HelenOS sources

ahci_cmdhdr_t     962 uspace/drv/block/ahci/ahci.c 	sata->cmd_header = (ahci_cmdhdr_t *) virt_cmd;
ahci_cmdhdr_t      76 uspace/drv/block/ahci/ahci.h 	volatile ahci_cmdhdr_t *cmd_header;
HelenOS homepage, sources at GitHub