docs/system/target-riscv.rst

1 .. _RISC-V-System-emulator:
3 RISC-V System emulator
6 QEMU can emulate both 32-bit and 64-bit RISC-V CPUs. Use the
7 ``qemu-system-riscv64`` executable to simulate a 64-bit RISC-V machine,
8 ``qemu-system-riscv32`` executable to simulate a 32-bit RISC-V machine.
10 QEMU has generally good support for RISC-V guests. It has support for
12 RISC-V hardware is much more widely varying than x86 hardware. RISC-V
13 CPUs are generally built into "system-on-chip" (SoC) designs created by
23 ----------------------
25 For QEMU's RISC-V system emulation, you must specify which board
26 model you want to use with the ``-M`` or ``--machine`` option;
29 Because RISC-V systems differ so much and in fundamental ways, typically
30 operating system or firmware images intended to run on one machine
32 users who are used to the x86 world where every system looks like a
36 If you already have a system image or a kernel that works on hardware
37 and you want to boot with QEMU, check whether QEMU lists that machine
38 in its ``-machine help`` output. If it is listed, then you can probably
40 will almost certainly not boot on QEMU. (You might be able to
41 extract the file system and use that with a different kernel which
42 boots on a system that QEMU does emulate.)
51 large amounts of RAM. It also supports 64-bit CPUs.
53 Board-specific documentation
54 ----------------------------
56 Unfortunately many of the RISC-V boards QEMU supports are currently
58 ``qemu-system-riscv64 --machine help``, or
59 ``qemu-system-riscv32 --machine help``.
69    riscv/microchip-icicle-kit
70    riscv/shakti-c
74 RISC-V CPU firmware
75 -------------------
80 * ``-bios default``
82 This is the default behaviour if no ``-bios`` option is included. This option
84 with the QEMU release and no user interaction is required. All a user needs to
85 do is specify the kernel they want to boot with the ``-kernel`` option
87 * ``-bios none``
89 QEMU will not automatically load any firmware. It is up to the user to load all
92 * ``-bios <file>``
94 Tells QEMU to load the specified file as the firmware.