qemu/target/lm32
Markus Armbruster 54d31236b9 sysemu: Split sysemu/runstate.h off sysemu/sysemu.h
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related
to the system-emulator.  Evidence:

* It's included widely: in my "build everything" tree, changing
  sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600
  objects (not counting tests and objects that don't depend on
  qemu/osdep.h, down from 5400 due to the previous two commits).

* It pulls in more than a dozen additional headers.

Split stuff related to run state management into its own header
sysemu/runstate.h.

Touching sysemu/sysemu.h now recompiles some 850 objects.  qemu/uuid.h
also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400
to 4200.  Touching new sysemu/runstate.h recompiles some 500 objects.

Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also
add qemu/main-loop.h.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-30-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[Unbreak OS-X build]
2019-08-16 13:37:36 +02:00
..
cpu-param.h tcg: Split out target/arch/cpu-param.h 2019-06-10 07:03:34 -07:00
cpu-qom.h
cpu.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
cpu.h migration: Move the VMStateDescription typedef to typedefs.h 2019-08-16 13:31:52 +02:00
gdbstub.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
helper.c Clean up inclusion of sysemu/sysemu.h 2019-08-16 13:31:53 +02:00
helper.h
lm32-semi.c
machine.c Include hw/boards.h a bit less 2019-08-16 13:31:53 +02:00
Makefile.objs
op_helper.c sysemu: Split sysemu/runstate.h off sysemu/sysemu.h 2019-08-16 13:37:36 +02:00
README
TODO
translate.c target/lm32: Use env_cpu, env_archcpu 2019-06-10 07:03:42 -07:00

LatticeMico32 target
--------------------

General
-------
All opcodes including the JUART CSRs are supported.


JTAG UART
---------
JTAG UART is routed to a serial console device. For the current boards it
is the second one. Ie to enable it in the qemu virtual console window use
the following command line parameters:
  -serial vc -serial vc
This will make serial0 (the lm32_uart) and serial1 (the JTAG UART)
available as virtual consoles.


Semihosting
-----------
Semihosting on this target is supported. Some system calls like read, write
and exit are executed on the host if semihosting is enabled. See
target/lm32-semi.c for all supported system calls. Emulation aware programs
can use this mechanism to shut down the virtual machine and print to the
host console. See the tcg tests for an example.


Special instructions
--------------------
The translation recognizes one special instruction to halt the cpu:
  and r0, r0, r0
On real hardware this instruction is a nop. It is not used by GCC and
should (hopefully) not be used within hand-crafted assembly.
Insert this instruction in your idle loop to reduce the cpu load on the
host.


Ignoring the MSB of the address bus
-----------------------------------
Some SoC ignores the MSB on the address bus. Thus creating a shadow memory
area. As a general rule, 0x00000000-0x7fffffff is cached, whereas
0x80000000-0xffffffff is not cached and used to access IO devices. This
behaviour can be enabled with:
  cpu_lm32_set_phys_msb_ignore(env, 1);