gem5: integrate fs_bigLITTLE.py into run

README.adoc

@@ -6390,9 +6390,9 @@ The out of build tree is required, because otherwise Buildroot would copy the ou
 
 === gem5 fs_bigLITTLE
 
-TODO integrate into `run`. There is no way to pass command line arguments except by hacking the script, this is a pre-requisite for good integration.
+By default, we use `configs/example/fs.py` script.
 
-This system is more representative of ARM, which almost always has the big little cluster.
+The `-X-b` option enables the alternative `configs/example/arm/fs_bigLITTLE.py` script instead.
 
 First apply:
 
@@ -6418,14 +6418,20 @@ index 7d66c03a6..d71e714fe 100644
 then:
 
 ....
-./fs-biglittle
+./run -aA -g -X-b
 ....
 
-Source: link:fs-biglittle[]
+Advantages over `fs.py`:
 
-Boot messages start at 5 minutes, boot finishes at 10 minutes and gives a shell.
+* more representative of mobile ARM SoCs, which almost always have  big little cluster
+* simpler than `fs.py`, and therefore easier to understand and modify
 
-`cat /proc/cpuinfo` shows 4 identical CPUs instead of 2 of two different types, likely because gem5 does not expose some informational register much like the caches: https://www.mail-archive.com/gem5-users@gem5.org/msg15426.html `config.ini` does show that the two big ones are `DerivO3CPU` and the small ones are `MinorCPU`.
+Disadvantages over `fs.py`:
+
+* only works for ARM, not other archs
+* not as many configuration options as `fs.py`, many things are hardcoded
+
+We setup 2 big and 2 small CPUs, but `cat /proc/cpuinfo` shows 4 identical CPUs instead of 2 of two different types, likely because gem5 does not expose some informational register much like the caches: https://www.mail-archive.com/gem5-users@gem5.org/msg15426.html `config.ini` does show that the two big ones are `DerivO3CPU` and the small ones are `MinorCPU`.
 
 TODO: why is the `--dtb` required despite `fs_bigLITTLE.py` having a DTB generation capability? Without it, nothing shows on terminal, and the simulation terminates with `simulate() limit reached  @  18446744073709551615`. The magic `vmlinux.vexpress_gem5_v1.20170616` works however without a DTB.
 

fs-biglittle

@@ -1,13 +0,0 @@
-#!/usr/bin/env bash
-. common
-set_common_vars -L "${common_linux_variant}" -M "${common_gem5_variant}" aarch64 true
-M5_PATH="${common_gem5_system_dir}" \
-  "${common_gem5_build_dir}/ARM/gem5.opt" \
-  "${common_gem5_default_src_dir}/configs/example/arm/fs_bigLITTLE.py" \
-  --big-cpus=2 \
-  --caches \
-  --disk="${common_images_dir}/rootfs.ext2" \
-  --dtb "${common_gem5_system_dir}/arm/dt/armv8_gem5_v1_big_little_2_2.dtb" \
-  --kernel="${common_vmlinux}" \
-  --little-cpus=2 \
-;

