feature: Add ELF metadata support

tools/gen_userland_note.sh

@@ -0,0 +1,147 @@
+#!/usr/bin/env sh
+set -eu
+
+if [ "$#" -ne 4 ]; then
+    echo "usage: gen_userland_note.sh <app-name> <source-file> <icon-source-dir> <output-c>" >&2
+    exit 1
+fi
+
+APP_NAME="$1"
+SOURCE_PATH="$2"
+ICON_SOURCE_DIR="$3"
+OUT_PATH="$4"
+
+MAX_APP_NAME=63
+MAX_DESC=191
+MAX_IMAGE_PATH=159
+MAX_IMAGES=4
+
+DEFAULT_ICON_PATH="/Library/images/icons/colloid/xterm.png"
+DEFAULT_DESC="BoredOS userspace application."
+
+escape_c_string() {
+    printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g'
+}
+
+trim_spaces() {
+    printf '%s' "$1" | sed 's/^[[:space:]]*//; s/[[:space:]]*$//'
+}
+
+truncate_bytes() {
+    value="$1"
+    max_len="$2"
+    printf '%s' "$value" | cut -c1-"$max_len"
+}
+
+if [ ! -f "$SOURCE_PATH" ]; then
+    echo "error: source file '$SOURCE_PATH' not found for app '$APP_NAME'" >&2
+    exit 1
+fi
+
+app_desc="$DEFAULT_DESC"
+image_spec="$DEFAULT_ICON_PATH"
+
+source_desc=$(sed -n 's@^[[:space:]]*//[[:space:]]*BOREDOS_APP_DESC:[[:space:]]*@@p' "$SOURCE_PATH" | head -n 1)
+source_icons=$(sed -n 's@^[[:space:]]*//[[:space:]]*BOREDOS_APP_ICONS:[[:space:]]*@@p' "$SOURCE_PATH" | head -n 1)
+
+if [ -n "$source_desc" ]; then
+    app_desc="$source_desc"
+fi
+if [ -n "$source_icons" ]; then
+    image_spec="$source_icons"
+fi
+
+app_desc=$(trim_spaces "$app_desc")
+if [ -z "$app_desc" ]; then
+    app_desc="$DEFAULT_DESC"
+fi
+
+image_spec=$(trim_spaces "$image_spec")
+if [ -z "$image_spec" ]; then
+    image_spec="$DEFAULT_ICON_PATH"
+fi
+
+app_name_value=$(truncate_bytes "$APP_NAME" "$MAX_APP_NAME")
+app_desc=$(truncate_bytes "$app_desc" "$MAX_DESC")
+
+IMAGE_1=""
+IMAGE_2=""
+IMAGE_3=""
+IMAGE_4=""
+IMAGE_COUNT=0
+
+saved_ifs="$IFS"
+IFS=';'
+for raw_image in $image_spec; do
+    image_path=$(trim_spaces "$raw_image")
+    if [ -z "$image_path" ]; then
+        continue
+    fi
+    image_path=$(truncate_bytes "$image_path" "$MAX_IMAGE_PATH")
+
+    image_file="${image_path##*/}"
+    if [ ! -f "$ICON_SOURCE_DIR/$image_file" ]; then
+        echo "error: icon '$image_file' (from '$image_path') not found in $ICON_SOURCE_DIR for app '$APP_NAME'" >&2
+        exit 1
+    fi
+
+    IMAGE_COUNT=$((IMAGE_COUNT + 1))
+    if [ "$IMAGE_COUNT" -gt "$MAX_IMAGES" ]; then
+        break
+    fi
+
+    case "$IMAGE_COUNT" in
+        1) IMAGE_1="$image_path" ;;
+        2) IMAGE_2="$image_path" ;;
+        3) IMAGE_3="$image_path" ;;
+        4) IMAGE_4="$image_path" ;;
+    esac
+done
+IFS="$saved_ifs"
+
+if [ "$IMAGE_COUNT" -eq 0 ]; then
+    IMAGE_1="$DEFAULT_ICON_PATH"
+    IMAGE_COUNT=1
+fi
+
+app_name_escaped=$(escape_c_string "$app_name_value")
+app_desc_escaped=$(escape_c_string "$app_desc")
+image_1_escaped=$(escape_c_string "$IMAGE_1")
+image_2_escaped=$(escape_c_string "$IMAGE_2")
+image_3_escaped=$(escape_c_string "$IMAGE_3")
+image_4_escaped=$(escape_c_string "$IMAGE_4")
+
+cat > "$OUT_PATH" <<EOF
+#include <stdint.h>
+#include "elf.h"
+
+struct __attribute__((packed, aligned(4))) boredos_app_note_blob {
+    Elf64_Word namesz;
+    Elf64_Word descsz;
+    Elf64_Word type;
+    char name[sizeof(BOREDOS_APP_NOTE_NAME)];
+    boredos_app_metadata_t metadata;
+};
+
+__attribute__((used, section(".note.boredos.app"), aligned(4)))
+static const struct boredos_app_note_blob g_boredos_app_note = {
+    .namesz = sizeof(BOREDOS_APP_NOTE_NAME),
+    .descsz = sizeof(boredos_app_metadata_t),
+    .type = BOREDOS_APP_NOTE_TYPE,
+    .name = BOREDOS_APP_NOTE_NAME,
+    .metadata = {
+        .magic = BOREDOS_APP_METADATA_MAGIC,
+        .version = BOREDOS_APP_METADATA_VERSION,
+        .image_count = ${IMAGE_COUNT},
+        .reserved = 0,
+        .app_name = "${app_name_escaped}",
+        .description = "${app_desc_escaped}",
+        .images = {
+            "${image_1_escaped}",
+            "${image_2_escaped}",
+            "${image_3_escaped}",
+            "${image_4_escaped}",
+        },
+    },
+};
+EOF