From d3c0d6890a7770a94b6463da39f5ba613b02cb3a Mon Sep 17 00:00:00 2001 From: Ralph Ronnquist Date: Sat, 9 Mar 2024 00:27:45 +1100 Subject: [PATCH] adding some basic documentation --- README.adoc | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 README.adoc diff --git a/README.adoc b/README.adoc new file mode 100644 index 0000000..f0e6f44 --- /dev/null +++ b/README.adoc @@ -0,0 +1,49 @@ += rescue-boot + +This project holds scripts that prepares a "rescue" boot image file +with a Devuan ceres minbase filesystem. + +* +./minbase-strap.sh+ prepares boot-ceres-$ARCH.img + + - +./minbase-strap-bios.sh+ include fragment preparing bios boot equipment + + - +./minbase-strap-uefi.sh+ include fragment preparing uefi boot equipment + + - +./minbase-strap-mkimg.sh+ include fragment packaging into disk file + +* +./run.sh boot-ceres-$ARCH.img+ boots it up in a virtual machine. + +== About the boot image preparation + +The rescue boot image is a full disk image with two partitions. The +first is a FAT partition that contains a linux kernel and initrd for +the kernel and boot equipments using syslinux for both legacy bios and +UEFI bios boot. + +The initrd.gz file is quite large makign the partition somewhat larger +than 100M and this makes it less ameniable as boot image for a hybrid +ISO (which has a 32M limit). + +The preparation populates a root filesystem in the FS directory by +using debootstrap followed by certain "Captain's Picks" to include +partcular choice software. + +The scripting asks firstly for a kernel choice and then an init script +choice to optionally replace the "standard" initrd init script with +some rescue variant. + +== About the virtual machine setup + +The run.sh script starts a QEMU system emulator for the boot image +given on the command line. E.g., + + $ ./run.sh boot-ceres-amd64.img + +With environment setting EFI=yes, the emulation uses UEFI boot. E.g. + + $ EFI=yes ./run.sh boot-ceres-amd64.img + +The script assumes the host has a "vde2" setup with a "vde-switch" +using control directory "/run/vde.ctl". Any alternatie network setup +needs script hands-on to change the "NET=.." variable. + -- 2.39.2