Subversion Repositories openrisc

#

#  $Id: README,v 1.2 2001-09-27 12:00:19 chris Exp $

#

This is a README file for the MVME167 port of RTEMS 4.5.0.

Please send any comments, improvements, or bug reports to:

Charles-Antoine Gauthier

charles.gauthier@nrc.ca

or

Darlene Stewart

Darlene.Stewart@nrc.ca

Software Engineering Group

Institute for Information Technology

National Research Council of Canada

Ottawa, ON, K1A 0R6

Canada

WARNING:

--------

The network driver is currently being worked on. It is somewhat functional,

but it does run out of buffers under certain conditions. The code is

also undergoing a substantial reorganization. Before making any changes,

you should check with us for the availability of updates.

Note from Joel:  The ttcp performance reported is very nice even if the

driver is still early in its life. :)

Disclaimer

----------

The National Research Council of Canada is distributing this RTEMS

board support package for the Motorola MVME167 as free software; you

can redistribute it and/or modify it under terms of the GNU General

Public License as published by the Free Software Foundation; either

version 2, or (at your option) any later version.  This software is

distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License

for more details. You should have received a copy of the GNU General

Public License along with RTEMS; see file COPYING. If not, write to

the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

Under no circumstances will the National Research Council of Canada

nor Her Majesty the Queen in right of Canada assume any liablility

for the use this software, nor any responsibility for its quality or

its support.

Installation

------------

Nothing unique to the MVME167. It uses the standard build process for

m68k targets. You will need to edit linkcmds to put in the start address

of your board. We do TFTP transfers to our target. The mvme167.cfg file

builds only the ELF images, which we download to the target, skipping

over the first 0x54 bytes; Motorola S-records are not generated. Edit

this file if you want S-records.

Port Description

Console driver

---------------

This BSP includes an termios-capable console driver that supports all

four serial ports on the MVME167 model. The RTEMS console, /dev/console,

corresponds to channel 1 in the CD2401. This corresponds to Serial Port

2/TTY01 on the MVME712M. Serial Port 1/Console is normally used by 167Bug;

do not open /dev/tty00 if you are debugging using 167Bug.

The console is initialized with whatever parameters are set up in termios

before it calls the firtOpen driver callback, EXCEPT THAT HARDWARE

HANDSHAKING IS TURNED OFF, i.e. CLOCAL is set in the struct termios

c_cflag field. We use 3-wire cables for I/O, and find hardware handshaking

a pain. If you enable hardware handshaking, you must drive CTS* low on the

CD2401 for output to occur. If the port is in the DTE configuration, you

must drive the RS-232 CTS line to space; if the port is in the DCE

configuration, you must drive the RS-232 RTS line to space.

Limited support is provided for polled terminal I/O. This is used when

running the timing tests. Set the CD2401_POLLED_IO manifest constant to 1

in rtems/c/src/lib/libbsp/m68k/mvme167/console/console.c to enable polled

I/O. In this case, I/O is done through 167Bug, usually to the Serial Port

1/Console port. Interrupt-driven and polled I/O cannot be mixed in the

MVME167.

Floating-point

The MC68040 has a built-in FPU. This FPU does not implement all the

instruction of the MC68881/MC68882 floating-point coprocessors in

hardware. The -m68040 compilation options instructs gcc to not generate

the missing instructions. All of the RTEMS code is built this way. Some

of the missing functionality must be supplied by external libraries. The

required functions are part of libgcc.a.

The issue gets complicated because libc, libm and libgcc do not come as

m68040-specific variants. The default variants of these libraries are for the

MC68020 and MC68030. There are specific variants for the MC68000 (which has

limited addressing modes with respect to later family members), and specific

variants for systems without a floating-point unit, either a built-in FPU or

a coprocessor. These latter variants will be referred to as the msoft-float

variants. There is a msoft-float variant for the MC68000, and one for the

other family members.

The default variants of libc, libm and libgcc appear to work just fine for the

MC68040, AS LONG AS NO FLOATING POINT FUNCTIONS ARE CALLED. In particular,

printf() and scanf() raise unimplemented floating-point instruction exceptions

at run time. Expect almost every function that must compute a floating-point

result to also raise unimplemented floating-point instruction exceptions. Do

not use these variants if your application does any floating-point operations,

unless you use the Motorola FPSP package (described further down).

The msoft-float variants do print out floating-point numbers properly, but we

have not tested them extensively, so use them with caution. In particular,

the Paranoia test fails when linked with the msoft-float variants of the

libraries; it goes into an infinite loop after milestone 40.

MSOFT_FLOAT VARIANTS MUST BE USED TOGETHER. If you use the msoft-float variant

of libc and libm, you must also linked with the msoft-float variant of libgcc,

otherwise calls such as printf() print out floating-point values incorrectly.

RTEMS comes with the Motorola FPSP (Floating-Point Support Package) for the

MC68040 (rtems/c/src/lib/libcp/m68k/m68040/fpsp). This package emulates the

missing floating-point instructions. It is built automatically for the

MVME167 and installed in bsp_start().

The FPSP allows the use of the default variants of libc, libm and libgcc.

It also runs the paranoia test properly, and prints out the correct results.

It should probably be used in preference to the msoft-float libraries, as it

appears to work better. The disadvantage of the FPSP is that it increases the

size of the executable by about 60KB and that it relies on run time

exceptions.

