LCARS Scrollbar + Context Menu + PCI Config Space + Bochs BGA — Lumen UI Kit Complete

Two more LCARS widgets complete the Lumen UI kit: lcars_scrollbar (proportional thumb + black track, 3-case oracle PASS) and lcars_menu_item (right-click context menu cell, orange+tan selected / black+ltblue normal, 8-char AA label, purple separator). sigil-drivers adds PCI configuration space (i440FX host bridge, 4-device bus 0 enum, CLS_BUS_PCI) and Bochs BGA display driver (1024×768×32 + 800×600×32 mode-set, XRES/YRES/BPP/ENABLE r/w, CLS_DISPLAY). (sigil-video f6dd8e4, 51f6eab; sigil-drivers f34debe, 6e12d4e)

lcars_scrollbar proportional thumb positions — lcars_scrollbar: proportional thumb at top, bottom, and full-fill (view≥total). LCARS-SCROLLBAR-PASS.

lcars_menu_item selected and normal cells — lcars_menu_item: selected (orange+tan AA) and normal (black+ltblue) cells with purple separator. LCARS-MENU-PASS.

lcars_scrollbar — Vertical Scroll Bar Widget (f6dd8e4)

lcars_scrollbar(fb, pitch, x, y, w, h, view, total, offset, color) draws a vertical scrollbar with a proportional thumb positioned to reflect the current scroll offset within a content range.

Black track background fills the full bar area first.
Proportional thumb: thumb_h = h * view / total, floored at 4 px minimum so the thumb is always grabbable.
Thumb position: thumb_y = y + offset * (h - thumb_h) / (total - view) — the thumb travels the full track range as offset goes from 0 to total - view.
Full-fill case: when view >= total, a full-height thumb is drawn (no scrolling needed).
Caller passes lcars_gold() or lcars_blue() as color, or any ARGB value.
GPU path: gpu_submit rect-fill (CAP_ACCEL; silicon-pending). SW path: fill_span rows.

Test: 3 cases — offset=0 (thumb at top), offset=75 (thumb at bottom), view=total (full-height thumb). 6 oracles: thumb/track pixels verified at all three positions. LCARS-SCROLLBAR-PASS top_thumb=ok top_track=ok bot_thumb=ok bot_track=ok full=ok.

lcars_menu_item — Right-Click Context Menu Cell (51f6eab)

lcars_menu_item(fb, pitch, fbw, fbh, x, y, w, h, selected, sep, c0..c7) draws a single menu cell with full LCARS styling. The OS stacks cells vertically to build right-click context menus on the Lumen desktop.

selected=1

Orange background + tan AA text label. The hovered or keyboard-active menu item.

selected=0

Black background + ltblue text. Normal (unselected) menu item.

sep=1

1 px purple bottom separator drawn below the cell — used to divide stacked items into logical groups.

c0..c7

Up to 8 characters rendered via lcars_gch_cov (AA cov_blend path). Left-padded 4 px.

GPU path: gpu_submit rect-fill + lcars_gch_cov per glyph (CAP_ACCEL; silicon-pending). Test: 2 stacked items — selected "O" (orange+tan+purple sep) + normal "S" (black+ltblue). 5 oracles: sel_bg, sel_sep, sel_glyph, norm_bg, norm_glyph. LCARS-MENU-PASS.

The Complete Lumen LCARS UI Kit

With lcars_scrollbar and lcars_menu_item landed, the Lumen LCARS UI kit is now complete across all desktop surface categories — 17 public functions, plus utility widgets bringing the total to 20+ functions.

Category	Functions
Primitives	`fill_rect`, `fill_circle`, `fill_qcircle_br`, `hbar`, `elbow`, `border_rect`, `resize_handle`
Desktop chrome	`panel_header`, `statusbar`, `boot_banner`, `boot_progress`
Window chrome	`window_chrome`, `wchrome_title`, `focus_chrome`
WM interaction	`resize_feedback`, `snap_zones`
App UI	`taskbar_item`, `scrollbar`, `menu_item`

The lcars_label / lcars_progress / lcars_data_strip utility widgets extend the kit to a complete design-language API. Any Lumen app can be built entirely from these primitives and remain visually consistent with the LCARS desktop chrome.

PCI Configuration Space — sigil-drivers (f34debe)

drivers/bus/pci-cfg implements PCI configuration space access via the standard x86 I/O port pair.

Address port 0xCF8, data port 0xCFC. Address format: bit 31 = enable, bits 23–16 = bus, bits 15–11 = device, bits 10–8 = function, bits 7–2 = register.
pci_read(bus, dev, fn, reg) / pci_write(bus, dev, fn, reg, val) via outd/ind.
Live QEMU: i440FX host bridge at 0:0:0 (vendor=0x8086, device=0x1237), class=bridge (0x06).
pci_enum(bus=0, dev=0..31) finds 4 devices on bus 0.
CLS_BUS_PCI dispatcher: OP_READ / WRITE / INIT / PROBE / CTL_ENUM. State at 0x880000.

Significance: PCI config space enumeration enables NVMe, e1000, and AHCI device discovery. Without it, the kernel cannot find any expansion devices at boot — every bus-connected peripheral is invisible until config space is readable.

Bochs BGA Display Driver — sigil-drivers (6e12d4e)

drivers/display/bga implements the Bochs VBE Extensions (BGA) display driver, enabling native framebuffer mode-setting in QEMU without BIOS or VESA calls.

I/O ports 0x1CE (index) and 0x1CF (data) — 16-bit outw/inw.
Registers: VBE_DISPI_INDEX_ID (0), XRES (1), YRES (2), BPP (3), ENABLE (4), BANK (5), VIRT_W (6), VIRT_H (7), X_OFFSET (8), Y_OFFSET (9).
Live QEMU: BGA ID = 0xB0C5. XRES/YRES/BPP/ENABLE read/write round-trips verified.
Mode-set sequence: ENABLE=0 (disable) → write XRES/YRES/BPP → ENABLE=65 (LFB enabled + 8-bit DAC).
Tested modes: 1024×768×32 and 800×600×32.
CLS_DISPLAY dispatcher: CTL_SET_MODE / CTL_GET_ID. State at 0x890000.

Significance: The BGA driver enables framebuffer mode-setting without BIOS/VESA calls. Combined with the PCI enumerator, the kernel can find the Bochs display device, read its BGA ID, and set a native resolution before any UEFI/GOP path is available. This is the x86 display bootstrap path.

Driver summary — batch

Driver	Commit	Repo	Class	State addr
`lcars_scrollbar`	`f6dd8e4`	sigil-video	UI widget	—
`lcars_menu_item`	`51f6eab`	sigil-video	UI widget	—
`pci-cfg`	`f34debe`	sigil-drivers	CLS_BUS_PCI	`0x880000`
`bga`	`6e12d4e`	sigil-drivers	CLS_DISPLAY	`0x890000`