PDC(4) | Device Drivers Manual (hppa) | PDC(4)

# NAME

`pdc` — Processor-Dependent Code firmware driver

# SYNOPSIS

`pdc0 at mainbus?`

# DESCRIPTION

The `pdc` driver provides system console services through the PDC and also a means for calling PDC procedures, described later. The PDC console is used early in the kernel startup before enough kernel subsystems have been initialized to directly use the hardware i.e. serial ports, keyboard, and video.

The PDC version displayed at system boot is relevant to the particular system model and is not necessarily comparable to PDC versions on other systems.

# PDC PROCEDURES

PDC procedure calls are all made through a single entry point and assume normal C language calling conventions, with option number in the first argument and the return data address in the second, unless indicated otherwise. Each call requires at most 7KB of the available stack. Here is the list of procedures and options descriptions:

`pdc`(PDC_ADD_VALID, PDC_ADD_VALID_DFLT, paddr)
  Perform a read operation attempt at the physical address paddr without causing a HPMC, in order to verify that the address is valid and there is a device to respond to it. The implementation may choose to call the caller's HPMC handler and raise error conditions on the bus converters.
`pdc`(PDC_ALLOC, PDC_ALLOC_DFLT, ptr, size)
  Allocate static storage for IODC use of size bytes and return the address in a word pointed to by the ptr argument. There is no way of freeing the storage allocated and thus care shall be taken to not exhaust the total allocation limit of 32KB.
`pdc`(PDC_BLOCK_TLB, PDC_BTLB_DEFAULT, ptr)
  Get block TLB parameters into the data area pointed to by the ptr argument. This includes minimal and maximal entry size and number of fixed and variable sized entries in the block TLB. Fixed entries have size of power of two and are aligned to the size where variable entries can have any size and base address both aligned to a page.
`pdc`(PDC_BLOCK_TLB, PDC_BTLB_INSERT, sp, va, pa, len, acc, slot);
  Insert block TLB entry specified by the space ID sp, virtual address va, physical address pa, region length len, access rights acc, into the slot number slot.
`pdc`(PDC_BLOCK_TLB, PDC_BTLB_PURGE, sp, va, slot, len)
  Purge one entry from the block TLB specified by the space ID sp, virtual address va, region length len, from slot number slot.
`pdc`(PDC_BLOCK_TLB, PDC_BTLB_PURGE_ALL)
  Purge all entries from the block TLB.
`pdc`(PDC_CACHE, PDC_CACHE_DFLT, ptr)
  Retrieve cache and TLB configuration parameters into the data area pointed to by the ptr argument. The format of the data stores is as follows:

  addr | contents
  0x00 | I-cache size in bytes
  0x04 | I-cache configuration
  0x08 | I-cache base for flushing
  0x0c | I-cache stride for flushing
  0x10 | I-cache count for flushing
  0x14 | I-cache loop size for flushing
  0x18 | D-cache size in bytes
  0x1c | D-cache configuration
  0x20 | D-cache base for flushing
  0x24 | D-cache stride for flushing
  0x28 | D-cache count for flushing
  0x2c | D-cache loop size for flushing
  0x30 | ITLB size
  0x34 | ITLB configuration
  0x38 | ITLB space base for flushing
  0x3c | ITLB space stride for flushing
  0x40 | ITLB space count for flushing
  0x44 | ITLB address base for flushing
  0x48 | ITLB address stride for flushing
  0x4c | ITLB address count for flushing
  0x50 | ITLB loop size for flushing
  0x54 | DTLB size
  0x58 | DTLB configuration
  0x5c | DTLB space base for flushing
  0x60 | DTLB space stride for flushing
  0x64 | DTLB space count for flushing
  0x68 | DTLB address base for flushing
  0x6c | DTLB address stride for flushing
  0x70 | DTLB address count for flushing
  0x74 | DTLB loop size for flushing

  The cache configuration word is formatted as follows:

  bit | len | contents
  0 | 12 | reserved
  13 | 3 | set 1 if coherent operation supported
  16 | 2 | flush mode: 0 — fdc & fic; 1 — fdc; 2 — fic; 3 — either
  18 | 1 | write-thru D-cache if set
  19 | 2 | reserved
  21 | 3 | cache line size
  24 | 4 | associativity
  28 | 4 | virtual address alias boundary