run

@@ -18,8 +18,10 @@ extra_append='console_msg_format=syslog nokaslr norandmaps printk.devkmsg=on pri
 extra_append_after_dash=
 extra_flags=
 extra_flags_qemu=
+extra_opts=
 gem5=false
 gem5opts=
+gem5_fsbiglittle=false
 lkmc_eval=
 initrd=false
 initramfs=false
@@ -34,7 +36,7 @@ trace_enabled=false
 # just to prevent QEMU from emitting a warning that '' is not valid.
 trace_type=pr_manager_run
 vnc=
-while getopts a:c:DdE:e:F:f:G:ghIiKkL:M:m:n:PT:U:uVx OPT; do
+while getopts a:c:DdE:e:F:f:G:ghIiKkL:M:m:n:PT:U:uVX:x OPT; do
   case "$OPT" in
     a)
       arch="$OPTARG"
@@ -114,6 +116,9 @@ while getopts a:c:DdE:e:F:f:G:ghIiKkL:M:m:n:PT:U:uVx OPT; do
     u)
       tmux=true
       ;;
+    X)
+      extra_opts="${extra_opts} ${OPTARG}"
+      ;;
     x)
       nographic=false
       ;;
@@ -128,6 +133,17 @@ while getopts a:c:DdE:e:F:f:G:ghIiKkL:M:m:n:PT:U:uVx OPT; do
 done
 shift "$(($OPTIND - 1))"
 extra_flags="$extra_flags $@"
+OPTIND=1
+while getopts b OPT "$extra_opts"; do
+  case "$OPT" in
+    b)
+      gem5_fsbiglittle=true
+      ;;
+    ?)
+      exit 2
+      ;;
+  esac
+done
 set_common_vars -L "$common_linux_variant" -M "$common_gem5_variant" -n "$common_run_id" "$arch" "$gem5"
 if "$debug" && "$kvm"; then
   echo 'error: -d and -K are incompatible' 1>&2
@@ -176,6 +192,21 @@ ${debug_vm} \
 --debug-file=trace.txt \\
 ${gem5opts} \
 -d '${common_m5out_dir}' \\
+"
+  if "$gem5_fsbiglittle"; then
+      cmd="${gem5_common} \
+"${common_gem5_default_src_dir}/configs/example/arm/fs_bigLITTLE.py" \
+--big-cpus=2 \\
+--cpu-type=atomic \\
+--disk="${common_images_dir}/rootfs.ext2" \\
+--dtb "${common_gem5_system_dir}/arm/dt/armv8_gem5_v1_big_little_2_2.dtb" \\
+--kernel="${common_vmlinux}" \\
+--little-cpus=2 \\
+${extra_flags} \\
+"
+  else
+    gem5_common="\
+${gem5_common} \
 '${common_gem5_src_dir}/configs/example/fs.py' \\
 --disk-image='${common_images_dir}/rootfs.ext2' \\
 --kernel='${common_vmlinux}' \\
@@ -183,24 +214,25 @@ ${gem5opts} \
 --num-cpus='${cpus}' \\
 --script='${readfile_file}' \\
 "
-  if [ "$arch" = x86_64 ]; then
+    if [ "$arch" = x86_64 ]; then
-    if "$kvm"; then
+      if "$kvm"; then
-      extra_flags="$extra_flags --cpu-type=X86KvmCPU"
+        extra_flags="$extra_flags --cpu-type=X86KvmCPU"
-    fi
+      fi
-    cmd="\
+      cmd="\
 ${gem5_common} \
 --command-line='earlyprintk=ttyS0 console=ttyS0 lpj=7999923 root=/dev/sda ${extra_append}' \\
 ${extra_flags} \
 "
-  elif [ "$arch" = arm ] || [ "$arch" = aarch64 ]; then
+    elif [ "$arch" = arm ] || [ "$arch" = aarch64 ]; then
-    # TODO why is it mandatory to pass mem= here? Not true for QEMU.
+      # TODO why is it mandatory to pass mem= here? Not true for QEMU.
-    # Anything smaller than physical blows up as expected, but why can't it auto-detect the right value?
+      # Anything smaller than physical blows up as expected, but why can't it auto-detect the right value?
-    cmd="${gem5_common} \
+      cmd="${gem5_common} \
 --command-line='earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 rw loglevel=8 mem=${memory} root=/dev/sda ${extra_append}' \\
 --dtb-file='${common_gem5_system_dir}/arm/dt/$([ "$arch" = arm ] && echo "armv7_gem5_v1_${cpus}cpu" || echo "armv8_gem5_v1_${cpus}cpu").dtb' \\
 --machine-type=VExpress_GEM5_V1 \\
 ${extra_flags} \
 "
+    fi
   fi
 else
   mkdir -p "$common_qemu_run_dir"

