PicoMitchell/get_compatible_macos_versions-asls.sh

## get_compatible_macos_versions-asls.sh
#!/bin/bash

#
# Created by Pico Mitchell (of Random Applications) on 1/5/23
#
# https://gist.github.com/PicoMitchell/877b645b113c9a5db95248ed1d496243#file-get_compatible_macos_versions-asls-sh
#
# MIT License
#
# Copyright (c) 2023 Pico Mitchell (Random Applications)
#
# 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.
#

readonly SCRIPT_VERSION='2023.4.16-1'

PATH='/usr/bin:/bin:/usr/sbin:/sbin'

current_macos_version="$(sw_vers -productVersion)"

echo "Running \"$(basename "${BASH_SOURCE[0]}")\" version ${SCRIPT_VERSION} on macOS ${current_macos_version} $(sw_vers -buildVersion)..."

mac_board_id=''
mac_device_id=''

mac_is_apple_silicon="$([[ "$(sysctl -in hw.optional.arm64)" == '1' ]] && echo 'true' || echo 'false')"

if [[ " $(sysctl -in machdep.cpu.features) " == *' VMM '* || "$(sysctl -in kern.hv_vmm_present)" == '1' ]]; then
	# "machdep.cpu.features" is always EMPTY on Apple Silicon (whether or not it's a VM) so it cannot be used to check for the "VMM" feature flag when the system is a VM,
	# but I examined the full "sysctl -a" output when running a VM on Apple Silicon and found that "kern.hv_vmm_present" is set to "1" when running a VM and "0" when not.
	# Through testing, I found the "kern.hv_vmm_present" key is also the present on Intel Macs starting with macOS 11 Big Sur and gets properly set to "1"
	# on Intel VMs, but still check for either since "kern.hv_vmm_present" is not available on every version of macOS that this script may be run on.

	mac_device_id="$($mac_is_apple_silicon && echo 'VMA2MACOSAP' || echo 'VMM-x86_64')" # These are the Device IDs listed in the "Apple Software Lookup Service" JSON for Apple Silicon and Intel VMs.
else
	if ! $mac_is_apple_silicon; then # Only Intel Macs have a Board ID. T2 Macs (which are Intel) will have both a Board ID and Device ID while Apple Silicon Macs only have a Device ID.
		mac_board_id="$(/usr/libexec/PlistBuddy -c 'Print 0:board-id' /dev/stdin <<< "$(ioreg -arc IOPlatformExpertDevice -k board-id -d 1)" 2> /dev/null | tr -d '[:cntrl:]')" # Remove control characters because this decoded value could end with a NUL char.

		if [[ "${mac_board_id}" != 'Mac-'* ]]; then
			>&2 echo 'ERROR: Failed to retrieve Board ID for Intel Mac.'
			exit 2
		fi
	fi

	if [[ -n "$(ioreg -rc AppleSEPManager)" ]]; then # The Device ID only exists for T2 and Apple Silicon Macs, both of which have a Secure Enclave (SEP).
		if $mac_is_apple_silicon; then # For Apple Silicon Macs, the Device ID is the first element of the "compatible" array in "ioreg -rc IOPlatformExpertDevice -d 1"
			# Annoyingly, the "compatible" array is easier to get elements out of from the plain text output rather than the plist output since the value is not actually a proper plist array.
			# NOTE: This "compatible" array will also exist on Intel Macs, but it will only contain the Model ID which was already retrieved above.
			mac_device_id="$(ioreg -rc IOPlatformExpertDevice -k compatible -d 1 | awk -F '"' '($2 == "compatible") { print $4; exit }')"
		else
			mac_device_id="$(/usr/libexec/remotectl get-property localbridge HWModel 2> /dev/null)" # For T2 Macs, this is the T2 chip Device ID.
		fi

		if [[ "${mac_device_id}" != *'AP' ]]; then
			>&2 echo 'ERROR: Failed to retrieve Device ID for T2 or Apple Silicon Mac.'
			exit 3
		fi
	fi
fi

