Boot manager: Niveus window, keys and wells, Instrument Sans, pointer, other systems, working power entries

The F8 menu is redrawn in the Niveus language: a window with three lights,
bevelled keys with a lit edge, wells for panels, anti-aliased corners and a
soft shadow, set in Instrument Sans rasterised into include/gfx/nvfont.h
(tools/python/mknvfont.py, make nvfont). Scale doubles on screens 1400 px tall
or more. Lists taller than the screen scroll.

The keyboard still drives everything, and a mouse, touchpad or tablet does
too: both UEFI pointer protocols are polled, hover moves the highlight, a
click activates. The cursor stays hidden until the pointer has really done
something, since the firmware installs a pointer protocol with or without a
mouse. The 'keep this resolution?' countdown is one ten-second budget however
many times the pointer moves.

Loaders found at well-known paths on any volume (Windows, Ubuntu, Debian,
Fedora, Arch, openSUSE, systemd-boot, rEFInd, other BOOTX64.EFI) are listed
and chain-loaded with LoadImage/StartImage. 'Reboot to firmware' used to halt;
it now sets OsIndications and restarts, and Restart and Shut Down call
ResetSystem.

Checked under QEMU+OVMF: menu, resolution list (incl. 2560x1600 at double
scale), system information, shut down, firmware setup, chain-loading a copy of
the loader from a second disk, and a full boot of the ISO to the login prompt.
Pointer hover and click were checked only with synthetic events: in this setup
a USB mouse or tablet delivered no event to the loader (one USB I/O handle
appeared but no pointer protocol came from it), and why was not established.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EVRhxi9zpdW2uDUN4FVcao

tools/python/mknvfont.py

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""Rasterise Niveus's interface face into a header the boot manager can draw.
+
+The loader cannot carry a TrueType rasteriser, and the answer to that has been
+the same since include/gfx/font.h: do the work at build time and commit the
+result. This takes Instrument Sans (SIL OFL, see docs/Website/niveus/fonts/)
+at three sizes and writes 8-bit coverage bitmaps, one per printable ASCII
+character, with the metrics needed to lay them out proportionally.
+
+    python3 tools/python/mknvfont.py docs/Website/niveus/fonts/static include/gfx/nvfont.h
+
+Needs Pillow; nothing else, and nothing at all at build time of the OS.
+"""
+import sys, os
+from PIL import ImageFont
+
+# Each size twice: x1 for ordinary screens and x2 for the ones where a 15 px
+# face would be a speck. Rendering at the real size beats doubling pixels.
+SIZES = []
+for _scale in (1, 2):
+    SIZES += [
+        ("body%d"  % _scale, "InstrumentSans-Medium.ttf",   15 * _scale),
+        ("small%d" % _scale, "InstrumentSans-Regular.ttf",  12 * _scale),
+        ("title%d" % _scale, "InstrumentSans-SemiBold.ttf", 24 * _scale),
+    ]
+FIRST, LAST = 32, 126
+
+
+def render(path, px):
+    f = ImageFont.truetype(path, px)
+    asc, desc = f.getmetrics()
+    glyphs, blob = [], bytearray()
+    for code in range(FIRST, LAST + 1):
+        ch = chr(code)
+        adv = int(round(f.getlength(ch) * 64))   # 26.6 fixed point: whole-pixel advances make text look cramped
+        mask, (ox, oy) = f.getmask2(ch, mode="L", anchor="ls")
+        w, h = mask.size
+        data = bytes(mask) if (w and h) else b""
+        glyphs.append((len(blob), w, h, ox, oy, adv))
+        blob += data
+    return asc, desc, glyphs, blob
+
+
+def main():
+    src, out = sys.argv[1], sys.argv[2]
+    lines = [
+        "#pragma once",
+        "",
+        "// GENERATED by tools/python/mknvfont.py -- do not edit. Run `make nvfont`.",
+        "//   source: docs/Website/niveus/fonts/static (Instrument Sans, SIL OFL 1.1)",
+        "//",
+        "// 8-bit coverage bitmaps for printable ASCII, proportionally spaced, used by",
+        "// the boot manager (boot/common/ui.c). Not included by the kernel.",
+        "",
+        "struct nvglyph { unsigned short off; unsigned char w, h; signed char ox, oy; unsigned short adv; /* 1/64 px */ };",
+        "struct nvfont  { unsigned char ascent, descent; const struct nvglyph *g; const unsigned char *bits; };",
+        "#define NVFONT_FIRST %d" % FIRST,
+        "#define NVFONT_LAST  %d" % LAST,
+        "",
+    ]
+    for name, fn, px in SIZES:
+        asc, desc, glyphs, blob = render(os.path.join(src, fn), px)
+        lines.append("static const struct nvglyph nvg_%s[] = {" % name)
+        for (o, w, h, ox, oy, adv) in glyphs:
+            lines.append("    {%d,%d,%d,%d,%d,%d}," % (o, w, h, ox, oy, adv))
+        lines.append("};")
+        lines.append("static const unsigned char nvb_%s[] = {" % name)
+        for i in range(0, len(blob), 24):
+            lines.append("    " + ",".join(str(b) for b in blob[i:i + 24]) + ",")
+        if not blob:
+            lines.append("    0")
+        lines.append("};")
+        lines.append("static const struct nvfont nvfont_%s = { %d, %d, nvg_%s, nvb_%s };" %
+                     (name, asc, desc, name, name))
+        lines.append("")
+    open(out, "w").write("\n".join(lines) + "\n")
+    print("wrote", out)
+
+
+main()