qemu-e2k

History

Blue Swirl a8a826a3c3 exec: refactor cpu_restore_state Refactor common code around calls to cpu_restore_state(). tb_find_pc() has now no external users, make it static. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>		2012-12-16 08:35:24 +00:00
..
cpu-qom.h
cpu.c
cpu.h	cpus: Pass CPUState to [qemu_]cpu_has_work()	2012-10-31 04:11:37 +01:00
helper.c
helper.h
machine.c
Makefile.objs
op_helper.c	exec: refactor cpu_restore_state	2012-12-16 08:35:24 +00:00
README
TODO
translate.c	TCG: Use gen_opc_instr_start from context instead of global variable.	2012-12-08 14:24:43 +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.


Programmatically terminate the emulator
----------------------------------------
Originally neither the LatticeMico32 nor its peripherals support a
mechanism to shut down the machine. Emulation aware programs can write to a
to a special register within the system control block to shut down the
virtual machine.  For more details see hw/lm32_sys.c. The lm32-evr is the
first BSP which instantiate this model. A (32 bit) write to 0xfff0000
causes a vm shutdown.


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);