#!/usr/bin/env zsh
set -x

# Problems: cgpt has a fixed set of partition Types by name or hex, not UUID.

# Partition table for root and boot
parted_type="gpt"
gpt_idbloader=(64 8063)
gpt_uboot=(16384 24575)
gpt_trust=(24576 32767)
gpt_boot=(32768 229376)  # start and end values for partitioning the `boot` partition.
gpt_root=(262144)        # currently libdevuansdk chooses this as a startpoint, and maxes out remaining
bootfs="vfat"
rootfs="ext4"

# Define max sizes and offsets
IDBLOADER_OFFSET=$((4*1024*1024/512))    #      4MiB    8192
UBOOT_OFFSET=$((8*1024*1024/512))        #      8MiB   16384
TRUST_OFFSET=$((12*1024*1024/512))       #     12MiB   24575
BOOT_OFFSET=$((16*1024*1024/512))        #     16MiB   32768
ROOT_OFFSET=$((128*1024*1024/512))       #    128MiB  262144

gpt_idbloader=(64 $((IDBLOADER_OFFSET-1)))
gpt_uboot=($((IDBLOADER_OFFSET)) $((TRUST_OFFSET-1)))
gpt_trust=($((TRUST_OFFSET)) $((BOOT_OFFSET-1)))
gpt_boot=($((BOOT_OFFSET)) $((ROOT_OFFSET-1)))
gpt_root=($((ROOT_OFFSET)))  

size=4098
image_name=decode-cgpt
workdir=${PWD}

dd if=/dev/zero \
	of=$workdir/${image_name}.img \
	bs=1M \
	count=$size

parted $workdir/${image_name}.img --script -- mklabel gpt 
cgpt create -z $workdir/${image_name}.img 
cgpt create    $workdir/${image_name}.img 
cgpt repair    $workdir/${image_name}.img
cgpt show      $workdir/${image_name}.img

# Create partition using start and end values for partitioning the `idbloader` partition.
# -i 3 -l idbloader -b 64 -s 8063 -t basicdata 
#
# -i Specify partition number
# -l says label in the instructions but actually changes the name
# -b First block (a.k.a. start of partition)
# -s Size (in blocks)
# -t Partition Type GUID - see below after code
cgpt add \
	-i 3 \
	-l idbloader \
        -b ${gpt_idbloader[1]} \
	-s ${gpt_idbloader[2]} \
	-t data \
        $workdir/${image_name}.img
 
# Create partition using start and end values for partitioning the `uboot` partition.
# -i 4 -l uboot	-b 16384 -s 24575 -t basicdata 
cgpt add \
	-i 4 \
	-l uboot \
        -b ${gpt_uboot[1]} \
	-s ${gpt_uboot[2]} \
	-t data \
        $workdir/${image_name}.img
 
## Create partition using start and end values for partitioning the `trust` partition.
# -i 5 -l trust -b 24576 -s 32767 -t basicdata
cgpt add \
	-i 5 \
	-l trust \
        -b ${gpt_trust[1]} \
	-s ${gpt_trust[2]} \
	-t data \
        $workdir/${image_name}.img
 
# Create partition using start and end values for partitioning the `boot` partition.
# -i 1 -l kernel -b 32768 -s 229376 -t kernel -S 1 -T 5 -P 10
cgpt add \
	-i 1 \
	-l boot \
        -b ${gpt_boot[1]} \
	-s ${gpt_boot[2]} \
	-t kernel \
        -S 1 -T 5 -P 10 \
        $workdir/${image_name}.img
 
# Create partion using just the start value, and maxes out remaining, 
# -i 2 -l root -b 262144 -s 8130527 -t data
cgpt add \
	-i 2 \
	-l root \
        -b ${gpt_root[1]} \
	-s $(expr $(cgpt show $workdir/${image_name}.img | \
	awk '/Sec GPT table/ {print $1}') - ${gpt_root[1]}) \
	-t  data \
        $workdir/${image_name}.img

sgdisk --print $workdir/${image_name}.img

# cgpt add -h
# The partition type may also be given as one of these aliases:
#    firmware    ChromeOS firmware		FFFF
#    kernel      ChromeOS kernel		7F00	ChromeOS kernel
#    rootfs      ChromeOS rootfs		7F01	ChromeOS root
#    data        Linux data			8300	Linux filesystem
#    basicdata   Basic data			0700	Microsoft basic data
#    reserved    ChromeOS reserved		7F02	ChrOS reserved
#    efi         EFI System Partition		EF00	EFI system partition
#    unused      Unused (nonexistent) partition NOT AVAILABLE