`pdc`(PDC_CACHE, PDC_CACHE_SETCS, ptr, i_cst, d_cst, it_cst, dt_cst)
  The second word in each of the i_cst, d_cst, it_cst, and dt_cst arguments specifies the desired coherency operation for the instructions cache, data cache, instructions TLB, and data TLB, respectively. The data area pointed to by the ptr argument receives the actual coherent operation state after an attempted change. The CPU does not support the requested operation change should the corresponding words not match the arguments upon return. The currently supported values are zero for incoherent operation, and one for coherent operation.
`pdc`(PDC_CACHE, PDC_CACHE_GETSPIDB, ptr)
  The word pointed to by the ptr argument receives a mask of space ID used in hashing for cache tag.
`pdc`(PDC_CHASSIS, PDC_CHASSIS_DISP, display)
  Update the chassis display with data given in the display argument. The bitfields in the word are as follows:

  0xe0000
    Specifies the system state.
    0x00000
      off
    0x20000
      fault
    0x40000
      test
    0x60000
      initialize
    0x80000
      shutdown
    0xa0000
      warning
    0xc0000
      run
    0xe0000
      all on
  0x10000
    Blank the chassis display.
  0x0f000
    This and the other lower three nibbles specify the four hex digits to be displayed on the chassis display.
`pdc`(PDC_CHASSIS, PDC_CHASSIS_WARN, ptr)
  Return the warnings from the chassis fans, temperature sensors, batteries and power supplies. A word of data is returned in the area pointed by the ptr argument and is described with bitfields:

  0xff000000
    Zero means none of the redundant chassis components has indicated any failures. A non-zero value specifies the failing component.
  0x4
    Indicates the chassis battery charge is low.
  0x2
    The chassis temperature has exceeded the low threshold.
  0x1
    The chassis temperature has exceeded the middle threshold.
`pdc`(PDC_CHASSIS, PDC_CHASSIS_ALL, ptr, display)
  Both retrieves the chassis warnings into the word pointed by the ptr argument and sets the chassis display using data in the display argument.
`pdc`(PDC_COPROC, PDC_COPROC_DFLT, ptr)
  Identify the coprocessors attached to the CPU. The ptr points to a memory location where data is to be stored. The first word provides a mask for functional coprocessors and the second word is the mask for all present coprocessors.
`pdc`(PDC_DEBUG, PDC_DEBUG_DFLT, ptr)
  Retrieve address of the PDC debugger placed in to the word pointed to by the ptr argument.
`pdc`(PDC_IODC, PDC_IODC_READ, ptr, hpa, entry, addr, count)
  Given a module hpa, retrieve the specified entry from the module's IODC into a memory area at adr of count bytes long at most. The entry index is a one-byte index, with a value of zero being a special case. For the 0th entry, an IODC header of 16 bytes is returned instead of an actual code.
`pdc`(PDC_IODC, PDC_IODC_NINIT, ptr, hpa, spa)
  Non-destructively initialize the memory module specified by the hpa and spa arguments and return the module status after the init in the first word pointed to by the ptr argument, followed by the SPA space size and an amount of available memory bytes in the subsequent two words.
