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Lluís Vilanova 1bcea73e13 tcg: Add type for vCPU pointers 
Adds the 'TCGv_env' type for pointers to 'CPUArchState' objects. The
tracing infrastructure later needs to differentiate between regular
pointers and pointers to vCPUs.

Also changes all targets to use the new 'TCGv_env' type instead of the
generic 'TCGv_ptr'. As of now, the change is merely cosmetic ('TCGv_env'
translates into 'TCGv_ptr'), but that could change in the future to
enforce the difference.

Note that a 'TCGv_env' type (for 'CPUState') is not added, since all
helpers currently receive the architecture-specific
pointer ('CPUArchState').

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Acked-by: Richard Henderson <rth@twiddle.net>
Message-id: 145641859552.30295.7821536833590725201.stgit@localhost
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 		2016-03-01 13:27:09 +00:00
..
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: Use cpu_exec_interrupt qom hook 2014-09-25 18:54:22 +01:00
cpu.c lm32: Clean up includes 2016-01-29 15:07:22 +00:00
cpu.h all: Clean up includes 2016-02-23 12:43:05 +00:00
gdbstub.c lm32: Clean up includes 2016-01-29 15:07:22 +00:00
helper.c log: do not unnecessarily include qom/cpu.h 2016-02-03 09:19:10 +00:00
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 lm32: Clean up includes 2016-01-29 15:07:22 +00:00
op_helper.c lm32: Clean up includes 2016-01-29 15:07:22 +00:00
translate.c tcg: Add type for vCPU pointers 2016-03-01 13:27:09 +00:00

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);