Problem: lost/zeroed boot partition (I've experienced this ~5 times so far)

Solution ("#" at start of command = running as root):
1.
Startup Arch Linux liveboot
2.
Connect to wifi by running "man iwctl | cat; iwctl" and "iwctl> station wlan0 connect [ssid]" and whatever)
3.
# curl -L https://web.archive.org/web/20241122165154if_/https://www.cgsecurity.org/testdisk-7.3-WIP.linux26-x86_64.tar.bz2 | tar -xj
4.
cd into that folder with the "testdisk_static" file
5.
# ./testdisk_static /dev/sda
6.
Go through testdisk's interactive thing, it'll restore the non-boot partition but not the boot partition
7.
Maybe reboot so the previously missing /dev/sda1 will show up.
8
Boot partition maybe has to be /dev/sda1 and not /dev/sda2, so move /dev/sda1 to /dev/sda2
9.
# sfdisk --dump /dev/sda > sda.bkp
10.
# cp sda.bkp sda.bkp.bak
11.
# vim sda.bkp
12.
Change "/dev/sda1" to "/dev/sda2", save the text file
13.
# sfdisk /dev/sda < sda.bkp
14.
# fdisk /dev/sda
15.
Interactive thing, "n" for new partition should be at the start of sda, like sector 2048 to 618,495.
16
"t" to change type of sda1 to EFI which is number 1 - not sure if this step is necessary. "w" to write partition.
17.
For the new/EFI partition you just created:
# mkfs.fat -F 32 /dev/sda1"
18.
# note: https://superuser.com/questions/1234860
19.
Mount HDD root partition:
# mkdir /mnt/a
# mount /dev/sda2 /mnt/a"
20.
Mount live media stuff to HDD root mount:
# mount -o bind /dev /mnt/a/dev
# mount -o bind /proc /mnt/a/proc
# mount -o bind /sys /mnt/a/sys
21.
# mount /dev/sda1 /mnt/a/boot/efi
22.
# SHELL=/bin/bash
# chroot /mnt/a
23.
# /sbin/grub-install
24.
Exit chrooted environment where /mnt/a was / and /mnt/a/boot/efi was /boot/efi:
# exit
25.
# shutdown now
26.
Remove liveboot medium, power on computer.
27.
It should be fixed and boot and everything: worked every time for me.