISC-V processors, as examples to learn Chisel): https://github.com/ucb-bar/riscv-sodor
wiki for teaching processors: https://github.com/ucb-bar/riscv-sodor/wiki
Test harnesses for testing Chisel modules -- [edit] warning: early version for Chisel3, which seems limited to non-interactive tests: https://github.com/ucb-bar/chisel-testers
Chisel tutorial: https://github.com/ucb-bar/chisel-tutorial
Chisel-doc repository, with its own makefile, that builds documentation: https://github.com/ucb-bar/chisel-doc