Record networking and DMA development progress

Add the current OS source tree, build scripts, system image layout, and development notes covering DMA page allocation, e1000 bring-up, net API dispatch, and DHCP work in progress.

CODE/font/render_text.py

@@ -0,0 +1,31 @@
+"""render_text.py — pre-render specific Chinese strings to C arrays"""
+from PIL import Image, ImageFont, ImageDraw
+
+def render(ttf, texts, size, var_prefix):
+    font = ImageFont.truetype(ttf, size)
+    for name, text in texts:
+        w = font.getbbox(text)[2]
+        h = size + 4
+        img = Image.new("L", (w, h), 0)
+        draw = ImageDraw.Draw(img)
+        draw.text((0, 2), text, font=font, fill=255)
+
+        pixels = list(img.tobytes())
+        print(f"/* {text} — {w}x{h} */")
+        print(f"static const int {var_prefix}_{name}_w = {w};")
+        print(f"static const int {var_prefix}_{name}_h = {h};")
+        print(f"static const unsigned char {var_prefix}_{name}_data[{w}*{h}] = {{")
+        for y in range(h):
+            row = ", ".join(str(pixels[y*w + x]) for x in range(w))
+            print(f"  {row},")
+        print("};")
+        print()
+
+texts = [
+    ("welcome", "欢迎使用 Deshab"),
+    ("setup",   "接下来让我们来引导你设置你的系统"),
+]
+# Generate for multiple sizes
+for sz in [24]:
+    print(f"// ===== size={sz}px =====")
+    render("SYSTEM/system/font/simhei.ttf", texts, sz, f"txt{sz}")