diff -r 4bafb394707a sys/src/9/pc/devpccard.c
--- a/sys/src/9/pc/devpccard.c	Sun Feb 28 13:31:49 2021 +0100
+++ b/sys/src/9/pc/devpccard.c	Sun Feb 28 17:49:51 2021 +0100
@@ -520,7 +520,6 @@
 	static int initialized;
 	Pcidev *pci;
 	int i;
-	uchar intl;
 	char *p;
 
 	if (initialized)
@@ -539,9 +538,9 @@
 
 	/* Find all CardBus controllers */
 	pci = nil;
-	intl = 0xff;
 	while ((pci = pcimatch(pci, 0, 0)) != nil) {
 		uvlong baddr;
+		int size;
 		Cardbus *cb;
 		uchar pin;
 
@@ -633,23 +632,20 @@
 			pcicfgw8(cb->pci, 0xD4, 0xCA);
 		}
 
-		baddr = pcicfgr32(cb->pci, PciBAR0);
-		if (baddr == 0) {
-			int size = (pci->did == Ricoh_478_did)? 0x10000: 0x1000;
+		size = (pci->did == Ricoh_478_did)? 0x10000: 0x1000;
+		baddr = (ulong)pcicfgr32(cb->pci, PciBAR0);
+		if (baddr == 0 || upaalloc(baddr, size, 0) == -1) {
 			baddr = upaalloc(-1ULL, size, size);
 			if(baddr == -1)
 				continue;
 			pcicfgw32(cb->pci, PciBAR0, (ulong)baddr);
-			cb->regs = (ulong *)vmap(baddr, size);
 		}
-		else
-			cb->regs = (ulong *)vmap(baddr, 4096);
+		cb->regs = (ulong *)vmap(baddr, size);
 		if(cb->regs == nil)
 			continue;
 		cb->state = SlotEmpty;
 
-		if (intl != 0xff && intl != pci->intl)
-			intrenable(pci->intl, cbinterrupt, cb, pci->tbdf, "cardbus");
+		intrenable(pci->intl, cbinterrupt, cb, pci->tbdf, "cardbus");
 
 		/* Don't really know what to do with this... */
 		i82365probe(cb, LegacyAddr, LegacyAddr + 1);
@@ -778,9 +774,8 @@
 configure(Cardbus *cb)
 {
 	int i, r;
-	Pcidev *pci;
-	uvlong romlen, memlen, membase, rombase, bar;
-	ulong iobase, iolen, size;
+	ulong iobase, iolen;
+	uvlong membase, memlen;
 
 	if(DEBUG)
 		print("configuring slot %ld (%s)\n", cb - cbslots, states[cb->state]);
@@ -796,23 +791,10 @@
 	}
 
 	/* Scan the CardBus for new PCI devices */
-	pciscan(pcicfgr8(cb->pci, PciSBN), &cb->pci->bridge);
+	pciscan(pcicfgr8(cb->pci, PciSBN), &cb->pci->bridge, cp->pci);
 
-	/*
-	 * size the devices on the bus, reserve a minimum for devices arriving later,
-	 * allow for ROM space, allocate space, and set the cardbus mapping registers
-	 */
-	pcibussize(cb->pci->bridge, &memlen, &iolen);	/* TO DO: need initial alignments */
-
-	romlen = 0;
-	for(pci = cb->pci->bridge; pci != nil; pci = pci->list){
-		size = pcibarsize(pci, PciEBAR0);
-		if(size > 0){
-			pci->rom.bar = -1;
-			pci->rom.size = size;
-			romlen += size;
-		}
-	}
+	/* size the devices on the bus, reserve a minimum for devices arriving later */
+	pcibussize(cb->pci->bridge, &memlen, &iolen);
 
 	if(iolen < 512)
 		iolen = 512;
@@ -820,8 +802,6 @@
 	if(iobase == -1)
 		return;
 
-	rombase = memlen;
-	memlen += romlen;
 	if(memlen < 1*1024*1024)
 		memlen = 1*1024*1024;
 	membase = upaalloc(-1ULL, memlen, 4*1024*1024);	/* TO DO: better alignment */
@@ -832,68 +812,20 @@
 	pcicfgw32(cb->pci, PciCBILR0, iobase + iolen-1);
 	pcicfgw32(cb->pci, PciCBIBR1, 0);
 	pcicfgw32(cb->pci, PciCBILR1, 0);
+	cb->pci->ioa.bar = iobase;
+	cp->pci->ioa.siz = iolen;
 
 	pcicfgw32(cb->pci, PciCBMBR0, (ulong)membase);
 	pcicfgw32(cb->pci, PciCBMLR0, (ulong)membase + memlen-1);
 	pcicfgw32(cb->pci, PciCBMBR1, 0);
 	pcicfgw32(cb->pci, PciCBMLR1, 0);
+	cp->pci->mema.bar = membase;
+	cb->pci->mema.siz = memlen;
 
-//	pcibussize(cb->pci->bridge, &membase, &iobase);	/* now assign them */
-	rombase += membase;
+	/* Route interrupts to INTA#/B# */
+	pcicfgw16(cb->pci, PciBCR, pcicfgr16(cb->pci, PciBCR) & ~(1 << 7));
 
