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Diffstat (limited to 'docs/system')
| -rw-r--r-- | docs/system/riscv/virt.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/docs/system/riscv/virt.rst b/docs/system/riscv/virt.rst index 4b16e41d7f..b33f45e5b3 100644 --- a/docs/system/riscv/virt.rst +++ b/docs/system/riscv/virt.rst @@ -53,6 +53,37 @@ with the default OpenSBI firmware image as the -bios. It also supports the recommended RISC-V bootflow: U-Boot SPL (M-mode) loads OpenSBI fw_dynamic firmware and U-Boot proper (S-mode), using the standard -bios functionality. +Using flash devices +------------------- + +By default, the first flash device (pflash0) is expected to contain +S-mode firmware code. It can be configured as read-only, with the +second flash device (pflash1) available to store configuration data. + +For example, booting edk2 looks like + +.. code-block:: bash + + $ qemu-system-riscv64 \ + -blockdev node-name=pflash0,driver=file,read-only=on,filename=<edk2_code> \ + -blockdev node-name=pflash1,driver=file,filename=<edk2_vars> \ + -M virt,pflash0=pflash0,pflash1=pflash1 \ + ... other args .... + +For TCG guests only, it is also possible to boot M-mode firmware from +the first flash device (pflash0) by additionally passing ``-bios +none``, as in + +.. code-block:: bash + + $ qemu-system-riscv64 \ + -bios none \ + -blockdev node-name=pflash0,driver=file,read-only=on,filename=<m_mode_code> \ + -M virt,pflash0=pflash0 \ + ... other args .... + +Firmware images used for pflash must be exactly 32 MiB in size. + Machine-specific options ------------------------ |