svn commit: r327606 - head/stand/i386/libi386

[Sean Bruno]

Author: sbruno
Date: Fri Jan  5 23:50:50 2018
New Revision: 327606
URL: https://svnweb.freebsd.org/changeset/base/327606

Log:
  Handle misconfigured/nonexistent pcidev for comconsole instead of BTX panic.
  
  PR:		203319
  Reviewed by:	imp jhb
  MFC after:	2 weeks
  Sponsored by:	Limelight Networks
  Differential Revision:	https://reviews.freebsd.org/D13776

Modified:
  head/stand/i386/libi386/comconsole.c

Modified: head/stand/i386/libi386/comconsole.c
==============================================================================
--- head/stand/i386/libi386/comconsole.c	Fri Jan  5 23:21:47 2018	(r327605)
+++ head/stand/i386/libi386/comconsole.c	Fri Jan  5 23:50:50 2018	(r327606)
@@ -267,6 +267,16 @@ comc_pcidev_handle(uint32_t locator)
 		printf("Cannot read bar at 0x%x\n", locator);
 		return (CMD_ERROR);
 	}
+
+	/* 
+	 * biospci_read_config() sets port == 0xffffffff if the pcidev
+	 * isn't found on the bus.  Check for 0xffffffff and return to not
+	 * panic in BTX.
+	 */
+	if (port == 0xffffffff) {
+		printf("Cannot find specified pcidev\n");
+		return (CMD_ERROR);
+	}
 	if (!PCI_BAR_IO(port)) {
 		printf("Memory bar at 0x%x\n", locator);
 		return (CMD_ERROR);