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diff --git a/mkinitramfs.8 b/mkinitramfs.8 new file mode 100644 index 0000000..9a3ddc1 --- /dev/null +++ b/mkinitramfs.8 @@ -0,0 +1,153 @@ +.TH MKINITRAMFS 8 "2018/07/18" "initramfs\-tools" "System Administration" + +.SH NAME +mkinitramfs \- low-level tool for generating an initramfs image + +.SH SYNOPSIS +.B mkinitramfs +.RI [ option ]... +.B \-o +.IR outfile +.RI [ version ] +.br +.BR mkinitramfs " " -h + +.SH DESCRIPTION +The +.B mkinitramfs +script generates an initramfs image. +The initramfs is a compressed cpio archive. The archive can be used on a +different box of the same arch with the corresponding Linux kernel. +.B mkinitramfs +is meant for advanced usage. On your local box +.B update-initramfs +calls +.B mkinitramfs +with the relevant parameters. +.B update-initramfs +keeps sha1sum of generated initramfs. It takes care to generate backups +and eventually runs the bootloader. + +At boot time, the kernel unpacks that archive into RAM disk, mounts and +uses it as initial root file system. All finding of the root device +happens in this early userspace. + +.SH OPTIONS +.TP +\fB\-c \fI compress +Override the +.B COMPRESS +setting in +.IR initramfs.conf . + +.TP +\fB\-d \fI confdir +Set an alternate configuration directory. + +.TP +\fB\-k +Keep the temporary directory used to make the image. + +.TP +\fB\-l \fI compresslevel +Override the +.B COMPRESSLEVEL +setting in +.IR initramfs.conf . + +.TP +\fB\-o \fI outfile +Write the image to +.IR outfile . + +.TP +\fB\-r \fI root +Override the +.B ROOT +setting in +.IR initramfs.conf . + +.TP +\fB\-v +Set the verbose mode output. + +.TP +\fIversion +Set the kernel version of the initramfs image +(defaults to the running kernel). + +.TP +\fB\-h\fR, \fB\-\-help\fR +Display usage information and exit. + +.SH ENVIRONMENT +.B mkinitramfs +honours the +.B TMPDIR +environment variable. If set, it uses subdirectories in the given +directory to create its temporary working directories. Else it uses +.I /var/tmp +as default value for that purpose. The given directory should be on a +filesystem which allows the execution of files stored there, i.e. +should not be mounted with the +.B noexec +mount option. + +If +.B SOURCE_DATE_EPOCH +is set, +.B mkinitramfs +attempts to generate a reproducible initramfs image. + +.SH FILES +.TP +.I /etc/initramfs-tools/initramfs.conf +The default configuration file for the script. See +.BR initramfs.conf (5) +for a description of the available configuration parameter. + +.TP +.I /etc/initramfs-tools/modules +Specified modules will be put in the generated image and loaded when the system boots. The format - one per line - is identical to that of +.I /etc/modules, +which is described in +.BR modules (5). + +.TP +.I /etc/initramfs-tools/conf.d +The conf.d directory allows one to hardcode bootargs at initramfs build time +via config snippets. This allows one to set ROOT or RESUME. +This is especially useful for bootloaders, which do not pass an root bootarg. + +.TP +.I /etc/initramfs-tools/DSDT.aml +If this file exists, it will be appended to the initramfs in a way that causes +it to be loaded by ACPI. + +.SH EXAMPLES + +Create an initramfs for current running kernel: + +.PP +.B mkinitramfs -o ~/tmp/initramfs-$(uname -r) + +Create an initramfs for specific kernel and keep builddirs: + +.PP +.B mkinitramfs -k -o ~/tmp/initramfs-2.6.21-686 2.6.21-686 + +Debug initramfs creation (check out written logfile) +.PP +.B sh -x mkinitramfs -o ~/tmp/initramfs-$(uname -r) 2> ~/tmp/log + +.SH AUTHOR +The initramfs-tools are written by Maximilian Attems <maks@debian.org>, +Jeff Bailey <jbailey@raspberryginger.com> and numerous others. + +.SH SEE ALSO +.BR +.IR initramfs.conf (5), +.IR initramfs-tools (7), +.IR update-initramfs (8), +.IR lsinitramfs (8), +.IR unmkinitramfs (8). |