diff -r 2d1d51615e0e src/arch/x86/bios/IntelMP.py
--- a/src/arch/x86/bios/IntelMP.py	Tue Nov 03 12:17:58 2015 -0600
+++ b/src/arch/x86/bios/IntelMP.py	Wed Nov 04 14:50:24 2015 +0000
@@ -108,25 +108,25 @@ class X86IntelMPProcessor(X86IntelMPBase
 
     feature_flags = Param.UInt32(0, 'flags returned by the CPUID instruction')
 
 class X86IntelMPBus(X86IntelMPBaseConfigEntry):
     type = 'X86IntelMPBus'
     cxx_class = 'X86ISA::IntelMP::Bus'
     cxx_header = 'arch/x86/bios/intelmp.hh'
 
     bus_id = Param.UInt8(0, 'bus id assigned by the bios')
     bus_type = Param.String("", 'string that identify the bus type')
-    # Legal values for bus_type are:
+    # Legal values for bus_type are [space padded to 6 bytes]:
     #
-    # "CBUS", "CBUSII", "EISA", "FUTURE", "INTERN", "ISA", "MBI", "MBII",
-    # "MCA", "MPI", "MPSA", "NUBUS", "PCI", "PCMCIA", "TC", "VL", "VME",
-    # "XPRESS"
+    # "CBUS  ", "CBUSII", "EISA  ", "FUTURE", "INTERN", "ISA   ", "MBI   ",
+    # "MBII  ", "MCA   ", "MPI   ", "MPSA  ", "NUBUS ", "PCI   ", "PCMCIA",
+    # "TC    ", "VL    ", "VME   ", "XPRESS"
 
 class X86IntelMPIOAPIC(X86IntelMPBaseConfigEntry):
     type = 'X86IntelMPIOAPIC'
     cxx_class = 'X86ISA::IntelMP::IOAPIC'
     cxx_header = 'arch/x86/bios/intelmp.hh'
 
     id = Param.UInt8(0, 'id of this APIC')
     version = Param.UInt8(0, 'bits 0-7 of the version register')
 
     enable = Param.Bool(True, 'if this APIC is usable')
diff -r 2d1d51615e0e configs/common/FSConfig.py
--- a/configs/common/FSConfig.py	Tue Nov 03 12:17:58 2015 -0600
+++ b/configs/common/FSConfig.py	Wed Nov 04 14:02:06 2015 +0000
@@ -503,63 +503,63 @@ def makeX86System(mem_mode, numCPUs=1, m
     disk0 = CowIdeDisk(driveID='master')
     disk2 = CowIdeDisk(driveID='master')
     disk0.childImage(mdesc.disk())
     disk2.childImage(disk('linux-bigswap2.img'))
     self.pc.south_bridge.ide.disks = [disk0, disk2]
 
     # Add in a Bios information structure.
     structures = [X86SMBiosBiosInformation()]
     self.smbios_table.structures = structures
 
     # Set up the Intel MP table
     base_entries = []
     ext_entries = []
     for i in xrange(numCPUs):
         bp = X86IntelMPProcessor(
                 local_apic_id = i,
                 local_apic_version = 0x14,
                 enable = True,
                 bootstrap = (i == 0))
         base_entries.append(bp)
     io_apic = X86IntelMPIOAPIC(
             id = numCPUs,
             version = 0x11,
             enable = True,
             address = 0xfec00000)
     self.pc.south_bridge.io_apic.apic_id = io_apic.id
     base_entries.append(io_apic)
     # In gem5 Pc::calcPciConfigAddr(), it required "assert(bus==0)",
     # but linux kernel cannot config PCI device if it was not connected to PCI bus,
     # so we fix PCI bus id to 0, and ISA bus id to 1.
-    pci_bus = X86IntelMPBus(bus_id = 0, bus_type='PCI')
+    pci_bus = X86IntelMPBus(bus_id = 0, bus_type='PCI   ')
     base_entries.append(pci_bus)
-    isa_bus = X86IntelMPBus(bus_id = 1, bus_type='ISA')
+    isa_bus = X86IntelMPBus(bus_id = 1, bus_type='ISA   ')
     base_entries.append(isa_bus)
     connect_busses = X86IntelMPBusHierarchy(bus_id=1,
             subtractive_decode=True, parent_bus=0)
     ext_entries.append(connect_busses)
     pci_dev4_inta = X86IntelMPIOIntAssignment(
             interrupt_type = 'INT',
             polarity = 'ConformPolarity',
             trigger = 'ConformTrigger',
             source_bus_id = 0,
             source_bus_irq = 0 + (4 << 2),
             dest_io_apic_id = io_apic.id,
             dest_io_apic_intin = 16)
     base_entries.append(pci_dev4_inta)
     def assignISAInt(irq, apicPin):
         assign_8259_to_apic = X86IntelMPIOIntAssignment(
                 interrupt_type = 'ExtInt',
                 polarity = 'ConformPolarity',
                 trigger = 'ConformTrigger',
                 source_bus_id = 1,
                 source_bus_irq = irq,
                 dest_io_apic_id = io_apic.id,
                 dest_io_apic_intin = 0)
         base_entries.append(assign_8259_to_apic)
         assign_to_apic = X86IntelMPIOIntAssignment(
                 interrupt_type = 'INT',
                 polarity = 'ConformPolarity',
                 trigger = 'ConformTrigger',
                 source_bus_id = 1,
                 source_bus_irq = irq,
                 dest_io_apic_id = io_apic.id,