v2.2.8

- fix issue #4: incorrect irq routing of plic sources > 31
- hexfive-conf@95470e
- hexfive-kern@7fcd98
- minor non-functional changes to zones
- update README.md url links to 2.2.8

v2.2.7

- renew X.509 certs (exp 2024-12-31)
- update ext/mbedtls to 2.28.6
- update ext/libmbedtls.a (2.28.6)
- update README.md links to 2.2.7

Update README.md

Update README.md

v2.2.4

- Upgrade lwip to STABLE-2_1_3_RELEASE (+ mqtt.c @089697b)
- Upgrade mbedtls to v2.28.1
- zone3.1 poll inbox when resuming from wfi with global irq disabled
- Update README.md

Enable X300 R0W1 policy (hexfive-conf @5e5efc)

 Many bug fixes and improvements (v2.2.1)

- add asynchronous message delivery
- add submodule ext/printf v4.0.0
- add FreeRTOS deep sleep
- add atomic mem access to peripherals
- move kernel runtime to ITIM to free 4KB RAM
- zone1: link with printf.c to reduce code size to < 128K
- zone2: link with printf.c and strtok.c to reduce code size < 16K
- fix -Wall and -Wextra warnings
- update riscv-gnu-toolchain-20210618 (rv32i|rv32e|rv64i)mac
- update riscv-openocd-20210807
- update manual.pdf and README.md

multizone.jar @1b9f31 (v2.2.1) / kernel @6b58e8 (v2.2.1):

- major redesign of kernel internal data structures
- up to 32/64 clint + 64/128 plic sources
- up to 256 clic sources for both rv32 and rv64
- reduce size of most kern vars from REGSIZE to 4-byte
- increase trap & emulation i-cache size
- add support for SiFive clic (E21)
- reintroduce support for rv32e 16-regs
- update riscv-gnu-toolchain-20210618 (rv32i|rv32e|rv64i)c

Update hexfive-kern @85cca8, add HW boot code