initramfs打包模块进initrd.img

查看模块

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modprobe --show-depends nbd

nbd模块名称

模块存在会显示路径

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insmod /lib/modules/5.15.0-76-generic/kernel/drivers/block/nbd.ko

增加模块

修改/etc/initramfs-tools/modules

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# List of modules that you want to include in your initramfs.
# They will be loaded at boot time in the order below.
#
# Syntax:  module_name [args ...]
#
# You must run update-initramfs(8) to effect this change.
#
# Examples:
#
# raid1
# sd_mod
nbd
net # 网络模块
# squashfs
# ahci
# libahci
# usb-storage
# nls_iso8859-1
# virtio_scsi
# sdhci
# sdhci-pci
# sdhci-acpi
# mmc-block
# hv_storvsc
# hv_vmbus

制作

然后使用mkinitramfs制作initrd.img

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mkinitramfs -o initrd.img

模块位置

/lib/modules/

注意

需要注意/etc/initramfs-tools/initramfs.conf中的配置

MODULES=most会打包大部分文件系统和所有硬盘驱动。

MODULES=dep试着猜测要加载哪些模块。（有可能不会打包modules中配置的模块，很坑的；国产系统的默认配置）。

MODULES=netboot添加基本模块，网络模块，但跳过块设备。（这个模式打包的initrd一般用来做网络启动）

MODULES=list只会打包/etc/initramfs-tools/modules中的写的模块。

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#
# initramfs.conf
# Configuration file for mkinitramfs(8). See initramfs.conf(5).
#
# Note that configuration options from this file can be overridden
# by config files in the /etc/initramfs-tools/conf.d directory.

#
# MODULES: [ most | netboot | dep | list ]
#
# most - Add most filesystem and all harddrive drivers.
#
# dep - Try and guess which modules to load.
#
# netboot - Add the base modules, network modules, but skip block devices.
#
# list - Only include modules from the 'additional modules' list
#

MODULES=most

#
# BUSYBOX: [ y | n | auto ]
#
# Use busybox shell and utilities.  If set to n, klibc utilities will be used.
# If set to auto (or unset), busybox will be used if installed and klibc will
# be used otherwise.
#

BUSYBOX=auto

#
# COMPCACHE_SIZE: [ "x K" | "x M" | "x G" | "x %" ]
#
# Amount of RAM to use for RAM-based compressed swap space.
#
# An empty value - compcache isn't used, or added to the initramfs at all.
# An integer and K (e.g. 65536 K) - use a number of kilobytes.
# An integer and M (e.g. 256 M) - use a number of megabytes.
# An integer and G (e.g. 1 G) - use a number of gigabytes.
# An integer and % (e.g. 50 %) - use a percentage of the amount of RAM.
#
# You can optionally install the compcache package to configure this setting
# via debconf and have userspace scripts to load and unload compcache.
#

COMPCACHE_SIZE=""

#
# COMPRESS: [ gzip | bzip2 | lz4 | lzma | lzop | xz ]
#

COMPRESS=lz4

#
# NFS Section of the config.
#

#
# DEVICE: ...
#
# Specify a specific network interface, like eth0
# Overridden by optional ip= or BOOTIF= bootarg
#

DEVICE=

#
# NFSROOT: [ auto | HOST:MOUNT ]
#

NFSROOT=auto

#
# RUNSIZE: ...
#
# The size of the /run tmpfs mount point, like 256M or 10%
# Overridden by optional initramfs.runsize= bootarg
#

RUNSIZE=10%