diff --git a/init-environment.html b/init-environment.html
index 9a1d129..23804fe 100644
--- a/init-environment.html
+++ b/init-environment.html
@@ -459,29 +459,31 @@ pre{ white-space:pre }
-
The kernel parses parameters from the kernel command line up to "-"; if it doesn’t recognize a parameter and it doesn’t contain a '.', the parameter gets passed to init: parameters with '=' go into init’s environment, others are passed as command line arguments to init. Everything after "-" is passed as an argument to init.
+
The kernel parses parameters from the kernel command line up to "--"; if it doesn’t recognize a parameter and it doesn’t contain a '.', the parameter gets passed to init: parameters with '=' go into init’s environment, others are passed as command line arguments to init. Everything after "--" is passed as an argument to init.
-
./run --kernel-cli 'init=/lkmc/linux/init_env_poweroff.out' --kernel-cli-after-dash 'asdf=qwer zxcv'
+
./run --kernel-cli 'init=/lkmc/linux/init_env_poweroff.out loglevel=8 go_in_env=val1 with_dot.before=val2' \
+ --kernel-cli-after-dash 'go_in_arg=val3 with_dot.after=val4 zxcv'
-
init=/lkmc/linux/init_env_poweroff.out console=ttyS0 - lkmc_home=/lkmc asdf=qwer zxcv
+
<6>[ 0.000000] Command line: root=/dev/vda nopat console_msg_format=syslog nokaslr norandmaps panic=-1 printk.devkmsg=on printk.time=y rw
+ init=/lkmc/linux/init_env_poweroff.out loglevel=8 go_in_env=val1 with_dot.before=val2 -- go_in_arg=val3 with_dot.after=val4 zxcv
@@ -489,38 +491,55 @@ pre{ white-space:pre }
-
args:
-/lkmc/linux/init_env_poweroff.out
--
-zxcv
-
-env:
-HOME=/
-TERM=linux
-lkmc_home=/lkmc
-asdf=qwer
+
<6>[ 2.728992] Run /lkmc/linux/init_env_poweroff.out as init process
+<7>[ 2.729587] with arguments:
+<7>[ 2.729820] /lkmc/linux/init_env_poweroff.out
+<7>[ 2.730085] lkmc_home=/lkmc
+<7>[ 2.730259] go_in_arg=val3
+<7>[ 2.730432] with_dot.after=val4
+<7>[ 2.730623] zxcv
+<7>[ 2.730767] with environment:
+<7>[ 2.730960] HOME=/
+<7>[ 2.731115] TERM=linux
+<7>[ 2.731267] go_in_env=val
-
-
As of the Linux kernel v5.7 (possibly earlier, I’ve skipped a few releases), boot also shows the init arguments and environment very clearly, which is a great addition:
+
Tested as of the Linux kernel v5.7 and possibly earlier, boot also shows the init arguments and environment very clearly when using printk at loglevel=8, which is a great addition:
-
<6>[ 0.309984] Run /sbin/init as init process
-<7>[ 0.309991] with arguments:
-<7>[ 0.309997] /sbin/init
-<7>[ 0.310004] nokaslr
-<7>[ 0.310010] -
-<7>[ 0.310016] with environment:
-<7>[ 0.310022] HOME=/
-<7>[ 0.310028] TERM=linux
-<7>[ 0.310035] earlyprintk=pl011,0x1c090000
-<7>[ 0.310041] lkmc_home=/lkmc
+
<6>[ 2.777265] Run /lkmc/linux/init_env_poweroff.out as init process
+<7>[ 2.777729] with arguments:
+<7>[ 2.777953] /lkmc/linux/init_env_poweroff.out
+<7>[ 2.778212] lkmc_home=/lkmc
+<7>[ 2.778391] go_in_arg=val2
+<7>[ 2.778554] zxcv
+<7>[ 2.778705] with environment:
+<7>[ 2.778901] HOME=/
+<7>[ 2.779065] TERM=linux
+<7>[ 2.779223] go_in_env=val1
+
+
As we can see, the passing of environment variables to init is a bit wonky:
+
+
+
+
so things can always break in future kernel releases… The only way to guard from this a bit is to use some unique prefix and hope the kernel never decides to use it. We of course use lkmc_* for our variables.
+
+
+
And it is also impossible to pass environment variables that contain dots in them: our with_dot.before is simply gone. Not a common use case, but still, quite insane.
+
diff --git a/kernel-command-line-parameters.html b/kernel-command-line-parameters.html
index 6cf7dda..ac20ad7 100644
--- a/kernel-command-line-parameters.html
+++ b/kernel-command-line-parameters.html
@@ -502,7 +502,7 @@ pre{ white-space:pre }
When dealing with real boards, extra command line options are provided on some magic bootloader configuration file, e.g.:
diff --git a/replace-init.html b/replace-init.html
index 0fb37fa..cac9ab2 100644
--- a/replace-init.html
+++ b/replace-init.html
@@ -473,6 +473,14 @@ pre{ white-space:pre }
This just counts every second forever and does not give you a shell.
+
And to pass command line arguments to the program, you can use --kernel-cli-after-dash:
+
+
+
+
./run --kernel-cli 'init=/bin/sh' --kernel-cli-after-dash '-c "echo asdf; pwd; ls"'
+
+
+
This method is not very flexible however, as it is hard to reliably pass multiple commands and command line arguments to the init with it, as explained at: Section 7.4, “Init environment”.
diff --git a/seq-file.html b/seq-file.html
index 7ca564d..6ecfbb4 100644
--- a/seq-file.html
+++ b/seq-file.html
@@ -459,6 +459,27 @@ pre{ white-space:pre }
+
TODO these examples broke in kernel 5.0 and we didn’t notice because they just added a flimsy warning and nothing else:
+
+
+
+
Fix with ifdef for kernel 4/5. The error message is:
+
+
+
+
seq_file: buggy .next function next [module-name] did not update position index
+
+
+
Writing trivial read File operations is repetitive and error prone. The seq_file API makes the process much easier for those trivial cases:
diff --git a/submodules/buildroot b/submodules/buildroot
index b8c14b5..ccebc33 160000
--- a/submodules/buildroot
+++ b/submodules/buildroot
@@ -1 +1 @@
-Subproject commit b8c14b5bcac5c1a742401ece15fafe755a06ab03
+Subproject commit ccebc33040455ffb79038161e3bd22f428ed174e