Driver Fleet: WiFi, VGA Text, SRDX Transport, BT USB

sigil-drivers ships 6 production drivers: BCM43438/CYW43455 onboard WiFi (SDIO), VGA 80×25 color text console, bochs DISPI framebuffer, SRDX frame decoder (viewer-side), SRDX input reverse channel (viewer→host HID), and BT USB self-test. All on the CLS_NET / CLS_DISPLAY / CLS_INPUT seams with cap gates. (sigil-drivers fc2f97f, 0ce8313, 1960672, 71ee428, 76bfa36, def3347)

VGA text console (vt100/vga_text driver) — 80×25 color text PASS x86

BCM43438/CYW43455 WiFi (bcm43xx.sg, fc2f97f)

SDIO-attached Broadcom/Cypress WiFi for Pi 3B/Zero-W (BCM43438) and Pi 3B+/4/5 (CYW43455). The driver speaks the BCDC ioctl protocol: a 16-byte header over sdio_cmd53 on F2.

Command	Underlying ioctl
`CTL_WIFI_SCAN`	`WLC_SCAN` + `WLC_GET_SCANRESULTS`
`ASSOCIATE`	`WLC_JOIN`
`SET_KEY`	`WLC_SET_KEY`
`GET_SIGNAL`	`WLC_GET_RSSI`
`GET_STATE`	`WLC_GET_VAR`

Data path: OP_READ / OP_WRITE transfers 802.3 frames on SDIO F2. The bcm_op() entry point sits on the CLS_NET seam with cap gates. x86-runverify PASS.

VGA 80×25 Color Text (vga_text.sg, 0ce8313)

Direct MMIO at 0xB8000 — no PCI enumeration required. Text mode 2-byte cells (char + attribute byte). Full API:

vt_init, vt_cls — initialization and clear
vt_gotoxy, vt_set_attr — cursor positioning and color
vt_putc, vt_puts, vt_putd — character, string, decimal output
vt_scroll, vt_newline — scrolling and line advance

Color encoding: attr = fg + bg × 16. Hardware cursor is driven via VGA CRTC registers 14/15 (I/O ports 0x3D4/0x3D5). State block at VT_STATE()=0x730000. x86-runverify PASS.

Bochs DISPI Framebuffer (vga_bochs.sg, 1960672)

PCI probe by VID=0x1234 / DID=0x1111. BAR0 is the 64-bit VRAM aperture; BAR2 MMIO holds the DISPI register file at offset 0x500 (QEMU 11.0.1 layout). Resolution setup:

set_res(w, h, bpp):
  DISPI_ENABLE = 0          // disable
  DISPI_XRES = w
  DISPI_YRES = h
  DISPI_BPP  = bpp
  DISPI_ENABLE = 3          // LFB + enable

Surface operations: vb_fill(), vb_put_pixel(), vb_clear(). x86-runverify PASS with 1024×768 screendump.

SRDX Transport Drivers

SRDX delta decoder — 3-run packet applied, pixel values verified x86

srdx_encode.sg — viewer-side frame decoder (71ee428)

Receives SRDX delta packets from the host via Cap<NetConn> and applies pixel runs to the local framebuffer. Packet format: 8-byte header (magic=SRDX + width/height as LE16) followed by N × 8-byte run records (4B FB offset + 4B BGRA pixel value). x86-runverify PASS: 3-run packet applied, bad-magic input returns -1.

srdx_input.sg — reverse channel (76bfa36)

Viewer→host HID injection over Cap<Input>. 4-byte event records with sign-extension for relative deltas:

KEY_DOWN / KEY_UP — keycode events
MOUSE_REL — relative motion with signed delta extension
MOUSE_BTN — button state

Events inject into HID_ROUTER_STATE. 8-event sequence PASS.

BT USB (btusb_test.sg, def3347)

HCI command encoding via bt_pack_cmd (LE opcode + plen byte), bt_probe discovery, and standard HCI opcodes: HCI_RESET=3075, HCI_READ_BDADDR=4105. x86-runverify PASS. Real-hardware proof via raspi3b parallel track.

Fleet summary

Driver	File	Seam	Commit	Status
BCM43438/CYW43455 WiFi	`bcm43xx.sg`	`CLS_NET`	`fc2f97f`	PASS
VGA 80×25 text console	`vga_text.sg`	`CLS_DISPLAY`	`0ce8313`	PASS
Bochs DISPI framebuffer	`vga_bochs.sg`	`CLS_DISPLAY`	`1960672`	PASS
SRDX frame decoder	`srdx_encode.sg`	`CLS_NET`	`71ee428`	PASS
SRDX input reverse channel	`srdx_input.sg`	`CLS_INPUT`	`76bfa36`	PASS
BT USB self-test	`btusb_test.sg`	`CLS_NET`	`def3347`	PASS