Эта глава посвящена механизмам FreeBSD по написанию драйверов устройств, работающих на шине PCI.
Здесь находится информация о том, как код шины PCI проходит по неподключенным устройствам и распознает возможность загруженного драйвера kld выполнить подключение к какому-либо из них.
/* * Simple KLD to play with the PCI functions. * * Murray Stokely */ #define MIN(a,b) (((a) < (b)) ? (a) : (b)) #include <sys/types.h> #include <sys/module.h> #include <sys/systm.h> /* uprintf */ #include <sys/errno.h> #include <sys/param.h> /* defines used in kernel.h */ #include <sys/kernel.h> /* types used in module initialization */ #include <sys/conf.h> /* cdevsw struct */ #include <sys/uio.h> /* uio struct */ #include <sys/malloc.h> #include <sys/bus.h> /* structs, prototypes for pci bus stuff */ #include <pci/pcivar.h> /* For get_pci macros! */ /* Function prototypes */ d_open_t mypci_open; d_close_t mypci_close; d_read_t mypci_read; d_write_t mypci_write; /* Character device entry points */ static struct cdevsw mypci_cdevsw = { mypci_open, mypci_close, mypci_read, mypci_write, noioctl, nopoll, nommap, nostrategy, "mypci", 36, /* reserved for lkms - /usr/src/sys/conf/majors */ nodump, nopsize, D_TTY, -1 }; /* vars */ static dev_t sdev; /* We're more interested in probe/attach than with open/close/read/write at this point */ int mypci_open(dev_t dev, int oflags, int devtype, struct proc *p) { int err = 0; uprintf("Opened device \"mypci\" successfully.\n"); return(err); } int mypci_close(dev_t dev, int fflag, int devtype, struct proc *p) { int err=0; uprintf("Closing device \"mypci.\"\n"); return(err); } int mypci_read(dev_t dev, struct uio *uio, int ioflag) { int err = 0; uprintf("mypci read!\n"); return err; } int mypci_write(dev_t dev, struct uio *uio, int ioflag) { int err = 0; uprintf("mypci write!\n"); return(err); } /* PCI Support Functions */ /* * Return identification string if this is device is ours. */ static int mypci_probe(device_t dev) { uprintf("MyPCI Probe\n" "Vendor ID : 0x%x\n" "Device ID : 0x%x\n",pci_get_vendor(dev),pci_get_device(dev)); if (pci_get_vendor(dev) == 0x11c1) { uprintf("We've got the Winmodem, probe successful!\n"); return 0; } return ENXIO; } /* Attach function is only called if the probe is successful */ static int mypci_attach(device_t dev) { uprintf("MyPCI Attach for : deviceID : 0x%x\n",pci_get_vendor(dev)); sdev = make_dev(&mypci_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "mypci"); uprintf("Mypci device loaded.\n"); return ENXIO; } /* Detach device. */ static int mypci_detach(device_t dev) { uprintf("Mypci detach!\n"); return 0; } /* Called during system shutdown after sync. */ static int mypci_shutdown(device_t dev) { uprintf("Mypci shutdown!\n"); return 0; } /* * Device suspend routine. */ static int mypci_suspend(device_t dev) { uprintf("Mypci suspend!\n"); return 0; } /* * Device resume routine. */ static int mypci_resume(device_t dev) { uprintf("Mypci resume!\n"); return 0; } static device_method_t mypci_methods[] = { /* Device interface */ DEVMETHOD(device_probe, mypci_probe), DEVMETHOD(device_attach, mypci_attach), DEVMETHOD(device_detach, mypci_detach), DEVMETHOD(device_shutdown, mypci_shutdown), DEVMETHOD(device_suspend, mypci_suspend), DEVMETHOD(device_resume, mypci_resume), { 0, 0 } }; static driver_t mypci_driver = { "mypci", mypci_methods, 0, /* sizeof(struct mypci_softc), */ }; static devclass_t mypci_devclass; DRIVER_MODULE(mypci, pci, mypci_driver, mypci_devclass, 0, 0);
Дополнительная информация
PCI System Architecture, Fourth Edition by Tom Shanley, et al.