docs: move generic-loader documentation into the main manual

We might as well surface this useful information in the manual so
users can find it easily. It is a fairly simple conversion to rst with
the only textual fixes being QemuOps to QemuOpts.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210303173642.3805-6-alex.bennee@linaro.org>
This commit is contained in:
Alex Bennée 2021-03-03 17:36:40 +00:00
parent a33ff6d2c6
commit 70f2011015
4 changed files with 119 additions and 93 deletions

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@ -2020,7 +2020,7 @@ M: Alistair Francis <alistair@alistair23.me>
S: Maintained
F: hw/core/generic-loader.c
F: include/hw/core/generic-loader.h
F: docs/generic-loader.txt
F: docs/system/generic-loader.rst
Guest Loader
M: Alex Bennée <alex.bennee@linaro.org>

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@ -1,92 +0,0 @@
Copyright (c) 2016 Xilinx Inc.
This work is licensed under the terms of the GNU GPL, version 2 or later. See
the COPYING file in the top-level directory.
The 'loader' device allows the user to load multiple images or values into
QEMU at startup.
Loading Data into Memory Values
-------------------------------
The loader device allows memory values to be set from the command line. This
can be done by following the syntax below:
-device loader,addr=<addr>,data=<data>,data-len=<data-len>
[,data-be=<data-be>][,cpu-num=<cpu-num>]
<addr> - The address to store the data in.
<data> - The value to be written to the address. The maximum size of
the data is 8 bytes.
<data-len> - The length of the data in bytes. This argument must be
included if the data argument is.
<data-be> - Set to true if the data to be stored on the guest should be
written as big endian data. The default is to write little
endian data.
<cpu-num> - The number of the CPU's address space where the data should
be loaded. If not specified the address space of the first
CPU is used.
All values are parsed using the standard QemuOps parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of loading value 0x8000000e to address 0xfd1a0104 is:
-device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4
Setting a CPU's Program Counter
-------------------------------
The loader device allows the CPU's PC to be set from the command line. This
can be done by following the syntax below:
-device loader,addr=<addr>,cpu-num=<cpu-num>
<addr> - The value to use as the CPU's PC.
<cpu-num> - The number of the CPU whose PC should be set to the
specified value.
All values are parsed using the standard QemuOps parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of setting CPU 0's PC to 0x8000 is:
-device loader,addr=0x8000,cpu-num=0
Loading Files
-------------
The loader device also allows files to be loaded into memory. It can load ELF,
U-Boot, and Intel HEX executable formats as well as raw images. The syntax is
shown below:
-device loader,file=<file>[,addr=<addr>][,cpu-num=<cpu-num>][,force-raw=<raw>]
<file> - A file to be loaded into memory
<addr> - The memory address where the file should be loaded. This is
required for raw images and ignored for non-raw files.
<cpu-num> - This specifies the CPU that should be used. This is an
optional argument and will cause the CPU's PC to be set to
the memory address where the raw file is loaded or the entry
point specified in the executable format header. This option
should only be used for the boot image.
This will also cause the image to be written to the specified
CPU's address space. If not specified, the default is CPU 0.
<force-raw> - Setting force-raw=on forces the file to be treated as a raw
image. This can be used to load supported executable formats
as if they were raw.
All values are parsed using the standard QemuOps parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of loading an ELF file which CPU0 will boot is shown below:
-device loader,file=./images/boot.elf,cpu-num=0
Restrictions and ToDos
----------------------
- At the moment it is just assumed that if you specify a cpu-num then you
want to set the PC as well. This might not always be the case. In future
the internal state 'set_pc' (which exists in the generic loader now) should
be exposed to the user so that they can choose if the PC is set or not.

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@ -0,0 +1,117 @@
..
Copyright (c) 2016, Xilinx Inc.
This work is licensed under the terms of the GNU GPL, version 2 or later. See
the COPYING file in the top-level directory.
Generic Loader
--------------
The 'loader' device allows the user to load multiple images or values into
QEMU at startup.
Loading Data into Memory Values
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The loader device allows memory values to be set from the command line. This
can be done by following the syntax below::
-device loader,addr=<addr>,data=<data>,data-len=<data-len> \
[,data-be=<data-be>][,cpu-num=<cpu-num>]
``<addr>``
The address to store the data in.
``<data>``
The value to be written to the address. The maximum size of the data
is 8 bytes.
``<data-len>``
The length of the data in bytes. This argument must be included if
the data argument is.
``<data-be>``
Set to true if the data to be stored on the guest should be written
as big endian data. The default is to write little endian data.
``<cpu-num>``
The number of the CPU's address space where the data should be
loaded. If not specified the address space of the first CPU is used.
All values are parsed using the standard QemuOps parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of loading value 0x8000000e to address 0xfd1a0104 is::
-device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4
Setting a CPU's Program Counter
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The loader device allows the CPU's PC to be set from the command line. This
can be done by following the syntax below::
-device loader,addr=<addr>,cpu-num=<cpu-num>
``<addr>``
The value to use as the CPU's PC.
``<cpu-num>``
The number of the CPU whose PC should be set to the specified value.
All values are parsed using the standard QemuOpts parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of setting CPU 0's PC to 0x8000 is::
-device loader,addr=0x8000,cpu-num=0
Loading Files
^^^^^^^^^^^^^
The loader device also allows files to be loaded into memory. It can load ELF,
U-Boot, and Intel HEX executable formats as well as raw images. The syntax is
shown below:
-device loader,file=<file>[,addr=<addr>][,cpu-num=<cpu-num>][,force-raw=<raw>]
``<file>``
A file to be loaded into memory
``<addr>``
The memory address where the file should be loaded. This is required
for raw images and ignored for non-raw files.
``<cpu-num>``
This specifies the CPU that should be used. This is an
optional argument and will cause the CPU's PC to be set to the
memory address where the raw file is loaded or the entry point
specified in the executable format header. This option should only
be used for the boot image. This will also cause the image to be
written to the specified CPU's address space. If not specified, the
default is CPU 0. <force-raw> - Setting force-raw=on forces the file
to be treated as a raw image. This can be used to load supported
executable formats as if they were raw.
All values are parsed using the standard QemuOpts parsing. This allows the user
to specify any values in any format supported. By default the values
will be parsed as decimal. To use hex values the user should prefix the number
with a '0x'.
An example of loading an ELF file which CPU0 will boot is shown below::
-device loader,file=./images/boot.elf,cpu-num=0
Restrictions and ToDos
^^^^^^^^^^^^^^^^^^^^^^
At the moment it is just assumed that if you specify a cpu-num then
you want to set the PC as well. This might not always be the case. In
future the internal state 'set_pc' (which exists in the generic loader
now) should be exposed to the user so that they can choose if the PC
is set or not.

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@ -25,6 +25,7 @@ Contents:
usb
ivshmem
linuxboot
generic-loader
vnc-security
tls
gdb