Running Instructions

In this page, we will explain how to run and configure SimpleSSD.

Execution of SimpleSSD-FullSystem

Build SimpleSSD-FullSystem using instruction.

Now you can start simulation using following command (Assume ARM architecture):

./build/ARM/gem5.opt --debug-flag=M5Print --debug-file=debug.txt \
./configs/example/fs.py --kernel=aarch64-linux-4.9.92 \
--dtb-file=armv8_gem5_v1_4cpu.dtb --machine-type=VExpress_GEM5_V1 \
--num-cpu=4 --cpu-clock=2GHz --caches --l2cache --cpu-type=AtomicSimpleCPU \
--mem-size=4GB --mem-type=DDR4_2400_8x8 \
--ssd-interface=nvme --ssd-config=./src/dev/storage/simplessd/config/sample.cfg

Note

If you want to use disk image provided by CAMELab (Assume ARM architecture), append --disk-image=linaro-aarch64-linux.img to the end of the above command.

Note

If you want to use SATA or UFS interface as SimpleSSD interface, you need to append --root-device=/dev/sdb1 to the end of the above command. This is because gem5’s IDE controller is initialized after the SATA or UFS controller. You can ignore this note if you try to boot gem5 using SimpleSSD, not using the IDE controller.

Let’s check all the options used in above command line. Command line for executing gem5 has following format:

./build/<arch>/gem5.<build mode> [gem5 options] <simulation script> [script options]

<arch> can be ARM or X86, because SimpleSSD only supports these two architectures. <build mode> can be debug, opt, fast, prof, and perf. For more details, check gem5 build instruction.

<simulation script> defines simulation hardware and software system. gem5 provides example simulation scripts (in ./configs/example). We modified default full system simulation script (./configs/example/fs.py) to enable SimpleSSD inside gem5.

Following sections describes each options used in command line.

Options for gem5 executable

In above example, --debug-flag and --debug-file options are used. Here is the description of each options, including commonly used other options.

Options Description
--debug-flag Set comma-separated list of debug flags. This determine which debug log of hardware module will be printed.
--debug-file Set file to store debug log.
--outdir, -d Set directory to store all simulation outputs.
--redirect-stdout, -r Redirect stdout and stderr of gem5 to simout file. File name can be changed using --stdout-file option.
--redirect-stderr, -e Redirect stderr of gem5 to simerr file. File name can be changed using --stderr-file option.

For more options, use ./build/ARM/gem5.opt --help or check here.

Options for simulation script

For options for ./configs/example/fs.py, check following table.

Options Description
--kernel Set kernel image to use. This path is relative to $M5_PATH/binaries
--num-cpu Set # CPU of system to simulate. If you are using ARM, you should use same value defined in dtb file. If you are using X86, simulation may unstable when two or more CPUs exist in system.
--cpu-type Set CPU model to use. Default is AtomicSimpleCPU. Possible values can be checked using --list-cpu-type option. SimpleSSD support all CPU modes provided by gem5. If you are using X86, simulation may unstable when using other CPU models not AtomicSimpleCPU.
--cpu-clock Set clock speed (frequency) of CPU.
--caches Enable private L1I and L1D caches. You can change size and associativity using following options: --l1i_size, --l1d_size, --l1i_assoc and --l1d_assoc.
--l2cache Enable shared L2 cache. You can change size and associativity using following options: --l2_size and --l2_assoc.
--mem-size Set capacity of system memory (DRAM).
--mem-type Set memory model to use. Possible values can be checked using --list-mem-type option.
--script Set script file automatically executed after boot.
--root-device Set disk partition to mount as root (e.g., /dev/sda1).
--disk-image Set disk image to use as OS image. Default is x86root.img when using X86 and linux-aarch32-ael.img or linaro-minimal-aarch64.img when using ARM. This path is relative to $M5_PATH/disks

Following options are ARM architecture specific, so you don’t need to specify when using X86 architecture.

Options Description
--dtb-file Set compiled DeviceTree (dtb) file.
--machine-type Set hardware platform to simulate. You can check possible values using --list-machine-type, but SimpleSSD only supports VExpress_GEM5_V1.

Following options are added by SimpleSSD.

Options Description
--ssd-interface Set host interface protocol/hardware to use. Default is nvme. Possible values: nvme, ocssd1, ocssd2, sata and ufs. ufs only works on ARM architecture.
--ssd-config Set SimpleSSD configuration file. This path is relative to current working directory.

For more options, use ./build/ARM/gem5.opt ./configs/example/fs.py --help or check here. For supported Linux Kernel versions, see Build Linux Kernel for gem5.

SimpleSSD configuration file

Sample configuration file is provided with source code. See src/dev/storage/simplessd/config/sample.cfg file. You can also download configuration files which are used in validation process from here.

Each option is explained in configuration file.

Execution of SimpleSSD-Standalone

Build SimpleSSD-Standalone using instruction.

Now you can start simulation using following command.

./simplessd-standalone ./config/sample.cfg ./simplessd/config/sample.cfg

Execution of SimpleSSD-Standalone is quite simple because all simulation options are defined in a separated file. First file (./config/sample.cfg) defines simulation configuration. Second file (./simplessd/config/sample.cfg) defines SSD configuration. For SSD configuration, see above section.

Simulation configuration

Sample simulation file is provided with source code. See config/sample.cfg file for options and explanations.