The patch series is based on another one [Basic early_printk and smoke
test implementation] which hasn't been commited yet.

The patch series provides a basic implementation of exception handling.
It can do only basic things such as decode a cause of an exception,
save/restore registers and execute "wfi" instruction if an exception
can not be handled.

To verify that exception handling works well it was implemented macros
from <asm/bug.h> such as BUG/WARN/run_in_exception/assert_failed.
The implementation of macros is used "ebreak" instruction and set up bug
frame tables for each type of macros.
Also it was implemented register save/restore to return and continue work
after WARN/run_in_exception.
Not all functionality of the macros was implemented as some of them
require hard-panic the system which is not available now. Instead of
hard-panic 'wfi' instruction is used but it should be definitely changed
in the neareset future.
It wasn't implemented show_execution_state() and stack trace discovering
as it's not necessary now.

Oleksii Kurochko (14):
  xen/riscv: add _zicsr to CFLAGS
  xen/riscv: add <asm/asm.h> header
  xen/riscv: add <asm/riscv_encoding.h header
  xen/riscv: add <asm/csr.h> header
  xen/riscv: add early_printk_hnum() function
  xen/riscv: introduce exception context
  xen/riscv: introduce exception handlers implementation
  xen/riscv: introduce decode_cause() stuff
  xen/riscv: introduce do_unexpected_trap()
  xen/riscv: mask all interrupts
  xen/riscv: introduce setup_trap_handler()
  xen/riscv: introduce an implementation of macros from <asm/bug.h>
  xen/riscv: test basic handling stuff
  automation: add smoke test to verify macros from bug.h

 automation/scripts/qemu-smoke-riscv64.sh    |   2 +
 xen/arch/riscv/Makefile                     |   2 +
 xen/arch/riscv/arch.mk                      |   2 +-
 xen/arch/riscv/early_printk.c               |  39 +
 xen/arch/riscv/entry.S                      |  97 ++
 xen/arch/riscv/include/asm/asm.h            |  54 ++
 xen/arch/riscv/include/asm/bug.h            | 120 +++
 xen/arch/riscv/include/asm/csr.h            |  82 ++
 xen/arch/riscv/include/asm/early_printk.h   |   2 +
 xen/arch/riscv/include/asm/processor.h      | 114 +++
 xen/arch/riscv/include/asm/riscv_encoding.h | 945 ++++++++++++++++++++
 xen/arch/riscv/include/asm/traps.h          |  13 +
 xen/arch/riscv/riscv64/head.S               |   5 +
 xen/arch/riscv/setup.c                      |  27 +
 xen/arch/riscv/traps.c                      | 229 +++++
 xen/arch/riscv/xen.lds.S                    |  10 +
 16 files changed, 1742 insertions(+), 1 deletion(-)
 create mode 100644 xen/arch/riscv/entry.S
 create mode 100644 xen/arch/riscv/include/asm/asm.h
 create mode 100644 xen/arch/riscv/include/asm/bug.h
 create mode 100644 xen/arch/riscv/include/asm/csr.h
 create mode 100644 xen/arch/riscv/include/asm/processor.h
 create mode 100644 xen/arch/riscv/include/asm/riscv_encoding.h
 create mode 100644 xen/arch/riscv/include/asm/traps.h
 create mode 100644 xen/arch/riscv/traps.c

-- 
2.39.0