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[Qemu-devel] [PATCH v4 3/3] docs: Add a generic loader explanation docum
[Qemu-devel] [PATCH v4 3/3] docs: Add a generic loader explanation document
Thu, 3 Mar 2016 11:42:11 -0800
Signed-off-by: Alistair Francis <address@hidden>
- Re-write to be more comprehensive
docs/generic-loader.txt | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
create mode 100644 docs/generic-loader.txt
diff --git a/docs/generic-loader.txt b/docs/generic-loader.txt
new file mode 100644
@@ -0,0 +1,56 @@
+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 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=<len>
+ -device loader,addr=<addr>,cpu-num=<cpu-num>
+NOTE: The loader device supports other options (see the next section) but they
+ do not apply to setting memory values and will be ignored.
+ It is also possible to mix the commands above, e.g. include the cpu-num
+ argument with the data argument.
+ <addr> - The address to store the data or the value to set the CPUs PC
+ <data> - The value to be written to the addr. The maximum size of the
+ data is 8 bytes.
+ <data-len> - The length of the data in bytes. This argument must be
+ 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> - This will cause the CPU to be reset and the PC to be set to
+ the value of addr.
+An example of loading value 0x8000000e to address 0xfd1a0104 is:
+ -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4
+The loader device also allows files to be loaded into memory. This can be done
+similarly to setting memory values. 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 addr in memory that the file should be loaded. This is
+ ignored if you are using an ELF (unless force-raw is true).
+ This is requried if you aren't loading an ELF.
+ <cpu-num> - This specifices the CPU that should be used. This is an
+ optional argument and will cause the CPU's PC to be set to
+ where the image is stored. This option should only be used
+ for the boot image.
+ <force-raw> - Forces the file to be treated as a raw image. This can be
+ used to specificy the load address of ELF files.
+An example of loading an ELF file which CPU0 will boot is shown below:
+ -device loader,file=./images/boot.elf,cpu-num=0