#!/usr/bin/env bash
# SPDX-License-Identifier: GPL-2.0-only
# Modified for s390x cross-architecture support

build() {
    local applet
    
    echo "=== S390X BASE HOOK STARTING ==="
    
    # Use s390x busybox binary if available (cross-architecture support)
    if [[ -f "/work/boot/busybox-s390x-static" ]]; then
        echo "Using s390x static busybox binary"
        add_file "/work/boot/busybox-s390x-static" "/usr/bin/busybox" 755
        
        # Create symlinks for busybox applets (using a known list since we can't execute cross-arch binary)
        local busybox_applets=(
            "[" "[[" "ash" "awk" "basename" "cat" "chgrp" "chmod" "chown" "cp" "cut"
            "date" "dd" "df" "dirname" "dmesg" "du" "echo" "env" "expr" "false"
            "find" "grep" "head" "hostname" "id" "kill" "ln" "ls" "mkdir" "mknod"
            "mktemp" "mount" "mv" "printf" "ps" "pwd" "readlink" "rm" "rmdir"
            "sed" "sh" "sleep" "sort" "stat" "switch_root" "tail" "tar" "test" "touch" "tr"
            "true" "umount" "uname" "uniq" "wc" "which" "whoami" "xargs"
        )
        
        for applet in "${busybox_applets[@]}"; do
            add_symlink "/usr/bin/$applet" busybox
        done
        
        # Manually add switch_root symlink (critical for root filesystem switching)
        add_symlink "/usr/bin/switch_root" busybox
    elif [[ -f "/work/boot/busybox-s390x-native" ]]; then
        echo "Using s390x busybox binary"
        add_file "/work/boot/busybox-s390x-native" "/usr/bin/busybox" 755
        
        # Create symlinks for busybox applets (using a known list since we can't execute cross-arch binary)
        local busybox_applets=(
            "[" "[[" "ash" "awk" "basename" "cat" "chgrp" "chmod" "chown" "cp" "cut"
            "date" "dd" "df" "dirname" "dmesg" "du" "echo" "env" "expr" "false"
            "find" "grep" "head" "hostname" "id" "kill" "ln" "ls" "mkdir" "mknod"
            "mktemp" "mount" "mv" "printf" "ps" "pwd" "readlink" "rm" "rmdir"
            "sed" "sh" "sleep" "sort" "stat" "switch_root" "tail" "tar" "test" "touch" "tr"
            "true" "umount" "uname" "uniq" "wc" "which" "whoami" "xargs"
        )
        
        for applet in "${busybox_applets[@]}"; do
            add_symlink "/usr/bin/$applet" busybox
        done
        
        # Manually add switch_root symlink (critical for root filesystem switching)
        add_symlink "/usr/bin/switch_root" busybox
    else
        echo "Warning: s390x busybox not found, using system busybox (may cause architecture mismatch)"
        # Try to find busybox in various locations
        if [[ -f /usr/lib/initcpio/busybox ]]; then
            add_binary /usr/lib/initcpio/busybox /bin/busybox
        elif [[ -f /usr/bin/busybox ]]; then
            add_binary /usr/bin/busybox /bin/busybox
        elif [[ -f /bin/busybox ]]; then
            add_binary /bin/busybox /bin/busybox
        else
            echo "ERROR: No busybox binary found!"
            return 1
        fi
        # Get applet list from the binary we found
        for applet in $(busybox --list 2>/dev/null || echo "sh ash"); do
            add_symlink "/usr/bin/$applet" busybox
        done
    fi

    # Add kmod with applet symlinks (if available)
    if type -P kmod >/dev/null 2>&1; then
        echo "Adding kmod utilities..."
        add_binary kmod
        for applet in {dep,ins,rm,ls}mod mod{probe,info}; do
            add_symlink "/usr/bin/$applet" kmod
        done
    else
        echo "Warning: kmod not found, module utilities will not be available"
    fi

    # Check for additional utilities (may not be available in cross-compile environment)
    # IMPORTANT: Skip mount/umount as they should come from busybox to avoid arch mismatch
    for binary in blkid switch_root; do
        if type -P "$binary" >/dev/null 2>&1; then
            echo "Adding $binary"
            add_binary "$binary"
        else
            echo "Warning: $binary not found, skipping (functionality may be limited)"
        fi
    done

    # Ensure switch_root symlink exists (critical for root filesystem switching)
    echo "Ensuring switch_root symlink..."
    add_symlink "/usr/bin/switch_root" busybox

    # Always add init files
    echo "Adding init files..."
    # Check both lib and lib64 locations for init files
    if [[ -f /usr/lib/initcpio/init_functions ]]; then
        add_file "/usr/lib/initcpio/init_functions" "/init_functions" 644
    elif [[ -f /usr/lib64/initcpio/init_functions ]]; then
        add_file "/usr/lib64/initcpio/init_functions" "/init_functions" 644
    else
        echo "ERROR: init_functions not found in /usr/lib/initcpio or /usr/lib64/initcpio"
        return 1
    fi
    
    # Use standard Arch init but patch the switch_root call
    echo "Patching standard init script for s390x..."
    
    # Copy the standard init and patch it
    if [[ -f /usr/lib/initcpio/init ]]; then
        cp /usr/lib/initcpio/init /tmp/s390x_init
    elif [[ -f /usr/lib64/initcpio/init ]]; then
        cp /usr/lib64/initcpio/init /tmp/s390x_init
    else
        echo "ERROR: Standard init not found"
        return 1
    fi
    
    # Patch the switch_root line to use busybox
    sed -i 's|/usr/bin/switch_root|/usr/bin/busybox switch_root|g' /tmp/s390x_init
    
    # Add debug break when udevadm fails - use a more aggressive replacement
    sed -i 's|udevadm settle|echo ":: udevadm not available, dropping to shell"; /bin/sh|g' /tmp/s390x_init
    
    # Add the patched init script to the initramfs
    add_file "/tmp/s390x_init" "/init" 755
    echo "✓ Standard Arch init patched for s390x (switch_root -> busybox switch_root)"
    echo "=== S390X BASE HOOK COMPLETED ==="
}

help() {
    cat <<HELPEOF
This hook provides crucial runtime necessities for booting. This is a modified 
version with s390x cross-architecture support. DO NOT remove this hook unless 
you know what you're doing.
HELPEOF
}

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