`pdc`(PDC_IODC, PDC_IODC_DINIT, ptr, hpa, spa)
  Same as `PDC_IODC_NINIT` except a destructive memory test is performed.
`pdc`(PDC_IODC, PDC_IODC_MEMERR, ptr, hpa, spa)
  For the memory module that is specified by hpa and spa, return the last most severe error information comprised of copies of IO_STATUS, IO_ERR_RESP, IO_ERR_INFO, and IO_ERR_REQ registers placed into the data area pointed to by the ptr argument, and clear the error status.
`pdc`(PDC_IODC, PDC_IODC_IMEMMASTER, ptr, hpa)
  HPA for the primary memory module is returned in a word pointed to by the ptr argument for a memory module specified by hpa if it's configured as a slave module in an interleave group.
`pdc`(PDC_LAN_STATION_ID, PDC_LAN_STATION_ID_READ, macptr, hpa)
  Retrieve the MAC address for the device at hpa into the data area pointed to by the macptr argument.
`pdc`(PDC_MEMMAP, PDC_MEMMAP_HPA., ptr, path)
  Returns device HPA in the word pointed to by the ptr argument given the device path pointer.
`pdc`(PDC_MODEL, PDC_MODEL_INFO, ptr)
  Returns the System model numbers.
`pdc`(PDC_MODEL, PDC_MODEL_BOOTID, boot_id)
  Set BOOT_ID of the processor module (used during boot process of monarch selection) to a word given in the boot_id argument.
`pdc`(PDC_MODEL, PDC_MODEL_COMP, ptr, index)
  Retrieve processor component versions by issuing this procedure with subsequent indexes in the index argument starting at zero. The component version number is stored in the word pointed to by the ptr argument.
`pdc`(PDC_MODEL, PDC_MODEL_MODEL, ptr, os_id, mod_addr)
  Return a string of 80 chars maximum stored at address mod_addr and conforming to the OS specified by the os_id 16-bit integer (see `PDC_STABLE` for more information on OS ID). A word at the ptr address receives the result string length.
`pdc`(PDC_MODEL, PDC_MODEL_CPUID, ptr)
  Retrieve CPU model information. A word stored at the address given by the ptr argument specifies the CPU revision in the lower 5 bits followed by 7 bits of CPU model number.
`pdc`(PDC_MODEL, PDC_MODEL_CPBALITIES, ptr)
  Retrieve platform capabilities into the word pointed by the ptr argument. Bit 0 and 1 specify that a 64- or 32-bit OS is supported, respectively.
`pdc`(PDC_MODEL, PDC_MODEL_GETBOOTOPTS, ptr)
  Retrieve the currently enabled, overall supported, and enabled by default boot test masks respectively stored at location pointed to by the ptr argument.
`pdc`(PDC_MODEL, PDC_MODEL_SETBOOTOPTS, ptr, disable, enable)
  Disable boot tests specified by mask in the disable argument and enable boot tests specified by the mask given in the enable argument. The memory location pointed to by ptr will contain the resulting masks as returned by the PDC_MODEL_GETBOOTOPTS function. If an attempt is made to enable and disable the same test in one call, a PDC_ERR_INVAL will be returned.
`pdc`(PDC_NVM, PDC_NVM_READ, offset, ptr, count)
  Read contents of the NVM at offset into the memory area pointed to by the ptr argument of no more than count bytes.