asls_url='https://gdmf.apple.com/v2/pmv'
# About "Apple Software Lookup Service" (from https://support.apple.com/guide/deployment/use-mdm-to-deploy-software-updates-depafd2fad80/1/web/1.0#dep0b094c8d3 & https://developer.apple.com/business/documentation/MDM-Protocol-Reference.pdf):
# Use the service at https://gdmf.apple.com/v2/pmv to obtain a list of available updates.
# The JSON response contains two lists of available software releases. The "AssetSets" list contains all the releases available for MDMs to push to their supervised devices.
# The other list, "PublicAssetSets" contains the latest releases available to the general public (non-supervised devices) if they try to upgrade. The "PublicAssetSets" is a subset of the "AssetSets" list.
# Each element in the list contains the product version number of the OS, the posting date, the expiration date, and a list of supported devices for that release.

if ! asls_json="$(curl -m 5 -sfL "${asls_url}")" || [[ "${asls_json}" != *'"PublicAssetSets"'* ]]; then
	>&2 echo 'ERROR: Failed to download Apple Software Lookup Service JSON.'
	exit 4
fi

compatible_supported_macos_versions="$(osascript -l JavaScript -e '
"use strict"
function run(argv) {
	const macBoardID = argv[0], macDeviceID = argv[1], supportedVersion = []
	JSON.parse(argv[2]).PublicAssetSets.macOS.forEach(thisVersionDict => {
		const thisVersionSupportedDevices = thisVersionDict.SupportedDevices
		if ((macBoardID && thisVersionSupportedDevices.includes(macBoardID)) || (macDeviceID && thisVersionSupportedDevices.includes(macDeviceID)))
			supportedVersion.push(thisVersionDict.ProductVersion)
	})
	return supportedVersion.sort((thisVersion, thatVersion) => ObjC.wrap(thatVersion).compareOptions(thisVersion, $.NSNumericSearch)).join("\n")
}
' -- "${mac_board_id}" "${mac_device_id}" "${asls_json}" 2> /dev/null)"

echo -e "\nLatest Compatible macOS Version: $(echo "${compatible_supported_macos_versions}" | head -1)"

current_macos_major_version="${current_macos_version%%.*}"
echo -e "\nLatest Version of macOS ${current_macos_major_version} (Running Version): $(echo "${compatible_supported_macos_versions}" | grep -m 1 "^${current_macos_major_version}")"

echo -e "\nAll Compatible Supported macOS Versions:\n${compatible_supported_macos_versions}"

## get_compatible_macos_versions-sucatalog.sh
#!/bin/bash

#
# Created by Pico Mitchell (of Random Applications) on 4/5/22
#
# https://gist.github.com/PicoMitchell/877b645b113c9a5db95248ed1d496243#file-get_compatible_macos_versions-sucatalog-sh
#
# MIT License
#
# Copyright (c) 2022 Pico Mitchell (Random Applications)
#
# 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.
#

readonly SCRIPT_VERSION='2023.4.16-1'

PATH='/usr/bin:/bin:/usr/sbin:/sbin'

current_macos_version="$(sw_vers -productVersion)"

echo "Running \"$(basename "${BASH_SOURCE[0]}")\" version ${SCRIPT_VERSION} on macOS ${current_macos_version} $(sw_vers -buildVersion)..."

mac_model_id="$(sysctl -n hw.model)"
mac_board_id=''
mac_device_id=''

mac_is_virtual_machine="$([[ " $(sysctl -in machdep.cpu.features) " == *' VMM '* || "$(sysctl -in kern.hv_vmm_present)" == '1' ]] && echo 'true' || echo 'false')"
# "machdep.cpu.features" is always EMPTY on Apple Silicon (whether or not it's a VM) so it cannot be used to check for the "VMM" feature flag when the system is a VM,
# but I examined the full "sysctl -a" output when running a VM on Apple Silicon and found that "kern.hv_vmm_present" is set to "1" when running a VM and "0" when not.
# Through testing, I found the "kern.hv_vmm_present" key is also the present on Intel Macs starting with macOS 11 Big Sur and gets properly set to "1"
# on Intel VMs, but still check for either since "kern.hv_vmm_present" is not available on every version of macOS that this script may be run on.

