From 74f2aa62474c670fbbd1d1e824c692cd43056f33 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Sat, 6 May 2023 23:03:51 +0100
Subject: [PATCH] initramfs-peek: an initramfs image with a shell, for
debugging
---
pkgs/default.nix | 1 +
pkgs/initramfs-peek/default.nix | 37 +++++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+)
create mode 100644 pkgs/initramfs-peek/default.nix
diff --git a/pkgs/default.nix b/pkgs/default.nix
index ad3855e71..7e4feb45f 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -45,6 +45,7 @@
openwrt = callPackage ./openwrt {};
+ initramfs-peek = callPackage ./initramfs-peek {};
min-copy-closure = callPackage ./min-copy-closure {};
hi = callPackage ./hi {};
}
diff --git a/pkgs/initramfs-peek/default.nix b/pkgs/initramfs-peek/default.nix
new file mode 100644
index 000000000..39067cb9b
--- /dev/null
+++ b/pkgs/initramfs-peek/default.nix
@@ -0,0 +1,37 @@
+{
+ busybox
+, pkgsBuildBuild
+, runCommand
+, cpio
+, writeReferencesToFile
+, writeScript
+} :
+let
+ inherit (pkgsBuildBuild) gen_init_cpio;
+ script = writeScript "init" ''
+ #!/bin/sh
+ exec >/dev/console
+ echo Running in initramfs
+ PATH=${busybox}/bin:$PATH
+ export PATH
+ mount -t proc none /proc
+ mount -t sysfs none /sys
+ ${busybox}/bin/sh
+ '';
+ refs = writeReferencesToFile busybox;
+in runCommand "initramfs.cpio" { } ''
+ cat << SPECIALS | ${gen_init_cpio}/bin/gen_init_cpio /dev/stdin > out
+ dir /proc 0755 0 0
+ dir /sys 0755 0 0
+ dir /dev 0755 0 0
+ nod /dev/console 0600 0 0 c 5 1
+ nod /dev/mtdblock0 0600 0 0 b 31 0
+ dir /nix 0755 0 0
+ dir /nix/store 0755 0 0
+ dir /bin 0755 0 0
+ file /bin/sh ${busybox}/bin/sh 0755 0 0
+ file /init ${script} 0755 0 0
+ SPECIALS
+ find $(cat ${refs}) | ${pkgsBuildBuild.cpio}/bin/cpio -H newc -o -A -v -O out
+ cp out $out
+''