diff options
Diffstat (limited to 'hw/usb/desc.c')
| -rw-r--r-- | hw/usb/desc.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/hw/usb/desc.c b/hw/usb/desc.c index 3c77368..e8a3c6a 100644 --- a/hw/usb/desc.c +++ b/hw/usb/desc.c @@ -1,3 +1,5 @@ +#include <ctype.h> + #include "hw/usb.h" #include "hw/usb/desc.h" #include "trace.h" @@ -412,6 +414,36 @@ void usb_desc_set_string(USBDevice *dev, uint8_t index, const char *str) s->str = g_strdup(str); } +/* + * This function creates a serial number for a usb device. + * The serial number should: + * (a) Be unique within the virtual machine. + * (b) Be constant, so you don't get a new one each + * time the guest is started. + * So we are using the physical location to generate a serial number + * from it. It has three pieces: First a fixed, device-specific + * prefix. Second the device path of the host controller (which is + * the pci address in most cases). Third the physical port path. + * Results in serial numbers like this: "314159-0000:00:1d.7-3". + */ +void usb_desc_create_serial(USBDevice *dev) +{ + DeviceState *hcd = dev->qdev.parent_bus->parent; + const USBDesc *desc = usb_device_get_usb_desc(dev); + int index = desc->id.iSerialNumber; + char serial[64]; + int dst; + + assert(index != 0 && desc->str[index] != NULL); + dst = snprintf(serial, sizeof(serial), "%s", desc->str[index]); + if (hcd && hcd->parent_bus && hcd->parent_bus->info->get_dev_path) { + char *path = hcd->parent_bus->info->get_dev_path(hcd); + dst += snprintf(serial+dst, sizeof(serial)-dst, "-%s", path); + } + dst += snprintf(serial+dst, sizeof(serial)-dst, "-%s", dev->port->path); + usb_desc_set_string(dev, index, serial); +} + const char *usb_desc_get_string(USBDevice *dev, uint8_t index) { USBDescString *s; |