if ! $mac_is_virtual_machine; then # VMs will just show all versions of macOS as compatible.
	if [[ "${mac_model_id}" != *'Mac'* ]]; then
		>&2 echo 'ERROR: Failed to retrieve Model ID.'
		exit 1
	fi

	mac_is_apple_silicon="$([[ "$(sysctl -in hw.optional.arm64)" == '1' ]] && echo 'true' || echo 'false')"

	if ! $mac_is_apple_silicon; then # Only Intel Macs have a Board ID. T2 Macs (which are Intel) will have both a Board ID and Device ID while Apple Silicon Macs only have a Device ID.
		mac_board_id="$(/usr/libexec/PlistBuddy -c 'Print 0:board-id' /dev/stdin <<< "$(ioreg -arc IOPlatformExpertDevice -k board-id -d 1)" 2> /dev/null | tr -d '[:cntrl:]')" # Remove control characters because this decoded value could end with a NUL char.

		if [[ "${mac_board_id}" != 'Mac-'* ]]; then
			>&2 echo 'ERROR: Failed to retrieve Board ID for Intel Mac.'
			exit 2
		fi
	fi

	if [[ -n "$(ioreg -rc AppleSEPManager)" ]]; then # The Device ID only exists for T2 and Apple Silicon Macs, both of which have a Secure Enclave (SEP).
		if $mac_is_apple_silicon; then # For Apple Silicon Macs, the Device ID is the first element of the "compatible" array in "ioreg -rc IOPlatformExpertDevice -d 1"
			# Annoyingly, the "compatible" array is easier to get elements out of from the plain text output rather than the plist output since the value is not actually a proper plist array.
			# NOTE: This "compatible" array will also exist on Intel Macs, but it will only contain the Model ID which was already retrieved above.
			mac_device_id="$(ioreg -rc IOPlatformExpertDevice -k compatible -d 1 | awk -F '"' '($2 == "compatible") { print $4; exit }')"
		else
			mac_device_id="$(/usr/libexec/remotectl get-property localbridge HWModel 2> /dev/null)" # For T2 Macs, this is the T2 chip Device ID.
		fi

		if [[ "${mac_device_id}" != *'AP' ]]; then
			>&2 echo 'ERROR: Failed to retrieve Device ID for T2 or Apple Silicon Mac.'
			exit 3
		fi
	fi
fi

sucatalog_url='https://swscan.apple.com/content/catalogs/others/index-13-12-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz'

if ! sucatalog_plist="$(curl -m 10 -sfL --compressed "${sucatalog_url}")" || [[ "${sucatalog_plist}" != *'<plist'* ]]; then
	>&2 echo 'ERROR: Failed to download Software Update Catalog.'
	exit 4
fi

# Use Objective-C bridge of JavaScript for Automation (JXA) to get the English ".dist" file URLs since it requires semi-complex
# plist traversal which is much simpler using a JavaScript dictionary rather than multiple "PlistBuddy" commands in the shell.
IFS=$'\n' read -rd '' -a english_dist_urls < <(printf '%s\n' "${sucatalog_plist}" | osascript -l JavaScript -e '
"use strict"
const stdinFileHandle = $.NSFileHandle.fileHandleWithStandardInput
const sucatalogPlist = $.NSString.alloc.initWithDataEncoding((stdinFileHandle.respondsToSelector("readDataToEndOfFileAndReturnError:") ? stdinFileHandle.readDataToEndOfFileAndReturnError(ObjC.wrap()) : stdinFileHandle.readDataToEndOfFile), $.NSUTF8StringEncoding)
const englishDistURLs = []
Object.values(ObjC.deepUnwrap($.NSPropertyListSerialization.propertyListWithDataOptionsFormatError(ObjC.wrap(sucatalogPlist).dataUsingEncoding($.NSUTF8StringEncoding), $.NSPropertyListImmutable, null, ObjC.wrap())).Products).forEach(thisProductDict => {
	const thisProductExtendedMetaInfo = thisProductDict.ExtendedMetaInfo
	if (thisProductExtendedMetaInfo && thisProductExtendedMetaInfo.InstallAssistantPackageIdentifiers)
		englishDistURLs.push(thisProductDict.Distributions.English)
})
englishDistURLs.join("\n")
' 2> /dev/null)

