diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c
new file mode 100644
index 00000000..3b9750ed
--- /dev/null
+++ b/src/drivers/bus/pci.c
@@ -0,0 +1,144 @@
+#include "etherboot.h"
+#include "pci.h"
+
+#undef DBG
+#ifdef DEBUG_PCI
+#define DBG(...) printf ( __VA_ARGS__ )
+#else
+#define DBG(...)
+#endif
+
+
+/*
+ * Set device to be a busmaster in case BIOS neglected to do so.  Also
+ * adjust PCI latency timer to a reasonable value, 32.
+ */
+void adjust_pci_device ( struct pci_device *dev ) {
+	unsigned short	new_command, pci_command;
+	unsigned char	pci_latency;
+
+	pci_read_config_word ( dev, PCI_COMMAND, &pci_command );
+	new_command = pci_command | PCI_COMMAND_MASTER | PCI_COMMAND_IO;
+	if ( pci_command != new_command ) {
+		DBG ( "The PCI BIOS has not enabled this device!\n"
+		      "Updating PCI command %hX->%hX. bus %hhX dev_fn %hhX\n",
+		      pci_command, new_command, p->bus, p->devfn );
+		pci_write_config_word ( dev, PCI_COMMAND, new_command );
+	}
+	pci_read_config_byte ( dev, PCI_LATENCY_TIMER, &pci_latency);
+	if ( pci_latency < 32 ) {
+		DBG ( "PCI latency timer (CFLT) is unreasonably low at %d. "
+		      "Setting to 32 clocks.\n", pci_latency );
+		pci_write_config_byte ( dev, PCI_LATENCY_TIMER, 32);
+	}
+}
+
+/*
+ * Find the start of a pci resource.
+ */
+unsigned long pci_bar_start ( struct pci_device *dev, unsigned int index ) {
+	uint32_t lo, hi;
+	unsigned long bar;
+
+	pci_read_config_dword ( dev, index, &lo );
+	if ( lo & PCI_BASE_ADDRESS_SPACE_IO ) {
+		bar = lo & PCI_BASE_ADDRESS_IO_MASK;
+	} else {
+		bar = 0;
+		if ( ( lo & PCI_BASE_ADDRESS_MEM_TYPE_MASK ) ==
+		     PCI_BASE_ADDRESS_MEM_TYPE_64) {
+			pci_read_config_dword ( dev, index + 4, &hi );
+			if ( hi ) {
+#if ULONG_MAX > 0xffffffff
+					bar = hi;
+					bar <<= 32;
+#else
+					printf ( "Unhandled 64bit BAR\n" );
+					return -1UL;
+#endif
+			}
+		}
+		bar |= lo & PCI_BASE_ADDRESS_MEM_MASK;
+	}
+	return bar + pcibios_bus_base ( dev->bus );
+}
+
+/*
+ * Find the size of a pci resource.
+ */
+unsigned long pci_bar_size ( struct pci_device *dev, unsigned int bar ) {
+	uint32_t start, size;
+
+	/* Save the original bar */
+	pci_read_config_dword ( dev, bar, &start );
+	/* Compute which bits can be set */
+	pci_write_config_dword ( dev, bar, ~0 );
+	pci_read_config_dword ( dev, bar, &size );
+	/* Restore the original size */
+	pci_write_config_dword ( dev, bar, start );
+	/* Find the significant bits */
+	if ( start & PCI_BASE_ADDRESS_SPACE_IO ) {
+		size &= PCI_BASE_ADDRESS_IO_MASK;
+	} else {
+		size &= PCI_BASE_ADDRESS_MEM_MASK;
+	}
+	/* Find the lowest bit set */
+	size = size & ~( size - 1 );
+	return size;
+}
+
+/**
+ * pci_find_capability - query for devices' capabilities 
+ * @dev: PCI device to query
+ * @cap: capability code
+ *
+ * Tell if a device supports a given PCI capability.
+ * Returns the address of the requested capability structure within the
+ * device's PCI configuration space or 0 in case the device does not
+ * support it.  Possible values for @cap:
+ *
+ *  %PCI_CAP_ID_PM           Power Management 
+ *
+ *  %PCI_CAP_ID_AGP          Accelerated Graphics Port 
+ *
+ *  %PCI_CAP_ID_VPD          Vital Product Data 
+ *
+ *  %PCI_CAP_ID_SLOTID       Slot Identification 
+ *
+ *  %PCI_CAP_ID_MSI          Message Signalled Interrupts
+ *
+ *  %PCI_CAP_ID_CHSWP        CompactPCI HotSwap 
+ */
+int pci_find_capability ( struct pci_device *dev, int cap ) {
+	uint16_t status;
+	uint8_t pos, id;
+	uint8_t hdr_type;
+	int ttl = 48;
+
+	pci_read_config_word ( dev, PCI_STATUS, &status );
+	if ( ! ( status & PCI_STATUS_CAP_LIST ) )
+		return 0;
+
+	pci_read_config_byte ( dev, PCI_HEADER_TYPE, &hdr_type );
+	switch ( hdr_type & 0x7F ) {
+	case PCI_HEADER_TYPE_NORMAL:
+	case PCI_HEADER_TYPE_BRIDGE:
+	default:
+		pci_read_config_byte ( dev, PCI_CAPABILITY_LIST, &pos );
+		break;
+	case PCI_HEADER_TYPE_CARDBUS:
+		pci_read_config_byte ( dev, PCI_CB_CAPABILITY_LIST, &pos );
+		break;
+	}
+	while ( ttl-- && pos >= 0x40 ) {
+		pos &= ~3;
+		pci_read_config_byte ( dev, pos + PCI_CAP_LIST_ID, &id );
+		DBG ( "Capability: %d\n", id );
+		if ( id == 0xff )
+			break;
+		if ( id == cap )
+			return pos;
+		pci_read_config_byte ( dev, pos + PCI_CAP_LIST_NEXT, &pos );
+	}
+	return 0;
+}