boot_config(8)          OpenBSD System Manager's Manual         boot_config(8)

NAME
     boot_config - how to change kernel configuration at boot



DESCRIPTION
     BOOT_CONFIG is a kernel option that make it possible to change the con-
     figuration at boot time.

     The boot time configuration is invokes by a -c option when OpenBSD ask
     for kernel to boot.

     >> OpenBSD BOOT 640/31744 k [1.29]
     use ? for file list, or carriage return for defaults
     use hd(1,a)/bsd to boot sd0 when sd0 is also installed
     Boot: [[[wd(0,a)]/bsd][-abcdrs]] : -c\n
     Booting.. blah blah blah
     avail mem = 28188672
     using 430 buffers containing 1761280 bytes of memory
     User Kernel Config
     UKC>

COMMANDS
     add dev            Add a device through copying another.

     base 8|10|16       Change the base for large numbers. E.g. I/O addresses
                        in a VAXen are octal.

     change devno|dev   Modify one or more devices.

     disable devno|dev  Disable one or more devices.

     enable devno|dev   Enable one or more devices.

     exit               Continue boot.

     find devno|dev     Find one or more devices.

     help               Give a short summary of all commands and its argu-
                        ments.

     list               Show all known devices a screen at the time.

     lines [count]      Setup the number of rows per page.

     quit               Continue boot.

     show [attr [val]]  Show devices with an attribute and optional with a
                        specified value.

EXAMPLES
     Your ethernet card isn't found at boot because the configuration don't
     match the hardware. E.g. wrong IRQ in OpenBSD/i386. You know that your
     ethernet card is using the eddriver.

     UKC> find ed\n
     81 ed0 at isa0 port 0x280 size 0 iomem 0xd0000 iosiz 0 irq 9 drq -1 pnpid -1
     82 ed1 at isa0 port 0x250 size 0 iomem 0xd8000 iosiz 0 irq 9 drq -1 pnpid -1
     83 ed2 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq 10 drq -1 pnpid -1
     84 ed* at pcmcia0 port 0x300 size 0x20 iomem -1 iosiz 0 irq 10 drq -1 slot -1
     UKC>

     Ok, ed2 seems to match the configuration except IRQ 5 instead of IRQ 10.
     So change irq on ed2 with the change command. Specify device by name or
     number.

     UKC> change ed2\n
     83 E ed2 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq 10 drq -1 pnpid -1
     change (y/n) ? y\n
     port [0x300] ? \n
     size [0] ? \n
     iomem [0xcc000] ? \n
     iosiz [0] ? \n
     irq [10] ? 5\n
     drq [-1] ? \n
     pnpid [-1] ? \n
     83 ed2 changed
     83 ed2 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq 5 drq -1 pnpid -1
     UKC>

     Another case is when a none existing device is wrongly found when another
     device is found at the probed location. One known case is the Mitsumi
     none ATAPI cdrom in OpenBSD/i386. The simplest thing to solve that prob-
     lem is to disable mcd0.

     UKC> find mcd0\n
      29 mcd0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 pnpid -1
     UKC> disable mcd0\n
      29 mcd0 disabled
     UKC> find 29\n
      29 mcd0 at isa0 disable port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 pnpid -1

     The show command is useful for finding which devices has a certain at-
     tribute.  It can even show us all devices with an certain value of the
     attribute.

     UKC> show slot\n
       1 ahc* at eisa0 slot -1
       3 ep0 at eisa0 slot -1
       6 ep* at eisa0 slot -1
       8 ep* at pcmcia* port 0x300 size 0x10 iomem -1 iosiz 0 irq 10 drq -1 slot -1
      40 com3 at pcmcia* port 0x2e8 size 8 iomem -1 iosiz 0 irq 3 drq -1 slot -1
      84 ed* at pcmcia* port 0x300 size 0x20 iomem -1 iosiz 0 irq 10 drq -1 slot -1
      86 ahb* at eisa0 slot -1
      87 fea* at eisa0 slot -1
     UKC> show port 0x300\n
       8 ep* at pcmcia* port 0x300 size 0x10 iomem -1 iosiz 0 irq 10 drq -1 slot -1
      29 mcd0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 pnpid -1
      31 wt0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 5 drq 1 pnpid -1
      58 el0 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 9 drq -1 pnpid -1
      60 ie1 at isa0 port 0x300 size 0 iomem -1 iosiz 0 irq 10 drq -1 pnpid -1
      83 ed2 at isa0 port 0x300 size 0 iomem 0xcc000 iosiz 0 irq 10 drq -1 pnpid -1
      84 ed* at pcmcia* port 0x300 size 0x20 iomem -1 iosiz 0 irq 10 drq -1 slot -1
     UKC>

     It is possible to add devices, but only devices that already exists in
     the kernel. If a device is added all devices after is renumbered.

     UKC> find ep\n
       2 ep0 at isa0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 pnpid -1
       3 ep0 at eisa0 slot -1
       4 ep0 at pci0|pci* dev -1 function -1
       5 ep* at isa0 port -1 size 0 iomem -1 iosiz 0 irq -1 drq -1 pnpid -1
       6 ep* at eisa0 slot -1
       7 ep* at pci0|pci* dev -1 function -1
       8 ep* at pcmcia* port 0x300 size 0x10 iomem -1 iosiz 0 irq 10 drq -1 slot -1
     UKC> add ep1\n
     Clone Device (DevNo, 'q' or '?') ? 4
     Insert before Device (DevNo, 'q' or '?') ? 5
       5 ep1 at pci0|pci* dev -1 function -1
     UKC> change 5\n
       5 ep1 at pci0|pci* dev -1 function -1
     change (y/n) ?\n
     dev [-1] ? 14\n
     function [-1] ? \n
       5 ep1 changed
       5 ep1 at pci0|pci* dev 14 function -1
     UKC>

     And to continuing boot try quit or exit...

     UKC> quit\n
     Continuing...
     mainbus0 (root)

BUGS
     The add command is rather restricted. Might be fixed in the future.

AUTHOR
     Mats O Jansson <moj@stacken.kth.se>

4th Berkeley Distribution     September 21, 1996                             3