  The format of the NVM is as follows:

  offset | size | contents
  0x00 | 0x24 | HV dependent
  0x24 | 0x20 | bootpath
  0x44 | 0x04 | ISL revision
  0x48 | 0x04 | timestamp
  0x4c | 0x30 | LIF utility entries
  0x7c | 0x04 | entry point
  0x80 | 0x80 | OS panic information

`pdc`(PDC_NVM, PDC_NVM_WRITE, offset, ptr, count)
  Write data pointed to by the ptr argument of count bytes at address in the NVM.
`pdc`(PDC_NVM, PDC_NVM_SIZE, ptr)
  Put the size of Non-Volatile Memory into the word pointed to by the ptr argument.
`pdc`(PDC_NVM, PDC_NVM_VRFY)
  Verify that the contents of NVM are valid.
`pdc`(PDC_NVM, PDC_NVM_INIT)
  Reset the contents of NVM to zeroes without any arguments.
`pdc`(PDC_HPA, PDC_HPA_DFLT, ptr)
  The data returned provides the monarch CPUs HPA in the word pointed to by ptr.
`pdc`(PDC_HPA, PDC_HPA_MODULES, ptr)
  Retrieve the bit mask for devices on the CPU bus into the data location pointed to by ptr. The first word is a bitmask for devices 0-31, and the second is a bitmask for devices 32-63, where bits set to one specify that the corresponding device number is on the same bus as the CPU.
`pdc`(PDC_PIM, PDC_PIM_HPMC, offset, ptr, count)
  Get HPMC data from offset in Processor Internal Memory (PIM) into a ptr memory area of no more than count bytes in size. Data provided includes (in the order it is copied into the buffer): general registers (r0-r31), control registers (cr0-cr31), space registers (sr0-sr7), IIA space tail, IIA offset tail, check type, CPU state, cache check, TLB check, bus check, assist check, assist state, path info, system responder address, system requestor address, FPU registers (fpr0-fpr31).
`pdc`(PDC_PIM, PDC_PIM_SIZE, ptr)
  Return the amount of data available in bytes in the word pointed to by ptr.
`pdc`(PDC_PIM, PDC_PIM_LPMC, offset, ptr, count)
  Get LPMC data from offset in PIM into a ptr memory area of no more than count bytes in size. Data provided includes: HV dependent 0x4a words, check type, HV dependent word, cache check, TLB check, bus check, assist check, assist state, path info, system responder address, system requestor address, FPU registers (fpr0-fpr31).
`pdc`(PDC_PIM, PDC_PIM_SBD, offset, ptr, count)
  Get Soft Boot Data from offset in PIM into a ptr memory area of no more than count bytes in size. Data provided includes: general registers (r0-r31), control registers (cr0-cr31), space registers (sr0-sr7), IIA space tail, IIA offset tail, HV dependent word, CPU state.
`pdc`(PDC_PIM, PDC_PIM_TOC, offset, ptr, count)
  Get TOC (Transfer Of Control) data from offset in PIM into a ptr memory area of no more than count bytes in size. Data provided includes: general registers (r0-r31), control registers (cr0-cr31), space registers (sr0-sr7), IIA space tail, IIA offset tail, HV dependent word, CPU state.
`pdc`(PDC_POW_FAIL, PDC_POW_FAIL_DFLT)
  Prepare for power fail. On the machines that provide power failure interrupts, this function is to be called after the operating system has completed shutdown(8) to finish system-dependent tasks and power down. This function only requires 512 bytes of stack.
`pdc`(PDC_PROC, PDC_PROC_STOP)
  Stop the currently executing processor and also disable bus requestorship, disable interrupts, and exclude the processor from cache coherency protocols. The caller must flush any necessary data from the cache before calling this function.
`pdc`(PDC_PROC, PDC_PROC_RENDEZVOUS)
  Enter the reset rendezvous code on the current processor. This function is only implemented on category B processors and implementation is optional on category A processors.
`pdc`(PDC_PSW, PDC_PSW_GETMASK, ptr)
  Get the mask of default bits implemented into a word pointed to by the ptr argument. The following mask values are possible:

  1
    Default endianness bit is available.
  2
    Default word width bit is available.
`pdc`(PDC_PSW, PDC_PSW_DEFAULTS, ptr)
  Retrieve the default PSW bits into the word pointed to by the ptr argument.
`pdc`(PDC_PSW, PDC_PSW_SETDEFAULTS, bits)
  Set the default PSW bits.
`pdc`(PDC_SOFT_POWER, PDC_SOFT_POWER_INFO, ptr)
  Retrieve “power” register address into the word pointed to by the ptr argument. Bit-0 in the “power” register address being set specifies the power button being depressed. No dampening is required, unlike with the lasi(4) power circuit.
`pdc`(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, ptr, stat)
  Enable (zero stat) or disable (non-zero stat) the soft power function, where disable means the machine will turn immediately off should the power get depressed. The ptr argument still points to the data provided previously by the PDC_SOFT_POWER_INFO call.
`pdc`(PDC_STABLE, PDC_STABLE_READ, offset, ptr, count)
  Read contents of the “Stable Storage” at offset into the memory area pointed to by the ptr argument of no more than count bytes.

  The format of the stable storage is as follows:

  offset | size | contents
  0x0000 | 0x20 | primary bootpath
  0x0020 | 0x20 | reserved
  0x0040 | 0x02 | OS ID
  0x0042 | 0x16 | OS dependent
  0x0058 | 0x02 | diagnostic
  0x005a | 0x03 | reserved
  0x005d | 0x02 | OS dependent
  0x005f | 0x01 | fast size
  0x0060 | 0x20 | console path
  0x0080 | 0x20 | alternative boot path
  0x00a0 | 0x20 | keyboard path
  0x00c0 | 0x20 | reserved
  0x00e0 | size | OS dependent

  The “OS ID” field may have the following values:

  value | OS
  0x000 | No OS-dependent info
  0x001 | HP-UX
  0x002 | MPE-iX
  0x003 | OSF
  0x004 | HP-RT
  0x005 | Novell Netware

  The “fast size” field is the amount of memory to be tested upon system boot and is a power of two multiplier for 256KB. Values of 0xe and 0xf are reserved.

