Release notes

Rocket-core (Chisel)
- Add tag cache and improved security features.
Software environment
- Most of the previous bare-metal program functionality integrated into one 64K executable
- Implement 4-bit read/write SD-mode access to memory cards in Linux.
- Console output appears on serial port and VGA screen in parallel.
- Bare metal booting kernel in 4-bit SD-mode supported.
lowRISC-chip
- Add Minion core (Pulpino based) to control SD-card, keyboard, and VGA display.
- Standalone operation (without personal computer) possible.
- VGA-compatible text display.
- USB-keyboard (PS/2 compatible)
Design environment
- Updated demo images for NEXYS4-DDR FPGA.
- Add cfgmem and program-cfgmem targets to fpga Makefile.
Missing from this release vs the previous
- Bitstream configuration from SD-card is no longer convenient.
- Quad SPI memory execute-in-place is missing from initial demo images.