a smart port card tutorial --- software john dehart washington university [email protected]

January 10,11 2000 Kits Workshop 1WashingtonWASHINGTON UNIVERSITY IN ST LOUIS

A Smart Port Card

Tutorial---

Software

John DeHartWashington University

[email protected]://www.arl.wustl.edu/~jdd


Software Overview

• SPC Specific Kernel Modifications• Building a Kernel

– config

– compile

• Loading Kernel onto SPC to execute it– download via APIC

• Initiating Kernel execution– boot loader

• Configuring Devices– APIC


SPC Kernel Modifications

• Kernel Configuration File:– Memory Disk

– Serial Console

– Most device drivers unneeded (e.g no Ethernet…)

• Source Code Changes:– PCI Device Configuration: ./dev/pci/if_apic_pci.c

• APIC Specific configuration handled by driver

– Change some APIC defaults: ./dev/ic/apic.c• made switch port the default

– No HLT instruction: locore.s

– Kernel Memory Page Allocation: • ./arch/i386/include/pmap.new.h

– RTC: ./arch/i386/isa/clock.c, ./ufs/ffs/ffs_vfsops.c• We still had to remove some RTC code...


Steps to an Executing Kernel on an SPC

• Configure Kernel– Start with a typical NetBSD kernel config file

– Add SPC specific option:• options SPC

– add memory disk (filesystem will reside in kernel!)• options MEMORY_DISK*

• options MINIROOTSIZE

– serial console port• options CONSDEVNAME

• options CONS_OVERRIDE

– remove “extra” devices (Ethernet, mouse, …)


Steps to an Executing Kernel on an SPC

• Filesystem– we use a vnode disk device: vnd(4)

• disk device in a regular file

• pseudo-device vnd– must be included in your kernel where you are building the FS

– Does NOT need to be included in your kernel for the SPC

– build filesystem• dd(1): create the file

• vnconfig(8) - configure vnode pseudo disk as a regular file

• disklabel(8) - label it

• newfs(8) - construct a new file system

• mount(8)/umount(8): mount/unmount filesystem

– mknod(8) - make device files

– populate regular files from an existing system


… Steps to an Executing Kernel on an SPC

• Compile Kernel• Make a symbol only version of kernel for /netbsd

– ps, netstat, … use symbols from /netbsd

– real kernel with file system CANNOT reside in itself!

• Add File System to Kernel– mdsetimage(8)

• Create an image version of Kernel– sets up bss section and symbol table

• Kernel bss file is ready to download!


… Steps to an Executing Kernel on an SPC

• Reset SPC• Download Boot Loader

– via APIC control cells – loaded at physical memory location: 0x0

• Flip bit at location 0xFFE00 to start boot loader– configure NorthBridge (before kernel download!!)

• cache, memory size, memory type, timing, etc

– wait for kernel download to complete• looks for location 0x3FC to change from 0 to 1

– set up parameters on stack and jump to kernel• kernel located at 0x100000

• Download kernel bss file• Flip bit at location 0x3FC - kernel starts booting...


The Download Process

0x0 Bootloader

0x0100000Kernel

0 0 0 0 0 0 0 0

0x0FFE00

0x03FC

Boot ROM0xFFFFFFF0

0 0 0 0 0 0 0 1

0 0 0 0 0 0 0 00 0 0 0 0 0 0 1

RESET

DownloadProgram


Host APIC to SPC Control Connections

APIC

PC

WUGS Switch

Port 0Port 1

Port 7

Port 6

Port 3Port 5

SPC/Port 4

Port 2

0/42

0/41

0/33 (0x21)

0/0x0321APIC ID

41 0x0321

Example


APIC Driver at SPC Boot Time

• PCI Configuration Space (sys/dev/pci/if_apic_pci.c):

– Base memory address:• APIC Physical memory in SPC starts at 0xF0000000

– Memory mapping options:• Memory Enable• Master Enable• Write Invalidate Enable

– IRQ• Driver normally would read this from PCI config space• APIC statically assigned IRQ 5 by System FPGA• For consistency, driver writes 5 to Interrupt Line Register


PCI Configuration Space

Configuration Space Header

Device ID Vendor IDStatus Command

Class Code Revision ID

BIST HeaderType

Cardbus CIS PointerSubsystem ID Subsystem Vendor ID

Expansion ROM Base AddressReservedReserved

Max_Lat Min_Gnt

LatencyTimer

Cache LineSize

Base Address Registers

InterruptPin

InterruptLine


Defining a Route on APIC Network Interface• Configure the APIC

> ifconfig apic0 inet 192.168.10.1 netmask 0xffffff00- network interface: apic0- our IP address: 192.168.10.1

• Configure a VCI> atm_ifconfig apic0 0xc5 open -aal5 -llc -besteffort

-maxqueuebufs 100 -inport 0 -outports 1- network interface: apic0- vci: 0xc5- besteffort (vs. paced or lowdelay)- Tx buffer queue limit for this VCI: ‘maxqueuebufs 100’

• Configure the route> route add -iface 192.168.10.5 -link apic0:0.0.0.c5

- destination: 192.168.10.5- network interface: apic0- vci: 0xc5


atm_ifconfig> atm_ifconfigUsage: atm_ifconfig <interface> <vpivci> [open|close|modify|getall [options...]]

Options are:

-aal0 | -aal5

-llc | -nollc <protocol>: use LLC/SNAP?

protocol is inet | ratm | value of ethernet type

-loopback

-inport <input_port_number>

-outports <bitvector_of_output_ports>

bitvector: 1 => port 0, 2 => port 1, 3 => both

-lowdelay | -paced <rate> | -besteffort

-maxqueuebufs <max_descriptors_in_tx_queue>

<rate> is in Kbits/sec


IPP

OP

P

SPC

TI

Switch Fabric

IPP

OP

P

SPC

TI

IPP

OP

P

TI

ControlProcessor

APIC Configuration

6 56 5 6 5

IPP

OP

P

SPC

TI

IPP

OP

P

SPC

TI

. . .

Sys.FPGA

32-64MB

Pentium

Cache

NorthBridgeAPIC

33 3 66 6

SPC


IPP

OP

P

TI

Sys.FPGA

32-64MB

Pentium

Cache

NorthBridgeAPIC

Inp

ort

1

Fiber

Ou

tpo

rt 2

Ou

tpo

rt 1

Inp

ort

0

Defining APIC Ports for Routing

atm_ifconfig apic0 0xca open -aal5 -llc -besteffort -inport $INPORT -outports $OUTPORTs

SwitchINPORT OUTPORTs

0 1

0 2

1 1

1 2

0 3

1 3


Caveats

• You cannot change the IRQ assignments:– They are fixed in the System FPGA

– And there should be no reason to change them

• HLT instruction in locore.s commented out• PCI bus may be 25MHz or 33 MHz

– Adjustment of NetBSD clock may be needed

• Memory/Filesystem tradeoffs– we have not pushed the limits yet

• Understand APIC port numbering• SPC needs to be reset before EACH download

a smart port card tutorial --- software john dehart washington university [email protected]

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