-	for(pci = cb->pci->bridge; pci != nil; pci = pci->list){
-		r = pcicfgr16(pci, PciPCR);
-		r &= ~(PciPCR_IO|PciPCR_MEM);
-		pcicfgw16(pci, PciPCR, r);
-
-		/*
-		 * Treat the found device as an ordinary PCI card.
-		 * It seems that the CIS is not always present in
-		 * CardBus cards.
-		 * XXX, need to support multifunction cards
-		 */
-		for(i = 0; i < Nbars; i++) {
-			if(pci->mem[i].size == 0)
-				continue;
-			bar = pci->mem[i].bar;
-			if(bar & 1)
-				bar += iobase;
-			else
-				bar += membase;
-			pci->mem[i].bar = bar;
-			pcicfgw32(pci, PciBAR0 + 4*i, bar);
-			if((bar & 1) == 0){
-				print("%T mem[%d] %8.8llux %d\n", pci->tbdf, i, bar, pci->mem[i].size);
-				if(bar & 0x80){	/* TO DO: enable prefetch */
-					;
-				}
-			}
-		}
-		if((size = pcibarsize(pci, PciEBAR0)) > 0) {	/* TO DO: can this be done by pci.c? */
-			pci->rom.bar = rombase;
-			pci->rom.size = size;
-			rombase += size;
-			pcicfgw32(pci, PciEBAR0, pci->rom.bar);
-		}
-
-		/* Set the basic PCI registers for the device */
-		pci->pcr = pcicfgr16(pci, PciPCR);
-		pci->pcr |= PciPCR_IO|PciPCR_MEM|PciPCR_Master;
-		pci->cls = 8;
-		pci->ltr = 64;
-		pcicfgw16(pci, PciPCR, pci->pcr);
-		pcicfgw8(pci, PciCLS, pci->cls);
-		pcicfgw8(pci, PciLTR, pci->ltr);
-
-		if (pcicfgr8(pci, PciINTP)) {
-			pci->intl = pcicfgr8(cb->pci, PciINTL);
-			pcicfgw8(pci, PciINTL, pci->intl);
-
-			/* Route interrupts to INTA#/B# */
-			pcicfgw16(cb->pci, PciBCR,
-					  pcicfgr16(cb->pci, PciBCR) & ~(1 << 7));
-		}
-	}
+	pcibusmap(cb->pci->bridge, &membase, &iobase, 1);
 }
 
 static void
diff -r 4bafb394707a sys/src/9/pc/mp.c
--- a/sys/src/9/pc/mp.c	Sun Feb 28 13:31:49 2021 +0100
+++ b/sys/src/9/pc/mp.c	Sun Feb 28 17:49:51 2021 +0100
@@ -351,13 +351,19 @@
 
 	if(bus == nil){
 		/*
-		 * if the PCI device is behind a PCI-PCI bridge thats not described
-		 * by the MP or ACPI tables then walk up the bus translating interrupt
-		 * pin to parent bus.
+		 * if the PCI device is behind a bridge thats not described
+		 * by the MP or ACPI tables then walk up the bus translating
+		 * interrupt pin to parent bus.
 		 */
 		if(pci != nil && pci->parent != nil && pin > 0){
-			pin = ((dno+(pin-1))%4)+1;
 			pci = pci->parent;
+			if(pci->ccrb == 6 && pci->ccru == 7){
+				/* Cardbus bridge, use controllers interrupt pin */
+				pin = pcicfgr8(pci, PciINTP);
+			} else {
+				/* PCI-PCI bridge */
+				pin = ((dno+(pin-1))%4)+1;
+			}
 			bno = BUSBNO(pci->tbdf);
 			dno = BUSDNO(pci->tbdf);
 			goto Findbus;
diff -r 4bafb394707a sys/src/9/pc/pcipc.c
--- a/sys/src/9/pc/pcipc.c	Sun Feb 28 13:31:49 2021 +0100
+++ b/sys/src/9/pc/pcipc.c	Sun Feb 28 17:49:51 2021 +0100
@@ -688,7 +688,7 @@
 	list = &pciroot;
 	for(bno = 0; bno <= pcimaxbno; bno++) {
 		int sbno = bno;
-		bno = pciscan(bno, list);
+		bno = pciscan(bno, list, nil);
 
 		while(*list)
 			list = &(*list)->link;
diff -r 4bafb394707a sys/src/9/port/pci.c
--- a/sys/src/9/port/pci.c	Sun Feb 28 13:31:49 2021 +0100
+++ b/sys/src/9/port/pci.c	Sun Feb 28 17:49:51 2021 +0100
@@ -643,9 +643,9 @@
 }
 
 int
-pciscan(int bno, Pcidev **list)
+pciscan(int bno, Pcidev **list, Pcidev *parent)
 {
-	return pcilscan(bno, list, nil);
+	return pcilscan(bno, list, parent);
 }
 
 void
diff -r 4bafb394707a sys/src/9/port/pci.h
--- a/sys/src/9/port/pci.h	Sun Feb 28 13:31:49 2021 +0100
+++ b/sys/src/9/port/pci.h	Sun Feb 28 17:49:51 2021 +0100
@@ -228,7 +228,7 @@
 extern int pcicfgr8(Pcidev* pcidev, int rno);
 extern void pcicfgw8(Pcidev* pcidev, int rno, int data);
 
-extern int pciscan(int bno, Pcidev **list);
+extern int pciscan(int bno, Pcidev **list, Pcidev *parent);
 extern void pcibusmap(Pcidev *root, uvlong *pmema, ulong *pioa, int wrreg);
 extern void pcibussize(Pcidev *root, uvlong *msize, ulong *iosize);