A Smart Port Card Tutorial --- Software John DeHart Washington University jdd@arl.wustl

1. A Smart Port Card Tutorial --- Software John DeHart Washington University jdd@arl.wustl.edu http://www.arl.wustl.edu/~jdd

2. 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

3. 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...

4. 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, …)

5. 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

6. … 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!

7. … 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...

8. The Download Process 0x0 Bootloader RESET 0x03FC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Download Program 0x0FFE00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0x0100000 Kernel 0xFFFFFFF0 Boot ROM

9. WUGS Switch 41 0x0321 Port 1 Port 0 Port 7 Port 2 Port 6 PC Port 5 APIC Port 3 SPC/ Port 4 APIC ID Host APIC to SPC Control Connections Example 0/41 0/42 0/33 (0x21) 0/0x0321

10. 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

11. Device ID Vendor ID Status Command Class Code Revision ID BIST Header Type Latency Timer Cache Line Size Base Address Registers Cardbus CIS Pointer Subsystem ID Subsystem Vendor ID Expansion ROM Base Address Reserved Reserved Max_Lat Min_Gnt Interrupt Pin Interrupt Line PCI Configuration Space Configuration Space Header

12. 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

13. atm_ifconfig • atm_ifconfig Usage: 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

14. 6 6 5 5 6 5 IPP IPP IPP IPP OPP OPP OPP OPP IPP OPP Pentium Cache SPC SPC SPC SPC TI TI TI TI 3 3 3 6 6 6 APIC Configuration ControlProcessor Switch Fabric Sys.FPGA 32-64 MB APIC NorthBridge . . . SPC TI

15. Sys.FPGA 32-64 MB Inport 1 Outport 2 APIC NorthBridge IPP OPP Pentium Outport 1 Cache Inport 0 TI Fiber Defining APIC Ports for Routing atm_ifconfig apic0 0xca open -aal5 -llc -besteffort -inport $INPORT -outports $OUTPORTs Switch INPORT OUTPORTs 0 1 0 2 1 1 1 2 0 3 1 3

16. 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