# sgdisk -L
#
# 0700 Microsoft basic data                0c01 Microsoft reserved
# 2700 Windows RE                          3000 ONIE boot
# 3001 ONIE config                         3900 Plan 9
# 4100 PowerPC PReP boot                   4200 Windows LDM data
# 4201 Windows LDM metadata                4202 Windows Storage Spaces
# 7501 IBM GPFS                            7f00 ChromeOS kernel
# 7f01 ChromeOS root                       7f02 ChromeOS reserved
# 8200 Linux swap                          8300 Linux filesystem
# 8301 Linux reserved                      8302 Linux /home
# 8303 Linux x86 root (/)                  8304 Linux x86-64 root (/)
# 8305 Linux ARM64 root (/)                8306 Linux /srv
# 8307 Linux ARM32 root (/)                8308 Linux dm-crypt
# 8309 Linux LUKS                          830a Linux IA-64 root (/)
# 830b Linux x86 root verity               830c Linux x86-64 root verity
# 830d Linux ARM32 root verity             830e Linux ARM64 root verity
# 830f Linux IA-64 root verity             8310 Linux /var
# 8311 Linux /var/tmp                      8400 Intel Rapid Start
# 8500 Container Linux /usr                8501 Container Linux resizable rootfs
# 8502 Container Linux /OEM customization  8503 Container Linux root on RAID
# 8e00 Linux LVM                           a000 Android bootloader
# a001 Android bootloader 2                a002 Android boot 1
# a003 Android recovery 1                  a004 Android misc
# a005 Android metadata                    a006 Android system 1
# a007 Android cache                       a008 Android data
# a009 Android persistent                  a00a Android factory
# a00b Android fastboot/tertiary           a00c Android OEM
# a00d Android vendor                      a00e Android config
# a00f Android factory (alt)               a010 Android meta
# a011 Android EXT                         a012 Android SBL1
# a013 Android SBL2                        a014 Android SBL3
# a015 Android APPSBL                      a016 Android QSEE/tz
# a017 Android QHEE/hyp                    a018 Android RPM
# a019 Android WDOG debug/sdi              a01a Android DDR
# a01b Android CDT                         a01c Android RAM dump
# a01d Android SEC                         a01e Android PMIC
# a01f Android misc 1                      a020 Android misc 2
# a021 Android device info                 a022 Android APDP
# a023 Android MSADP                       a024 Android DPO
# a025 Android recovery 2                  a026 Android persist
# a027 Android modem ST1                   a028 Android modem ST2
# a029 Android FSC                         a02a Android FSG 1
# a02b Android FSG 2                       a02c Android SSD
# a02d Android keystore                    a02e Android encrypt
# a02f Android EKSST                       a030 Android RCT
# a031 Android spare1                      a032 Android spare2
# a033 Android spare3                      a034 Android spare4
# a035 Android raw resources               a036 Android boot 2
# a037 Android FOTA                        a038 Android system 2
# a039 Android cache                       a03a Android user data
# a03b LG (Android) advanced flasher       a03c Android PG1FS
# a03d Android PG2FS                       a03e Android board info
# a03f Android MFG                         a040 Android limits
# a200 Atari TOS basic data                a500 FreeBSD disklabel
# a501 FreeBSD boot                        a502 FreeBSD swap
# a503 FreeBSD UFS                         a504 FreeBSD ZFS
# a505 FreeBSD Vinum/RAID                  a580 Midnight BSD data
# a581 Midnight BSD boot                   a582 Midnight BSD swap
# a583 Midnight BSD UFS                    a584 Midnight BSD ZFS
# a585 Midnight BSD Vinum                  a600 OpenBSD disklabel
# a800 Apple UFS                           a901 NetBSD swap
# a902 NetBSD FFS                          a903 NetBSD LFS
# a904 NetBSD concatenated                 a905 NetBSD encrypted
# a906 NetBSD RAID                         ab00 Recovery HD
# af00 Apple HFS/HFS+                      af01 Apple RAID
# af02 Apple RAID offline                  af03 Apple label
# af04 AppleTV recovery                    af05 Apple Core Storage
# af06 Apple SoftRAID Status               af07 Apple SoftRAID Scratch
# af08 Apple SoftRAID Volume               af09 Apple SoftRAID Cache
# af0a Apple APFS                          b300 QNX6 Power-Safe
# bc00 Acronis Secure Zone                 be00 Solaris boot
# bf00 Solaris root                        bf01 Solaris /usr & Mac ZFS
# bf02 Solaris swap                        bf03 Solaris backup
# bf04 Solaris /var                        bf05 Solaris /home
# bf06 Solaris alternate sector            bf07 Solaris Reserved 1
# bf08 Solaris Reserved 2                  bf09 Solaris Reserved 3
# bf0a Solaris Reserved 4                  bf0b Solaris Reserved 5
# c001 HP-UX data                          c002 HP-UX service
# e100 ONIE boot                           e101 ONIE config
# e900 Veracrypt data                      ea00 Freedesktop $BOOT
# eb00 Haiku BFS                           ed00 Sony system partition
# ed01 Lenovo system partition             ef00 EFI system partition
# ef01 MBR partition scheme                ef02 BIOS boot partition
# f800 Ceph OSD                            f801 Ceph dm-crypt OSD
# f802 Ceph journal                        f803 Ceph dm-crypt journal
# f804 Ceph disk in creation               f805 Ceph dm-crypt disk in creation
# f806 Ceph block                          f807 Ceph block DB
# f808 Ceph block write-ahead log          f809 Ceph lockbox for dm-crypt keys
# f80a Ceph multipath OSD                  f80b Ceph multipath journal
# f80c Ceph multipath block 1              f80d Ceph multipath block 2
# f80e Ceph multipath block DB             f80f Ceph multipath block write-ahead l
# f810 Ceph dm-crypt block                 f811 Ceph dm-crypt block DB
# f812 Ceph dm-crypt block write-ahead lo  f813 Ceph dm-crypt LUKS journal
# f814 Ceph dm-crypt LUKS block            f815 Ceph dm-crypt LUKS block DB
# f816 Ceph dm-crypt LUKS block write-ahe  f817 Ceph dm-crypt LUKS OSD
# fb00 VMWare VMFS                         fb01 VMWare reserved
# fc00 VMWare kcore crash protection       fd00 Linux RAID