bisection: update section, add gem5 linux boot bisect script

README.adoc

@@ -15212,7 +15212,7 @@ However, for many types of crashes, it is trivial to bisect down to the offendin
 
 For example, when updating from QEMU `v2.12.0` to `v3.0.0-rc3`, the Linux kernel boot started to panic for `arm`.
 
-We then bisected it as explained at: https://stackoverflow.com/questions/4713088/how-to-use-git-bisect/22592593#22592593 with the link:qemu-bisect-boot[] script:
+We then bisected it as explained at: https://stackoverflow.com/questions/4713088/how-to-use-git-bisect/22592593#22592593 with the link:bisect-qemu-linux-boot[] script:
 
 ....
 root_dir="$(pwd)"
@@ -15220,20 +15220,20 @@ cd "$(./getvar qemu_source_dir)"
 git bisect start
 
 # Check that our test script fails on v3.0.0-rc3 as expected, and mark it as bad.
-"${root_dir}/qemu-bisect-boot"
+"${root_dir}/bisect-qemu-linux-boot"
 # Should output 1.
 echo #?
 git bisect bad
 
 # Same for the good end.
 git checkout v2.12.0
-"${root_dir}/qemu-bisect-boot"
+"${root_dir}/bisect-qemu-linux-boot"
 # Should output 0.
 echo #?
 git bisect good
 
 # This leaves us at the offending commit.
-git bisect run ../bisect-qemu-linux-boot
+git bisect run "${root_dir}/bisect-qemu-linux-boot"
 
 # Clean up after the bisection.
 git bisect reset
@@ -15241,7 +15241,10 @@ git submodule update
 "${root_dir}/build-qemu" --clean --qemu-build-id bisect
 ....
 
-TODO broken, fix: An example of Linux kernel commit bisection on gem5 boots can be found at: link:bisect-linux-boot-gem5[].
+Other bisection helpers include:
+
+* link:bisect-linux-boot-gem5[]
+* link:bisect-gem5-linux-boot[]
 
 [[path-properties]]
 === path_properties

bisect-gem5-linux-boot

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+# https://github.com/cirosantilli/linux-kernel-module-cheat#bisection
+set -eu
+cd ../..
+./build-gem5 --gem5-build-id bisect
+set +e
+# Setup for quick failures:
+# https://stackoverflow.com/questions/4713088/how-to-use-git-bisect/22592593#22592593
+timeout 5 ./run --emulator gem5 --gem5-build-id bisect --quit-after-boot
+if [ $? -ne 124 ]; then
+  exit 1
+fi

bisect-linux-boot-gem5

@@ -1,9 +1,10 @@
 #!/usr/bin/env bash
+# https://github.com/cirosantilli/linux-kernel-module-cheat#bisection
 set -eu
 ./build-linux --clean "$@"
 ./build-linux "$@"
 set +e
-./run --eval 'm5 exit' "$@" || status=$?
+./run --quit-after-boot "$@" || status=$?
 # https://stackoverflow.com/questions/4713088/how-to-use-git-bisect/22592593#22592593
 if [ "$status" -eq 125 ] || [ "$status" -gt 127 ]; then
   status=1

bisect-qemu-linux-boot

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
+# https://github.com/cirosantilli/linux-kernel-module-cheat#bisection
 set -eu
 git submodule update --recursive
 cd ../..
 ./build-qemu --arch aarch64 --qemu-build-id bisect
-./run --arch aarch64 --kernel-cli 'init=/lkmc/linux/poweroff.out' --qemu-build-id bisect
+./run --arch aarch64 --qemu-build-id bisect --quit-after-boot