[mirror_qemu.git] / docs / generic-loader.txt

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. 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
                  CPU's address space. If not specified, the default is CPU 0.
    <force-raw> - Forces the file to be treated as a raw image. This can be
                  used to specify the load address of ELF files.

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
Commit	Line	Data
03bf1953 AF	1	Copyright (c) 2016 Xilinx Inc.
	2
	3	This work is licensed under the terms of the GNU GPL, version 2 or later. See
	4	the COPYING file in the top-level directory.
	5
	6
	7	The 'loader' device allows the user to load multiple images or values into
	8	QEMU at startup.
	9
	10	Loading Data into Memory Values
	11	---------------------
	12	The loader device allows memory values to be set from the command line. This
	13	can be done by following the syntax below:
	14
	15	-device loader,addr=<addr>,data=<data>,data-len=<data-len>
	16	[,data-be=<data-be>][,cpu-num=<cpu-num>]
	17
	18	<addr> - The address to store the data in.
	19	<data> - The value to be written to the address. The maximum size of
	20	the data is 8 bytes.
	21	<data-len> - The length of the data in bytes. This argument must be
	22	included if the data argument is.
	23	<data-be> - Set to true if the data to be stored on the guest should be
	24	written as big endian data. The default is to write little
	25	endian data.
	26	<cpu-num> - The number of the CPU's address space where the data should
	27	be loaded. If not specified the address space of the first
	28	CPU is used.
	29
	30	All values are parsed using the standard QemuOps parsing. This allows the user
	31	to specify any values in any format supported. By default the values
	32	will be parsed as decimal. To use hex values the user should prefix the number
	33	with a '0x'.
	34
	35	An example of loading value 0x8000000e to address 0xfd1a0104 is:
	36	-device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4
	37
	38	Setting a CPU's Program Counter
	39	---------------------
	40	The loader device allows the CPU's PC to be set from the command line. This
	41	can be done by following the syntax below:
	42
	43	-device loader,addr=<addr>,cpu-num=<cpu-num>
	44
	45	<addr> - The value to use as the CPU's PC.
	46	<cpu-num> - The number of the CPU whose PC should be set to the
	47	specified value.
	48
	49	All values are parsed using the standard QemuOps parsing. This allows the user
	50	to specify any values in any format supported. By default the values
	51	will be parsed as decimal. To use hex values the user should prefix the number
	52	with a '0x'.
	53
	54	An example of setting CPU 0's PC to 0x8000 is:
	55	-device loader,addr=0x8000,cpu-num=0
	56
	57	Loading Files
	58	---------------------
	59	The loader device also allows files to be loaded into memory. This can be done
	60	similarly to setting memory values. The syntax is shown below:
	61
	62	-device loader,file=<file>[,addr=<addr>][,cpu-num=<cpu-num>][,force-raw=<raw>]
	63
	64	<file> - A file to be loaded into memory
65	<addr> - The addr in memory that the file should be loaded. This is
66	ignored if you are using an ELF (unless force-raw is true).
67	This is required if you aren't loading an ELF.
68	<cpu-num> - This specifies the CPU that should be used. This is an
69	optional argument and will cause the CPU's PC to be set to
70	where the image is stored or in the case of an ELF file to
71	the value in the header. This option should only be used
72	for the boot image.
73	This will also cause the image to be written to the specified
74	CPU's address space. If not specified, the default is CPU 0.
75	<force-raw> - Forces the file to be treated as a raw image. This can be
76	used to specify the load address of ELF files.
77
78	All values are parsed using the standard QemuOps parsing. This allows the user
79	to specify any values in any format supported. By default the values
80	will be parsed as decimal. To use hex values the user should prefix the number
81	with a '0x'.
82
83	An example of loading an ELF file which CPU0 will boot is shown below:
84	-device loader,file=./images/boot.elf,cpu-num=0