Signed-off-by: Alistair Francis <alistair.fran...@xilinx.com> --- V9: - Clarify the image loading options V8: - Improve documentation V6: - Fixup documentation V4: - Re-write to be more comprehensive
docs/generic-loader.txt | 63 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 docs/generic-loader.txt diff --git a/docs/generic-loader.txt b/docs/generic-loader.txt new file mode 100644 index 0000000..16c11ee --- /dev/null +++ b/docs/generic-loader.txt @@ -0,0 +1,63 @@ +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> + + <addr> - The address to store the data or the value to use as the + CPU's PC. + <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> - This will cause the CPU to be reset and the PC to be set to + the value of addr. + +For all values both hex and decimal values are allowed. 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 + +Loading Files +------------- +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 required if you aren't loading an ELF. + <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 + where the image is stored or in the case of an ELF file to + the value in the header. This option should only be used + for the boot image. + This will also cause the image to be written to the specified + CPUs address space. + <force-raw> - Forces the file to be treated as a raw image. This can be + used to specify the load address of ELF files. + +For all values both hex and decimal values are allowed. 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 -- 2.7.4