/* $NetBSD: README,v 1.3 2007/10/17 19:56:54 garbled Exp $ */ Overview This is a port to the Motorola "SandPoint" evaluation system. The SandPoint is the successor to the "Yellowknife" system. The system can be fitted with different PMCs (Processor Mezzanine Cards). This port is specifically for the rev X2 motherboard system with the PPC 8240 PMC rev X4 installed. It also works with the Altimus X2 PMC (MPC7400 with MPC107). All references (cf) listed here are for the MPC8240 Integrated Processor User's Manual. Information on the Sandpoint can be found on Motorola's web site: http://www.mot.com/SPS/PowerPC/teksupport/refdesigns/sandpoint.html SandPoint Hardware Configuration This port was developed on a Sandpoint X2 motherboard with a Unity X4 PMC. This port assumes that the jumpers are set as follows: S3/S4 - Mode 1: PMC w/o IDE (switches opposite, one nearest PCI slot toward near edge) S5 - Interrupt to PMC normal (switch toward near edge) S6 - Local I/O shared with slot 2 (switch toward near edge) Mode 0 (PMC w/ IDE) does not appear to work right with ISA interrupts. The interrupts from the Winbond chip do not appear at the PMC. On the PPMC, we assume a 100MHz clock. on PPMC: (C == closed, or "on") SW2: C ROM on PCI bus (DINK32 on mainboard) - Map "B": CHRP C Motorola PPMC C Wait for initialization (peripheral mode) - Program mode: Normal mode - Select normal ROM - 33 MHz only - COP only resets local CPU/MPC107 SW3: -C--C PCI 33, Mem 66, PPC 266 -- 0.5 - 0.9 ns PCI hold time C 25 ohm PCI drive strength Address Map For this port, we choose the "Address Map B" (CHRP-compatible) for the system (see SW2, #2, above): (Processor View) 0000 0000 0009 FFFF System Memory 000A 0000 000F FFFF Compatibility Hole (programmable to go to PCI space or system memory--programmed for system memory--cf 5.8) 0010 0000 3FFF FFFF System memory 4000 0000 7FFF FFFF Reserved (programmed to give a memory select error if accessed--cf 5.7.2) 8000 0000 FCFF FFFF PCI memory space FD00 0000 FDFF FFFF PCI/ISA memory space (see 5.8, CPU_FD_ALIAS_EN) FE00 0000 FE7F FFFF PCI/ISA I/O space (Forwarded to PCI address space with high byte zeroed, but FE01 0000 and up are reserved) FE80 0000 FEBF FFFF PCI I/O space (Forwarded to PCI I/O space with high byte zeroed) FEC0 0000 FEDF FFFF PCI configuration address register (Each word in this range is aliased to the PCI CONFIG_ADDR register) FEE0 0000 FEEF FFFF PCI configuration data register (Each word in this range is aliased to the PCI CONFIG_DATA register) FEF0 0000 FEFF FFFF PCI interrupt acknowledge FF00 0000 FF7F FFFF 32- or 64-bit Flash/ROM space (Can hit either local memory or PCI bus -- cf. 5.6) FF80 0000 FFFF FFFF 8-, 32- or 64-bit Flash/ROM space (Can hit either local memory or PCI bus -- cf. 5.6) This is a host-mode port, so the inbound and output translation windows are unused. The Embedded Utilities Memory Block (EUMB) is set to be 1M below the end of the PCI memory space: FC00 0000, so EUMBBAR is FC00 0000, giving us Message unit (I2O) base : FC00 0000 (cf. 10.2, 10.2.3, 10.3) DMA base : FC00 1000 (cf. 9.2) ATU base : FC00 2000 (cf. 4.3.3) I2C base : FC00 3000 (cf. 11.3) EPIC base : FC04 0000 (cf. 12.2) Boot Information The SandPoint ships with the Motorola DINK32 ROM. This is a rather basic ROM with only serial-download (S-Record) capability for loading the kernel. Basically, the kernel is loaded to a specified address and you jump to it. The ROM takes care of initializing the MICRs and MCCRs. There is really no boot information to pass. It would be nice to have a much more complete ROM interface, allowing settings for, say, bootp/tftp boot, automatic boot, and persistent settings (for console rate, auto boot, bootp, etc), and that might be provided at some point, but that's not available as of this writing. So, the kernel is hard-coded to boot w/ 32MB for now. Interrupt Configuration The 8240 has the internal EPIC. For the SandPoint, the EPIC is programmed in mixed-mode (GCR) with direct interrupts (EICR). With this configuration, there are 13 available interrupts: 4 global timers 5 direct IRQs IRQ0 - PCI Slot #0 INTA# IRQ1 - PCI Slot #1 INTA# / shared with WinBond I/O IRQ2 - PCI Slot #2 INTA# IRQ3 - PCI Slot #3 INTA# IRQ4 - On-PPMC 16552 interrupt (Unity X2) IRQ4 - pulled down w/ resistor (Unity X4) 4 internal interrupts I2C DMA Ch0 DMA Ch1 I2O message unit The SandPoint can run in one of 4 interrupt modes: 0 - PMC host with IDE (3.3v PCI slots are unavailable) 1 - PMC host w/o IDE (all PCI slots are available) 2 - PMC agent, Winbond providing arbitration & interrupt to INTA# on PMC 3 - Yellowknife mode--just like #2, except drives INTA# on 4th PCI slot We choose to run in mode 1 as Motorola recommends modes 0 or 1 for all new development. Unfortunately, mode 0 does not appear to work--"ISA" interrupts are lost. In this mode, with interrupts routed to PCI slot 3, we have to check for both a Winbond (ISA) interrupt, and a PCI slot interrupt. So basically, we have a two-level interrupt configuration for Winbond interrupts. The ISA bus attachment registers an interrupt for PCI slot 3 with its own interrupt handler. Drivers for ISA devices on the Winbond will register interrupts with the ISA interrupt handler. The sticky part of this is how to deal with one global interrupt priority. SandPoint III "SP3" Interrupt Configuration With a help of additional logic circuit SP3 organizes external interrupt sources as EPIC serial mode interrupts. 16 serial IRQs IRQ0 - WinBond South bridge i8259 PIC, polarity inverted IRQ1 - reserved IRQ2 - PCI Slot #1, INTA# IRQ3 - PCI Slot #2, INTA# IRQ4 - PCI Slot #3, INTA# IRQ5 - PCI Slot #4, INTA# IRQ6 - WinBond INTA# IRQ7 - WinBond INTB# IRQ8 - WinBond INTC# IRQ9 - WinBond INTD# IRQ10 thru 15 - reserved SP3 provides switch selections to emulate SP1/2 compatible EPIC direct mode interrupt assignments.