Initial commit

.gitignore

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+artifacts/
+stage/
+mnt/

LICENSE

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+MIT License
+
+Copyright (c) 2022 Kouji Matsui
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# Setup latest Debian mipsel on qemu malta
+
+Reference:
+  https://gist.github.com/extremecoders-re/3ddddce9416fc8b293198cd13891b68c
+
+----
+
+## How to use it
+
+Perhaps the script needs to be modified slightly to match the latest image. I used [Latest Debian 11 (bullseye) from "debian-11.3.0-mipsel-netinst.iso"](http://cdimage.debian.org/cdimage/release/current/mipsel/iso-cd/debian-11.3.0-mipsel-netinst.iso) as a base.
+
+1. Run `build.sh`, it will download cd image from debian server, build qcow virtual hard disk image and run debian installer.
+
+![installing](Images/installing.png)
+
+2. Rebooted in finally installation step, choose `Execute shell` from menu and do `poweroff` command, then will exit qemu.
+
+3. Ready to use. Run `run.sh` then raise up debian 11 mipsel on qemu!
+
+![run](Images/run.png)
+
+### Enabled ssh forwarding on port 2222
+
+```bash
+ssh localhost -p 2222
+```
+
+Have fun!
+
+----
+
+## Background
+
+It's completely off-topic, and probably a strange nerd story :)
+
+I am developing [a .NET library for video capture](https://github.com/kekyo/FlashCap).
+I thought this library should be tested in a variety of environments in order to be truly multi-platform.
+So, I was looking for a somewhat minor environment in which .NET (actually mono) would work,
+and ["Imagination Creator Ci20" was found.](https://uk.rs-online.com/web/p/single-board-computers/1253305)
+
+The Ci20 is a MIPS 32-bit architecture that is still barely available and can operate as a USB host.
+It seemed feasible to perform video capture via V4L2, supporting USB Video Class.
+So, we quickly obtained this board and found that only supports Debian 8 (jessie) and
+Moreover, it seemed to have been removed from the supported list as a beta release.
+
+After [some information and trial and error](https://gist.github.com/kekyo/1d851907bf5b59ddb204448de3b18383),
+I succeeded in applying the latest binary packages for Debian 8.
+Apparently there is still an eMMC access bug in the kernel, which causes the system to stop
+with UBIFS-derived panic when I/O is under high load.
+Also, I need a relatively new version of Clang, but Debian 8 only has an older version,
+and If I try to build it on my own, I get the above panic and am out of luck.
+
+I wish I could fix this kernel fundamentally, but unfortunately, I do not have that much knowledge.
+So I have decided to take other steps.
+
+I realized that building the code on a modern Debian 11 using qemu's mipsel emulation would work fine,
+so I created this script by trial and error from my sources.
+
+----
+
+## License
+
+MIT

build.sh

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+#!/bin/bash
+
+# https://gist.github.com/extremecoders-re/3ddddce9416fc8b293198cd13891b68c
+
+#--------------------------------------------
+# Require these packages.
+echo "sudo apt install qemu qemu-system-mips qemu-utils"
+sudo apt install qemu qemu-system-mips qemu-utils
+
+#--------------------------------------------
+# Enable qcow mounter.
+sudo modprobe nbd max_part=8
+
+#--------------------------------------------
+# Create staging directories.
+if [ ! -d artifacts ]; then
+  mkdir artifacts
+fi
+if [ ! -d stage ]; then
+  mkdir stage
+fi
+if [ ! -d mnt ]; then
+  mkdir mnt
+fi
+
+#--------------------------------------------
+# Download debian image.
+cd artifacts
+
+# Choose mirror server and latest image file.
+if [ ! -f debian-*.iso ]; then
+  wget http://cdimage.debian.org/cdimage/release/current/mipsel/iso-cd/debian-11.3.0-mipsel-netinst.iso
+fi
+
+cd ..
+
+#--------------------------------------------
+# Extract installer kernel image and root filesystem image.
+
+sudo mount -r -t iso9660 artifacts/debian-*.iso mnt/
+cp mnt/install/malta/netboot/vmlinuz* artifacts/vmlinuz-netinst
+cp mnt/install/malta/netboot/initrd* artifacts/initrd-netinst.gz
+sudo umount mnt/
+
+#--------------------------------------------
+# Create hard disk image.
+
+cd stage
+qemu-img create -f qcow2 hda.qcow 16G
+
+#--------------------------------------------
+# Install debian.
+
+qemu-system-mipsel \
+  -M malta \
+  -m 1024 \
+  -cdrom ../artifacts/debian-*.iso \
+  -hda hda.qcow \
+  -kernel ../artifacts/vmlinuz-netinst \
+  -initrd ../artifacts/initrd-netinst.gz \
+  -boot d \
+  -nographic \
+  -append "root=/dev/sda1 nokaslr"
+
+cd ..
+
+#--------------------------------------------
+# Extract bootable kernel image and root filesystem image.
+
+sudo qemu-nbd --connect=/dev/nbd0 `pwd`/stage/hda.qcow
+sudo mount -r /dev/nbd0p1 `pwd`/mnt
+cp mnt/boot/vmlinuz* stage/vmlinuz
+cp mnt/boot/initrd* stage/initrd.img
+sudo umount /dev/nbd0p1
+sudo qemu-nbd --disconnect /dev/nbd0
+
+#--------------------------------------------
+
+echo "Done."

run.sh

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+#!/bin/bash
+
+#--------------------------------------------
+# Run debian on qemu.
+
+cd stage
+
+qemu-system-mipsel \
+  -M malta \
+  -m 2048 \
+  -hda hda.qcow \
+  -kernel vmlinuz \
+  -initrd initrd.img \
+  -append "root=/dev/sda1 console=ttyS0 nokaslr" \
+  -nographic \
+  -net user,hostfwd=tcp:127.0.0.1:2222-:22 \
+  -net nic,model=e1000-82545em
+
+cd ..