notes: initialize contents

content/notes/trace-execve-and-execveat.mdx

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+---
+title: Trace execve and execveat
+date: 2023-12-17 20:00:08+08:00
+tags: [ptrace, linux]
+---
+
+import AsciinemaPlayer from "../../src/components/mdx/asciinema-player.tsx"
+
+Use old school `strace`:
+
+```bash
+strace -Y -f -qqq -s99999 -e trace=execve,execveat <command>
+```
+
+Or an alternative I wrote in Rust (prettier output): https://github.com/kxxt/tracexec
+
+```bash
+tracexec log --show-cmdline -- <command>
+```
+
+<AsciinemaPlayer src="https://asciinema.org/a/AWTG4iHaFPMcEGCVtqAl44YFW.cast" rows={28} cols={114}/>

content/notes/unpack-android-ota.mdx

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+---
+title: Unpack Android OTA
+date: 2023-12-17 20:15:26+08:00
+tags: [android]
+---
+
+Short answer: use https://github.com/AndroidDumps/dumpyara , which will dump almost everything of interest.
+
+To unpack individual images: use [`payload-dumper-go`](https://github.com/ssut/payload-dumper-go), which is available in ArchLinuxCN repo.
+
+If you REALLY want to do it by hand, here is the way to extract individual images from `super.img`:
+
+If `super.img` is a sparse image, then we need to unsparse it first.
+
+```bash
+$ file imgs/CN/super.img  
+imgs/CN/super.img: Android sparse image, version: 1.0, Total of 2228224 4096-byte output blocks in 141 input chunk  
+s.
+```
+
+Use `simg2img` from Arch Linux `extra/android-tools` package to unsparse it.
+
+```bash
+simg2img super.img super.img.unsparsed
+```
+
+Then we can unpack it using `lpunpack` from Arch Linux `extra/android-tools` package.
+
+```bash
+mkdir dump
+lpunpack super.img.unsparsed dump
+```