run-usage.adoc

@@ -6,57 +6,62 @@
 
 [options="header"]
 |===
-|Name |Argument name |Description
+|Name   |Argument name |Description
-|`-a` |`ARCH`        |Run architecture `ARCH`.
+|`-a`   |`ARCH`        |Run architecture `ARCH`.
-|`-c` |`NCPUS`       |Emulate `NCPUS` guest CPUs.
+|`-c`   |`NCPUS`       |Emulate `NCPUS` guest CPUs.
-|`-D` |              |Run GDB on the emulator itself.
+|`-D`   |              |Run GDB on the emulator itself.
-|`-d` |              |Wait for GDB to connect before starting execution.
+|`-d`   |              |Wait for GDB to connect before starting execution.
-|`-E` |`CMDSTR`      |Replace the normal init with a minimal init that just evals
+|`-E`   |`CMDSTR`      |Replace the normal init with a minimal init that just evals
-                      with given `CMDSTR` bash command string. Example:
+                        with given `CMDSTR` bash command string. Example:
-                      `-E 'insmod /hello.ko;'`
+                        `-E 'insmod /hello.ko;'`
-|`-e` |`CLI_OPTIONS` |Pass an extra Linux kernel command line options,
+|`-e`   |`CLI_OPTIONS` |Pass an extra Linux kernel command line options,
-                      and place them before the dash separator `-`.
+                        and place them before the dash separator `-`.
-                      Only options that come before the `-`, i.e. "standard"
+                        Only options that come before the `-`, i.e. "standard"
-                      options, should be passed with this option.
+                        options, should be passed with this option.
-                      Example: `./run -a arm -e 'init=/poweroff.out'`
+                        Example: `./run -a arm -e 'init=/poweroff.out'`
-|`-F` |`CMDSTR`      |Much like `-f`, but base64 encodes the string.
+|`-F`   |`CMDSTR`      |Much like `-f`, but base64 encodes the string.
-                      Mnemonic: `-F` is to `-f` what `-E` is to `-e`.
+                        Mnemonic: `-F` is to `-f` what `-E` is to `-e`.
-|`-f` |`CLI_OPTIONS` |Pass an extra Linux kernel command line options,
+|`-f`   |`CLI_OPTIONS` |Pass an extra Linux kernel command line options,
-                      add a dash `-` separator, and place the options after the dash.
+                        add a dash `-` separator, and place the options after the dash.
-                      Intended for custom options understood by our `init` scripts,
+                        Intended for custom options understood by our `init` scripts,
-                      most of which are prefixed by `lkmc_`, e.g.:
+                        most of which are prefixed by `lkmc_`, e.g.:
-                      `./run -f 'lkmc_eval="wget google.com" lkmc_lala=y'`
+                        `./run -f 'lkmc_eval="wget google.com" lkmc_lala=y'`
-                      Mnenomic: comes after `-e`.
+                        Mnenomic: comes after `-e`.
-|`-G` |              |Pass extra options to the gem5 executable.
+|`-G`   |              |Pass extra options to the gem5 executable.
-                      Do not confuse with the arguments passed to config scripts,
+                        Do not confuse with the arguments passed to config scripts,
-                      like `fs.py`. Example: `./run -G '--debug-flags=Exec --debug' -g`
+                        like `fs.py`. Example: `./run -G '--debug-flags=Exec --debug' -g`
-|`-g` |              |Use gem5 instead of QEMU.
+|`-g`   |              |Use gem5 instead of QEMU.
-|`-h` |              |Show this help message.
+|`-h`   |              |Show this help message.
-|`-I` |              |Run with initramfs.
+|`-I`   |              |Run with initramfs.
-|`-i` |              |Run with initrd.
+|`-i`   |              |Run with initrd.
-|`-K` |              |Use KVM. Only works if guest arch == host arch.
+|`-K`   |              |Use KVM. Only works if guest arch == host arch.
-|`-k` |              |Enable KGDB.
+|`-k`   |              |Enable KGDB.
-|`-L` |              |Linux kernel build variant.
+|`-L`   |              |Linux kernel build variant.
-|`-m` |              |Set the memory size of the guest. E.g.: `-m 512M`. Default: `256M`.
+|`-m`   |              |Set the memory size of the guest. E.g.: `-m 512M`. Default: `256M`.
-                      The default is the minimum amount that boots all archs without extra
+                        The default is the minimum amount that boots all archs without extra
-                      options added. Anything lower will lead some arch to fail to boot.
+                        options added. Anything lower will lead some arch to fail to boot.
-                      Any
+                        Any
-|`-n` |              |Run ID.
+|`-n`   |              |Run ID.
-|`-P` |              |Run the downloaded prebuilt images.
+|`-P`   |              |Run the downloaded prebuilt images.
-|`-T` |`TRACE_TYPES` |Set trace events to be enabled.
+|`-T`   |`TRACE_TYPES` |Set trace events to be enabled.
-                      If not given, gem5 tracing is completely disabled, while QEMU tracing
+                        If not given, gem5 tracing is completely disabled, while QEMU tracing
-                      is enabled but uses default traces that are very rare and don't affect
+                        is enabled but uses default traces that are very rare and don't affect
-                      performance. `./configure --enable-trace-backends=simple` seems to enable
+                        performance. `./configure --enable-trace-backends=simple` seems to enable
-                      some traces by default, e.g. `pr_manager_run`, and I don't know how to
+                        some traces by default, e.g. `pr_manager_run`, and I don't know how to
-                      get rid of them.
+                        get rid of them.
-|`-U` |              |Pass extra parameters to the program running on the `-u` tmux split.
+|`-U`   |              |Pass extra parameters to the program running on the `-u` tmux split.
-|`-u` |              |Create a tmUx split the window.
+|`-u`   |              |Create a tmUx split the window.
-                      You must already be inside of a `tmux` session to use this option.
+                        You must already be inside of a `tmux` session to use this option.
-                      * on the main window, run the emulator as usual
+                        * on the main window, run the emulator as usual
-                      * on the split:
+                        * on the split:
-                      ** if on QEMU and `-d` is given, GDB
+                        ** if on QEMU and `-d` is given, GDB
-                      ** if on gem5, the gem5 terminal
+                        ** if on gem5, the gem5 terminal
-|`-V` |              |Run QEMU with VNC instead of the default SDL.
+|`-V`   |              |Run QEMU with VNC instead of the default SDL.
-                      Connect to it with: `vinagre localhost:5900`.
+                        Connect to it with: `vinagre localhost:5900`.
-|`-x` |              |Run in graphic mode. Mnemonic: X11.
+|`-X`   |`EXTRA_OPTS`  |Extra options that did not fit into `A-z`!
+                        This string is parsed by `getopt` on a separate parse step with different
+                        meanings for each flag.
+|`-X-b` |              |Use `fs_bigLITTLE.py` instead of `fs.py` on gem5 simulation.
+                       Ignored by QEMU.
+|`-x`   |              |Run in graphic mode. Mnemonic: X11.
 |===