hi,

diff below seems to let me use igfx on a thinkpad x1 carbon
3rd gen with a broadwell chipset.

% cat /dev/vgactl
type igfx
size 2560x1440x32 x8r8g8b8
tilt none
hwgc soft
hwaccel off
hwblank off
addr p 0xc0000000 v 0xffffff00c0000000 size 0x4000000
softscreen on

i tried using the hdmi port on the side but the tv did not
get a signal. i have been testing it lightly and there does
not seem to be much difference from vesa.


diff c7775b365ef3e73748f23b7ace521214753de2a7 uncommitted
--- a/lib/vgadb
+++ b/lib/vgadb
@@ -438,6 +438,7 @@
 	vid=0x8086 did=0x2a42	# Intel 4 Series Mobile
 	vid=0x8086 did=0x0a16	# Intel 4th Gen Core (HD 4400)
 	vid=0x8086 did=0x0412	# Intel 4th Gen Core (HD 4600)
+	vid=0x8086 did=0x1616	# Intel 5th Gen Core (HD 5500)
 	vid=0x8086 did=0x3185	# Intel 9.5th Gen Core (UHD 600)
 	vid=0x8086 did=0x0a06
 	link=vga
--- a/sys/src/cmd/aux/vga/igfx.c
+++ b/sys/src/cmd/aux/vga/igfx.c
@@ -368,6 +368,7 @@
 		/* wet floor */
 	case 0x0a06:
 	case 0x3185:    /* UHD 600 - 9.5 Gen Core */
+	case 0x1616:	/* HD 5500 - 5th Gen Core */
 	case 0x0412:	/* HD 4600 - 4th Gen Core */
 		return TypeHSW;
 	case 0x0166:	/* 3rd Gen Core - ThinkPad X230 */