1ec5783cbSrsc 2ec5783cbSrsc 38be7e703SrscThe source listing is preceded by a cross-reference that lists every defined 4ec5783cbSrscconstant, struct, global variable, and function in xv6. Each entry gives, 5ec5783cbSrscon the same line as the name, the line number (or, in a few cases, numbers) 6ec5783cbSrscwhere the name is defined. Successive lines in an entry list the line 7ec5783cbSrscnumbers where the name is used. For example, this entry: 8ec5783cbSrsc 9*49d64d33SAustin Clements swtch 2658 10*49d64d33SAustin Clements 0374 2428 2466 2657 2658 11ec5783cbSrsc 12*49d64d33SAustin Clementsindicates that swtch is defined on line 2658 and is mentioned on five lines 13*49d64d33SAustin Clementson sheets 03, 24, and 26. 14