docs/system: Move the RISC-V -bios information to removed

QEMU 5.1 changed the behaviour of the default boot for the RISC-V virt
and sifive_u machines. This patch moves that change from the
deprecated.rst file to the removed-features.rst file and the
target-riscv.rst.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 4f1c261e7f69045ab8bb8926d85fe1d35e48ea5b.1620081256.git.alistair.francis@wdc.com

docs/system/deprecated.rst

@@ -52,25 +52,6 @@ pcspk-audiodev=<name>``.
 ``tty`` and ``parport`` are aliases that will be removed. Instead, the
 actual backend names ``serial`` and ``parallel`` should be used.
 
-RISC-V ``-bios`` (since 5.1)
-''''''''''''''''''''''''''''
-
-QEMU 4.1 introduced support for the -bios option in QEMU for RISC-V for the
-RISC-V virt machine and sifive_u machine. QEMU 4.1 had no changes to the
-default behaviour to avoid breakages.
-
-QEMU 5.1 changes the default behaviour from ``-bios none`` to ``-bios default``.
-
-QEMU 5.1 has three options:
- 1. ``-bios default`` - This is the current default behavior if no -bios option
-      is included. This option will load the default OpenSBI firmware automatically.
-      The firmware is included with the QEMU release and no user interaction is
-      required. All a user needs to do is specify the kernel they want to boot
-      with the -kernel option
- 2. ``-bios none`` - QEMU will not automatically load any firmware. It is up
-      to the user to load all the images they need.
- 3. ``-bios <file>`` - Tells QEMU to load the specified file as the firmwrae.
-
 Short-form boolean options (since 6.0)
 ''''''''''''''''''''''''''''''''''''''
 

docs/system/removed-features.rst

@@ -126,6 +126,11 @@ devices.  Drives the board doesn't pick up can no longer be used with
 This option was undocumented and not used in the field.
 Use `-device usb-ccid`` instead.
 
+RISC-V firmware not booted by default (removed in 5.1)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+QEMU 5.1 changes the default behaviour from ``-bios none`` to ``-bios default``
+for the RISC-V ``virt`` machine and ``sifive_u`` machine.
 
 QEMU Machine Protocol (QMP) commands
 ------------------------------------

docs/system/target-riscv.rst

@@ -70,5 +70,16 @@ undocumented; you can get a complete list by running
    riscv/shakti-c
    riscv/sifive_u
 
-RISC-V CPU features
+RISC-V CPU firmware
 -------------------
+
+When using the ``sifive_u`` or ``virt`` machine there are three different
+firmware boot options:
+1. ``-bios default`` - This is the default behaviour if no -bios option
+is included. This option will load the default OpenSBI firmware automatically.
+The firmware is included with the QEMU release and no user interaction is
+required. All a user needs to do is specify the kernel they want to boot
+with the -kernel option
+2. ``-bios none`` - QEMU will not automatically load any firmware. It is up
+to the user to load all the images they need.
+3. ``-bios <file>`` - Tells QEMU to load the specified file as the firmware.