1.. 2 Copyright (c) 2016, Xilinx Inc. 3 4 This work is licensed under the terms of the GNU GPL, version 2 or later. See 5 the COPYING file in the top-level directory. 6 7Generic Loader 8-------------- 9 10The 'loader' device allows the user to load multiple images or values into 11QEMU at startup. 12 13Loading Data into Memory Values 14^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 15The loader device allows memory values to be set from the command line. This 16can be done by following the syntax below:: 17 18 -device loader,addr=<addr>,data=<data>,data-len=<data-len> \ 19 [,data-be=<data-be>][,cpu-num=<cpu-num>] 20 21``<addr>`` 22 The address to store the data in. 23 24``<data>`` 25 The value to be written to the address. The maximum size of the data 26 is 8 bytes. 27 28``<data-len>`` 29 The length of the data in bytes. This argument must be included if 30 the data argument is. 31 32``<data-be>`` 33 Set to true if the data to be stored on the guest should be written 34 as big endian data. The default is to write little endian data. 35 36``<cpu-num>`` 37 The number of the CPU's address space where the data should be 38 loaded. If not specified the address space of the first CPU is used. 39 40All values are parsed using the standard QemuOps parsing. This allows the user 41to specify any values in any format supported. By default the values 42will be parsed as decimal. To use hex values the user should prefix the number 43with a '0x'. 44 45An example of loading value 0x8000000e to address 0xfd1a0104 is:: 46 47 -device loader,addr=0xfd1a0104,data=0x8000000e,data-len=4 48 49Setting a CPU's Program Counter 50^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 51 52The loader device allows the CPU's PC to be set from the command line. This 53can be done by following the syntax below:: 54 55 -device loader,addr=<addr>,cpu-num=<cpu-num> 56 57``<addr>`` 58 The value to use as the CPU's PC. 59 60``<cpu-num>`` 61 The number of the CPU whose PC should be set to the specified value. 62 63All values are parsed using the standard QemuOpts parsing. This allows the user 64to specify any values in any format supported. By default the values 65will be parsed as decimal. To use hex values the user should prefix the number 66with a '0x'. 67 68An example of setting CPU 0's PC to 0x8000 is:: 69 70 -device loader,addr=0x8000,cpu-num=0 71 72Loading Files 73^^^^^^^^^^^^^ 74 75The loader device also allows files to be loaded into memory. It can load ELF, 76U-Boot, and Intel HEX executable formats as well as raw images. The syntax is 77shown below: 78 79 -device loader,file=<file>[,addr=<addr>][,cpu-num=<cpu-num>][,force-raw=<raw>] 80 81``<file>`` 82 A file to be loaded into memory 83 84``<addr>`` 85 The memory address where the file should be loaded. This is required 86 for raw images and ignored for non-raw files. 87 88``<cpu-num>`` 89 This specifies the CPU that should be used. This is an 90 optional argument and will cause the CPU's PC to be set to the 91 memory address where the raw file is loaded or the entry point 92 specified in the executable format header. This option should only 93 be used for the boot image. This will also cause the image to be 94 written to the specified CPU's address space. If not specified, the 95 default is CPU 0. 96 97``<force-raw>`` 98 Setting 'force-raw=on' forces the file to be treated as a raw image. 99 This can be used to load supported executable formats as if they 100 were raw. 101 102All values are parsed using the standard QemuOpts parsing. This allows the user 103to specify any values in any format supported. By default the values 104will be parsed as decimal. To use hex values the user should prefix the number 105with a '0x'. 106 107An example of loading an ELF file which CPU0 will boot is shown below:: 108 109 -device loader,file=./images/boot.elf,cpu-num=0 110 111Restrictions and ToDos 112^^^^^^^^^^^^^^^^^^^^^^ 113 114At the moment it is just assumed that if you specify a cpu-num then 115you want to set the PC as well. This might not always be the case. In 116future the internal state 'set_pc' (which exists in the generic loader 117now) should be exposed to the user so that they can choose if the PC 118is set or not. 119 120 121