qemu/target-lm32
Markus Armbruster 07f5a25875 target-*: Clean up cpu.h header guards
Most of them use guard symbols like CPU_$target_H, but we also have
__MIPS_CPU_H__ and __TRICORE_CPU_H__.  They all upset
scripts/clean-header-guards.pl.

The script dislikes CPU_$target_H because they don't match their file
name (they should, to make guard collisions less likely).  The others
are reserved identifiers.

Clean them all up: use guard symbol $target_CPU_H for
target-$target/cpu.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
..
Makefile.objs target-lm32: add semihosting support 2014-05-24 19:42:29 +02:00
README lm32: remove lm32_sys 2014-05-24 19:43:52 +02:00
TODO target-lm32: add breakpoint/watchpoint support 2014-02-04 19:47:06 +01:00
cpu-qom.h target-lm32: make cpu-qom.h not target specific 2016-05-19 13:08:04 +02:00
cpu.c cpu: move exec-all.h inclusion out of cpu.h 2016-05-19 16:42:29 +02:00
cpu.h target-*: Clean up cpu.h header guards 2016-07-12 16:19:16 +02:00
gdbstub.c qemu-common: push cpu.h inclusion out of qemu-common.h 2016-05-19 16:42:29 +02:00
helper.c cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc() 2016-06-09 15:55:02 +01:00
helper.h tcg: Invert the inclusion of helper.h 2014-05-28 09:33:54 -07:00
lm32-semi.c lm32: Clean up includes 2016-01-29 15:07:22 +00:00
machine.c qemu-common: push cpu.h inclusion out of qemu-common.h 2016-05-19 16:42:29 +02:00
op_helper.c Fix confusing argument names in some common functions 2016-07-12 13:06:08 +01:00
translate.c exec: [tcg] Track which vCPU is performing translation and execution 2016-06-20 15:30:01 +01:00

README

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);