initrd/etc/gui_functions pause_automatic_boot: show TOTP code while waiting for automatic boot is set and hotp is valid

[tlaurion]

This pull request refactors the pause_automatic_boot function in initrd/etc/gui_functions to improve user experience and add TOTP display support during the automatic boot countdown. The main changes include switching to a live countdown display, optionally showing the current TOTP code, and handling user interruption more interactively.

User experience improvements:

• The boot countdown now updates live on the same line, showing the remaining seconds and the current UTC timestamp, instead of a static message.
• If TPM and TOTP are enabled and QR code display is not skipped, the current TOTP code is shown alongside the countdown. Errors in retrieving the TOTP are handled gracefully.

Interactive interruption:

• The function checks for user keypresses every second during the countdown, allowing interruption at any time, and prints a newline for clarity after an interrupt.

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In action under qemu-coreboot-whiptail-tpm2-hotp-prod (not silent, not debug):

[tlaurion]

Old OP (in link of deprecated superseeded commit e0fb3e7)

This pull request enhances the user experience during the automatic boot countdown in the initrd/etc/gui_functions script. The main improvement is the addition of a dynamic countdown display that updates every second and optionally shows the current TOTP code if TPM is enabled and QR code display is not skipped.

User experience improvements:

• The automatic boot countdown now updates every second, providing a more interactive and visible countdown for the user.
• If TPM is enabled and QR code display is not skipped, the current TOTP code is retrieved and displayed alongside the countdown, giving users immediate access to authentication information.
• The script checks for a keypress each second, allowing the user to interrupt the boot process at any time during the countdown.

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In action under qemu-coreboot-whiptail-tpm2-hotp-prod (not silent, not debug):

[tlaurion]

Small UX bug to fix, time shown on screen is updated every 2 seconds, not every seconds.

[tlaurion]

Self reviewed. @JonathonHall-Purism comments?

[Copilot]

Pull Request Overview

This PR refactors the pause_automatic_boot function to provide an enhanced user experience during the automatic boot countdown with live updates and optional TOTP display. The changes replace a simple single-line timeout with an interactive countdown loop.

• Implements live countdown display that updates every second with current UTC timestamp
• Adds optional TOTP code display when TPM is enabled and QR code display is not skipped
• Enables real-time user interruption by checking for keypresses every second

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[Copilot]

The function calls die when TOTP unsealing fails, which will terminate the entire process. This contradicts the PR description which states that 'Errors in retrieving the TOTP are handled gracefully.' Consider continuing the countdown without TOTP display instead of terminating.

Suggested change

	if ! current_totp=$(unseal-totp 2>/dev/null); then
	die "Failed to unseal TOTP"
	fi
	status_line="$status_line | TOTP: $current_totp"
	if current_totp=$(unseal-totp 2>/dev/null); then
	status_line="$status_line | TOTP: $current_totp"
	fi

[Copilot]

The sleep_time variable should be quoted to prevent word splitting issues when passed to the -t option. Use \"$sleep_time\" instead of $sleep_time.

Suggested change

	if IFS= read -t $sleep_time -s -n 1 -r; then
	if IFS= read -t "$sleep_time" -s -n 1 -r; then

[Copilot]

If the loop processing takes longer than 1 second, sleep_time becomes 0, but the countdown will still decrement by 1. This could cause the countdown to complete faster than the configured timeout. Consider adjusting the remaining time based on actual elapsed time instead of always decrementing by 1.