if (( ${#english_dist_urls[@]} == 0 )) || [[ "${english_dist_urls[0]}" != 'https://'* ]]; then
	>&2 echo 'ERROR: Failed to retrieve Distribution XML URLs.'
	exit 5
fi

compatible_versions_output=''

for this_dist_url in "${english_dist_urls[@]}"; do
	this_dist_product_id="${this_dist_url##*/}"
	this_dist_product_id="${this_dist_product_id%%.*}"

	if ! this_dist_xml="$(curl -m 5 -sfL "${this_dist_url}")" || [[ "${this_dist_xml}" != *'<?xml'* ]]; then
		>&2 echo "ERROR: Failed to download Distribution XML for Product ID \"${this_dist_product_id}\"."
		exit 6
	fi

	# The ".dist" files have some plist-like sections, but are actually Distribution XML files so must use "xmllint" instead of "PlistBuddy".
	# https://developer.apple.com/library/archive/documentation/DeveloperTools/Reference/DistributionDefinitionRef/Chapters/Introduction.html
	this_dist_build="$(printf '%s\n' "${this_dist_xml}" | xmllint --xpath '//key[text()="BUILD"]/following-sibling::string[1]/text()' - 2> /dev/null)"
	this_dist_version="$(printf '%s\n' "${this_dist_xml}" | xmllint --xpath '//key[text()="VERSION"]/following-sibling::string[1]/text()' - 2> /dev/null)"

	if [[ -z "${this_dist_build}" || -z "${this_dist_version}" ]]; then
		>&2 echo "ERROR: Failed to retrieve macOS version or build for Product ID \"${this_dist_product_id}\"."
		exit 7
	elif [[ "${this_dist_build}" != *[[:lower:]] ]]; then # Ignore beta builds which end in lowercase letters.
		# The section of the Distribution XML containing the supported IDs is Installer JS (JavaScript) code (https://developer.apple.com/documentation/installer_js),
		# so just "grep" the JavaScript variable assignments to be able to check for the single quoted IDs within the JavaScript arrays.

		this_dist_supported_board_ids=''
		this_dist_supported_device_ids=''
		this_dist_non_supported_model_ids=''

		this_dist_is_compatible=false

		if $mac_is_virtual_machine; then
			this_dist_is_compatible=true
		elif this_dist_supported_board_ids="$(printf '%s\n' "${this_dist_xml}" | grep -F 'var supportedBoardIDs = [' 2> /dev/null)"; then
			if this_dist_supported_device_ids="$(printf '%s\n' "${this_dist_xml}" | grep -F 'var supportedDeviceIDs = [' 2> /dev/null)"; then
				# For macOS 11 Big Sur and newer, the ".dist" files contain JavaScript arrays of supported Board IDs and Device IDs

				if [[ "${this_dist_supported_board_ids}" == *"'${mac_board_id}'"* || "${this_dist_supported_device_ids}" == *"'${mac_device_id}'"* ]]; then # NOTICE: Checking for single quoted IDs like they are in the JavaScript arrays.
					this_dist_is_compatible=true
				fi
			else
				>&2 echo "ERROR: Failed to retrieve supportedDeviceIDs for Product ID \"${this_dist_product_id}\"."
				exit 8
			fi
		elif this_dist_supported_board_ids="$(printf '%s\n' "${this_dist_xml}" | grep -F 'var boardIds = [' 2> /dev/null)"; then
			if this_dist_non_supported_model_ids="$(printf '%s\n' "${this_dist_xml}" | grep -F 'var nonSupportedModels = [' 2> /dev/null)"; then
				# For macOS 10.15 Catalina and older, the ".dist" files contain JavaScript arrays of supported Board IDs and NON-supported Model IDs.

