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We've currently got 18 architectures in QEMU, and thus 18 target-xxx folders in the root folder of the QEMU source tree. More architectures (e.g. RISC-V, AVR) are likely to be included soon, too, so the main folder of the QEMU sources slowly gets quite overcrowded with the target-xxx folders. To disburden the main folder a little bit, let's move the target-xxx folders into a dedicated target/ folder, so that target-xxx/ simply becomes target/xxx/ instead. Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part] Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part] Acked-by: Michael Walle <michael@walle.cc> [lm32 part] Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part] Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part] Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part] Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part] Acked-by: Richard Henderson <rth@twiddle.net> [alpha part] Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part] Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part] Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part] Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part] Signed-off-by: Thomas Huth <thuth@redhat.com>
46 lines
1.5 KiB
Plaintext
46 lines
1.5 KiB
Plaintext
LatticeMico32 target
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General
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-------
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All opcodes including the JUART CSRs are supported.
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JTAG UART
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---------
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JTAG UART is routed to a serial console device. For the current boards it
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is the second one. Ie to enable it in the qemu virtual console window use
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the following command line parameters:
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-serial vc -serial vc
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This will make serial0 (the lm32_uart) and serial1 (the JTAG UART)
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available as virtual consoles.
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Semihosting
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-----------
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Semihosting on this target is supported. Some system calls like read, write
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and exit are executed on the host if semihosting is enabled. See
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target/lm32-semi.c for all supported system calls. Emulation aware programs
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can use this mechanism to shut down the virtual machine and print to the
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host console. See the tcg tests for an example.
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Special instructions
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--------------------
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The translation recognizes one special instruction to halt the cpu:
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and r0, r0, r0
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On real hardware this instruction is a nop. It is not used by GCC and
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should (hopefully) not be used within hand-crafted assembly.
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Insert this instruction in your idle loop to reduce the cpu load on the
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host.
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Ignoring the MSB of the address bus
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-----------------------------------
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Some SoC ignores the MSB on the address bus. Thus creating a shadow memory
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area. As a general rule, 0x00000000-0x7fffffff is cached, whereas
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0x80000000-0xffffffff is not cached and used to access IO devices. This
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behaviour can be enabled with:
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cpu_lm32_set_phys_msb_ignore(env, 1);
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