Hello,
I got further with the USB driver for OpenBIOS but there's a part I don't
understand. When configuring the keyboard it tries to get the HID
descriptor to find out the keyboard layout from the country code (even
though it only supports us layout so I can just skip all this for now).
The descriptor is defined in hw/usb/dev-hid.c here:
167 static const USBDescIface desc_iface_keyboard = {
168 .bInterfaceNumber = 0,
169 .bNumEndpoints = 1,
170 .bInterfaceClass = USB_CLASS_HID,
171 .bInterfaceSubClass = 0x01, /* boot */
172 .bInterfaceProtocol = 0x01, /* keyboard */
173 .ndesc = 1,
174 .descs = (USBDescOther[]) {
175 {
176 /* HID descriptor */
177 .data = (uint8_t[]) {
178 0x09, /* u8 bLength */
179 USB_DT_HID, /* u8 bDescriptorType */
180 0x11, 0x01, /* u16 HID_class */
181 0x00, /* u8 country_code */
182 0x01, /* u8 num_descriptors */
183 USB_DT_REPORT, /* u8 type: Report */
184 0x3f, 0, /* u16 len */
185 },
186 },
187 },
To query the above HID descriptor the driver sends this packet:
ED @ 0x07c9b8c0 fa=1 en=0 d=3 s=0 k=0 f=0 mps=8 h=0 c=0
head=0x07c9b840 tailp=0x07c9b8a0 next=0x00000000
TD @ 0x07c9b840 8 of 8 bytes setup r=0 cbp=0x07df75f8 be=0x07df75ff
data: 81 06 00 21 00 00 08 00
Which is generated with these parameters:
bmRequestType = (device_to_host, standard_type, iface_recp)
bRequest = GET_DESCRIPTOR
wValue = (0x21, 0)
thus I think it sends it as an InterfaceRequest and results in:
status=-3
usb-ohci: got STALL
HALTED!
getting descriptor size (type 21) failed
the code in hw/usb/dev-hid.c:usb_hid_handle_control() only checks for 0x22
for InterfaceRequests here (by the way there's a #define for this number
earlier in this file which is not used here):
458 switch (request) {
459 /* hid specific requests */
460 case InterfaceRequest | USB_REQ_GET_DESCRIPTOR:
461 switch (value >> 8) {
--> 462 case 0x22:
463 if (hs->kind == HID_MOUSE) {
464 memcpy(data, qemu_mouse_hid_report_descriptor,
465 sizeof(qemu_mouse_hid_report_descriptor));
and only accepts DeviceRequests in hw/usb/desc.c:usb_desc_handle_control()
that is called before the above:
733 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
734 ret = usb_desc_get_descriptor(dev, p, value, data, length);
735 break;
What am I missing? Is the driver erroneously sending an incorrect request
or should the emulation handle this case as well?
Regards,
BALATON Zoltan