				if [[ "${this_dist_supported_board_ids}" == *"'${mac_board_id}'"* && "${this_dist_non_supported_model_ids}" != *"'${mac_model_id}'"* ]]; then # NOTICE: Checking for single quoted IDs like they are in the JavaScript arrays.
					this_dist_is_compatible=true
				fi
			else
				>&2 echo "ERROR: Failed to retrieve nonSupportedModels for Product ID \"${this_dist_product_id}\"."
				exit 9
			fi
		else
			>&2 echo "ERROR: Failed to retrieve supportedBoardIDs or boardIds for Product ID \"${this_dist_product_id}\"."
			exit 10
		fi

		if $this_dist_is_compatible; then
			compatible_versions_output+=$'\n'"${this_dist_version}"$'\t'"${this_dist_build}"$'\t'"${this_dist_product_id}"
		fi
	fi
done

if [[ -z "${compatible_versions_output}" ]]; then
	>&2 echo "ERROR: Failed to detect any compatible macOS versions for this Mac."
	exit 11
fi

sorted_compatible_versions_output="$(echo "${compatible_versions_output}" | sort -rV)"

echo -e "\nLatest Compatible macOS Version: $(echo "${sorted_compatible_versions_output}" | awk '{ print $1; exit }')"

current_macos_major_version="${current_macos_version%%.*}"
if (( current_macos_major_version == 10 )); then
	current_macos_major_version="$(echo "${current_macos_version}" | cut -d '.' -f '1,2')"
fi
echo -e "\nLatest Version of macOS ${current_macos_major_version} (Running Version): $(echo "${sorted_compatible_versions_output}" | AWK_ENV_CURRENT_MACOS_MAJOR_VERSION_REGEX="^${current_macos_major_version//./\\.}" awk '($1 ~ ENVIRON["AWK_ENV_CURRENT_MACOS_MAJOR_VERSION_REGEX"]) { print $1; exit }')"

echo -e "\nAll Compatible macOS Versions:\nVersion\tBuild\tProduct ID\n${sorted_compatible_versions_output}"
	#!/bin/bash

	#
	# Created by Pico Mitchell (of Random Applications) on 1/5/23
	#
	# https://gist.github.com/PicoMitchell/877b645b113c9a5db95248ed1d496243#file-get_compatible_macos_versions-asls-sh
	#
	# MIT License
	#
	# Copyright (c) 2023 Pico Mitchell (Random Applications)
	#
	# 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.
	#

	readonly SCRIPT_VERSION='2023.4.16-1'

	PATH='/usr/bin:/bin:/usr/sbin:/sbin'

	current_macos_version="$(sw_vers -productVersion)"

	echo "Running \"$(basename "${BASH_SOURCE[0]}")\" version ${SCRIPT_VERSION} on macOS ${current_macos_version} $(sw_vers -buildVersion)..."

	mac_board_id=''
	mac_device_id=''

	mac_is_apple_silicon="$([[ "$(sysctl -in hw.optional.arm64)" == '1' ]] && echo 'true' \|\| echo 'false')"

	if [[ " $(sysctl -in machdep.cpu.features) " == ' VMM ' \|\| "$(sysctl -in kern.hv_vmm_present)" == '1' ]]; then
	# "machdep.cpu.features" is always EMPTY on Apple Silicon (whether or not it's a VM) so it cannot be used to check for the "VMM" feature flag when the system is a VM,
	# but I examined the full "sysctl -a" output when running a VM on Apple Silicon and found that "kern.hv_vmm_present" is set to "1" when running a VM and "0" when not.
	# Through testing, I found the "kern.hv_vmm_present" key is also the present on Intel Macs starting with macOS 11 Big Sur and gets properly set to "1"
	# on Intel VMs, but still check for either since "kern.hv_vmm_present" is not available on every version of macOS that this script may be run on.

	mac_device_id="$($mac_is_apple_silicon && echo 'VMA2MACOSAP' \|\| echo 'VMM-x86_64')" # These are the Device IDs listed in the "Apple Software Lookup Service" JSON for Apple Silicon and Intel VMs.
	else
	if ! $mac_is_apple_silicon; then # Only Intel Macs have a Board ID. T2 Macs (which are Intel) will have both a Board ID and Device ID while Apple Silicon Macs only have a Device ID.
	mac_board_id="$(/usr/libexec/PlistBuddy -c 'Print 0:board-id' /dev/stdin <<< "$(ioreg -arc IOPlatformExpertDevice -k board-id -d 1)" 2> /dev/null \| tr -d '[:cntrl:]')" # Remove control characters because this decoded value could end with a NUL char.