`pdc`(PDC_STABLE, PDC_STABLE_WRITE, address, ptr, count)
  Write data pointed to by the ptr argument of count bytes at address in the “Stable Storage”.
`pdc`(PDC_STABLE, PDC_STABLE_SIZE, ptr)
  Put the size of the “Stable Storage” into the word pointed to by the ptr argument.
`pdc`(PDC_STABLE, PDC_STABLE_VRFY, ptr)
  Verify that the contents of the “Stable Storage” are valid.
`pdc`(PDC_STABLE, PDC_STABLE_INIT, ptr)
  Reset the contents of the “Stable Storage” to zeroes.
`pdc`(PDC_SYSMAP, PDC_SYSMAP_FIND, ptr, path, number)
  Map module number into HPA and also provide an area size starting at HPA and a number of additional addresses placed into the data area pointed to by the ptr argument words one, two, and three, respectively. The device path is placed into the data area pointed to by the path argument.
`pdc`(PDC_SYSMAP, PDC_SYSMAP_ADDR, ptr, im, ia)
  Retrieve a list of additional addresses for the module number im for the address index ia. The result is placed into the data area pointed to by ptr, where the first word gives the address and the second the size of the area.
`pdc`(PDC_SYSMAP, PDC_SYSMAP_HPA, ptr, path_ptr)
  Map device path_ptr into device's HPA placed into a word pointed to by the ptr argument.
`pdc`(PDC_TLB, PDC_TLB_INFO, ptr)
  Retrieve the hardware TLB handler parameters. This includes a minimal and maximal size for the page table, in bytes, stored into words zero and one, respectively, in the data area pointed to by the ptr argument.
`pdc`(PDC_TLB, PDC_TLB_CONFIG, ptr, base, size, param)
  Configure the hardware TLB miss handler given the same parameters fetched previously with PDC_TLB_INFO into data area pointed to by the ptr and page table base address, page table size, and handler parameters param. The hardware TLB handler parameter bits are as follows:

  1
    Enable the hardware TLB miss handler. The default is to load cr28 with the faulted page table entry address.
  4
    Pointer to the next page table entry is put into cr28.
  6
    Next pointer field of the page table entry is put into cr28.

  Resetting the page table address and/or size without disabling the hardware TLB miss handler is allowed. Any changes made are immediate upon Code or Data virtual address translation bits are set in PSW.

`pdc`(PDC_TOD, PDC_TOD_READ, ptr)
  Read the TOD, which is a UNIX Epoch time, into the data area pointed to by the ptr argument. That includes seconds in the first word and microseconds in the second.
`pdc`(PDC_TOD, PDC_TOD_WRITE, sec, usec)
  Write TOD with UNIX Epoch time with sec seconds and usec microseconds.
`pdc`(PDC_TOD, PDC_TOD_ITIMER, ptr)
  Get TOD and CPU timer accuracy into the data location pointed to by the ptr argument. The first two words specify a double floating-point value giving CPU timer frequency. The next two words provide accuracy in parts per billion for the TOD and CPU timer, respectively.

# FILES

machine/pdc.h
  C header file with relevant definitions.
/sys/arch/hppa/dev/cpudevs
  System components' version numbers.
/dev/console
  System console device.

# DIAGNOSTICS

Upon successful completion all procedures return zero. The following error codes are returned in case of failures:

PDC_ERR_NOPROC
  No such procedure
PDC_ERR_NOPT
  No such option
PDC_ERR_COMPL
  Unable to complete without error
PDC_ERR_EOD
  No such device
PDC_ERR_INVAL
  Invalid argument
PDC_ERR_PFAIL
  Aborted by powerfail

# SEE ALSO

intro(4), io(4), lasi(4)

Hewlett-Packard, PA-RISC 1.1 Firmware Architecture Reference Specification, March 8, 1999.

Hewlett-Packard, PA-RISC 2.0 Firmware Architecture Reference Specification, March 7, 1999.

March 31, 2022 | Debian