	if [[ "${mac_board_id}" != 'Mac-'* ]]; then
	>&2 echo 'ERROR: Failed to retrieve Board ID for Intel Mac.'
	exit 2
	fi
	fi

	if [[ -n "$(ioreg -rc AppleSEPManager)" ]]; then # The Device ID only exists for T2 and Apple Silicon Macs, both of which have a Secure Enclave (SEP).
	if $mac_is_apple_silicon; then # For Apple Silicon Macs, the Device ID is the first element of the "compatible" array in "ioreg -rc IOPlatformExpertDevice -d 1"
	# Annoyingly, the "compatible" array is easier to get elements out of from the plain text output rather than the plist output since the value is not actually a proper plist array.
	# NOTE: This "compatible" array will also exist on Intel Macs, but it will only contain the Model ID which was already retrieved above.
	mac_device_id="$(ioreg -rc IOPlatformExpertDevice -k compatible -d 1 \| awk -F '"' '($2 == "compatible") { print $4; exit }')"
	else
	mac_device_id="$(/usr/libexec/remotectl get-property localbridge HWModel 2> /dev/null)" # For T2 Macs, this is the T2 chip Device ID.
	fi

	if [[ "${mac_device_id}" != *'AP' ]]; then
	>&2 echo 'ERROR: Failed to retrieve Device ID for T2 or Apple Silicon Mac.'
	exit 3
	fi
	fi
	fi

	asls_url='https://gdmf.apple.com/v2/pmv'
	# About "Apple Software Lookup Service" (from https://support.apple.com/guide/deployment/use-mdm-to-deploy-software-updates-depafd2fad80/1/web/1.0#dep0b094c8d3 & https://developer.apple.com/business/documentation/MDM-Protocol-Reference.pdf):
	# Use the service at https://gdmf.apple.com/v2/pmv to obtain a list of available updates.
	# The JSON response contains two lists of available software releases. The "AssetSets" list contains all the releases available for MDMs to push to their supervised devices.
	# The other list, "PublicAssetSets" contains the latest releases available to the general public (non-supervised devices) if they try to upgrade. The "PublicAssetSets" is a subset of the "AssetSets" list.
	# Each element in the list contains the product version number of the OS, the posting date, the expiration date, and a list of supported devices for that release.

	if ! asls_json="$(curl -m 5 -sfL "${asls_url}")" \|\| [[ "${asls_json}" != '"PublicAssetSets"' ]]; then
	>&2 echo 'ERROR: Failed to download Apple Software Lookup Service JSON.'
	exit 4
	fi

	compatible_supported_macos_versions="$(osascript -l JavaScript -e '
	"use strict"
	function run(argv) {
	const macBoardID = argv[0], macDeviceID = argv[1], supportedVersion = []
	JSON.parse(argv[2]).PublicAssetSets.macOS.forEach(thisVersionDict => {
	const thisVersionSupportedDevices = thisVersionDict.SupportedDevices
	if ((macBoardID && thisVersionSupportedDevices.includes(macBoardID)) \|\| (macDeviceID && thisVersionSupportedDevices.includes(macDeviceID)))
	supportedVersion.push(thisVersionDict.ProductVersion)
	})
	return supportedVersion.sort((thisVersion, thatVersion) => ObjC.wrap(thatVersion).compareOptions(thisVersion, $.NSNumericSearch)).join("\n")
	}
	' -- "${mac_board_id}" "${mac_device_id}" "${asls_json}" 2> /dev/null)"

	echo -e "\nLatest Compatible macOS Version: $(echo "${compatible_supported_macos_versions}" \| head -1)"

	current_macos_major_version="${current_macos_version%%.*}"
	echo -e "\nLatest Version of macOS ${current_macos_major_version} (Running Version): $(echo "${compatible_supported_macos_versions}" \| grep -m 1 "^${current_macos_major_version}")"

	echo -e "\nAll Compatible Supported macOS Versions:\n${compatible_supported_macos_versions}"