If your application does not do any floating-point operations at all, you

should consider disabling the FPSP. In bsp_start(), emove the call to

M68KFPSPInstallExceptionHandlers(), and uncomment the three lines in

mvme167.cfg that redefine which variants of libc, libm and libgcc to link

against.

Cache Control and Memory Mapping

If Jumper J1-7 is installed, the data cache will be turned on. If Jumper

J1-6 is installed, the instruction cache will be turned on. Removing the

jumper causes the corresponding cache to be left disabled.

If Jumper J1-5 is installed, the data cache will be placed in copyback

mode. If it is removed, it will be placed in writethrough mode.

Currently, block address translation is set up to map the virtual

0x00000000--0x7FFFFFFF to the physical range 0x00000000--0x7FFFFFFF. The

port relies on the hardware to raise exceptions when addressing

non-existent memory. Caching is not controllable on a finer grain.

Miscellaneous

The timer and clock drivers were patterned after the MVME162 and MVME152

ports.

At this time, we do not have an MPCI layer for the MVME167. We are planning

to write one.

This port supplies its own fatal_error_handler, which attempts to print some

error message through 167Bug (on the Serial Port 1/Console on the MVME712M).

Host System

-----------

The port was initially developed on an RS-6000 running AIX 4.2. The following

tools were used:

    - GNU gcc 2.8.1 configured for a powerpc-ibm-aix4.2.0.0 host and

      m68k-rtems target;

    - GNU binutils 2.9.1 configured for a powerpc-ibm-aix4.2.0.0 host and

      m68k-rtems target;

It was also tested on a Pentium II-based PC running Windows NT Workstation 4.0

and the Cygnus Cygwin32 release b20.1 environment, with the following tools:

    - EGCS 1.1.1 configured for a i586-cygwin32 host and m68k-rtems target;

    - GNU binutils 2.9.4 configured for a i586-cygwin32 host and m68k-rtems

      target;

With the latter environment, be patient; builds take a very looong time...

Current development is done on a Pentium III PC running RedHat Linux 6.1.

At the time this README was composed, the latest working compiler that was

used successfully was gcc version 2.96 20000213 (experimental). Both the C

and C++ compilers were working. Binutils 2.9.1 are used.

Known Problems

--------------

The cdtest will not run with interrupt-driven I/O. The reason is that the

constructors for the static objects are called at boot time when the

interrupts are still disabled. The output buffer fills up, but never empties,

and the application goes into an infinite loop waiting for buffer space. This

should have been documented in the rtems/c/src/tests/PROBLEMS file. The moral

of this story is: do not do I/O from the constructors or destructors of static

objects.

The cpuuse and malloctest tests do not work properly, either with polled I/O

or interrupt-driven I/O. They are known not to work with interrupt-driven I/O,

but should work with polled I/O?

Output stops prematurely in the termios test when the console is operating in

interrupt-driven mode because the serial port is re-initialized before all

characters in the last raw output buffer are sent. Adding calls to tcdrain()

in the test task helps, but it does not solve the problem. What happens is

that the CD2401 raises a transmit interrupt when the last character in the

DMA buffer is written into the transmit FIFO, not when the last character

has been transmitted. When tcdrain() returns, there might be up to 16

characters in the output FIFO. The call to tcsetattr() causes the serial port

to re-initialize, at which point the output FIFO is cleared. We could not find

a way to detect whether characters are still in the FIFO and to wait for them

to be transmitted.

The first raw buffer to be transmitted after the console is re-initialized

with tcsetattr() is garbled. At this time, it does not seem worth while to

track this problem down.

In the stackchk test, an access fault exception is raised after the stack is

blown. This is one case were overwritting the first or last 16 bytes of the

stack does cause problems (but hey, an exception occurred, which is better

than propagating the error).

In the stackchk test, an access fault exception is raised after the stack is

blown. This is one case were overwritting the first or last 16 bytes of the

stack does cause problems (but hey, an exception occurred, which is better

than propagating the error).

When using interrupt-driven I/O, psx08 produces all the expected output, but

it does not return control to 167Bug. Is this test supposed to work with

interrupt-driven console I/O?

What's new

----------

Support for Java is being actively worked on.

Thanks

------

- to On-Line Applications Research Corporation (OAR) for developing

RTEMS and making it available on a Technology Transfer basis;

- to FSF and Cygnus Support for great free software;

Test Configuration

------------------

Board:                Motorola MVME167

CPU:                  Motorola MC68040

Clock Speed:          25 MHz

RAM:                  4 MBytes of 32-bit DRAM with parity

Cache Configuration:  Instruction cache on; data cache on, copyback mode.

Times Reported in:    microseconds

Timer Source:         VMEchip2 Tick Timer 1

GCC Flags:            -m68040 -g -O4 -fomit-frame-pointer

Console:              Operate in polled mode. Set CD2401_POLLED_IO to 1 in

                      rtems/c/src/lib/libbsp/m68k/mvme167/console/console.c.

Test Results

------------

Single processor tests:  All tests passed, except the following ones:

  - paranoia required the FPSP and the default variants of libm (and libc and

    libgcc) for us. It may work with the msoft-float variants for you, but it

    does require the FPSP.

  - cpuuse and malloctest did not work.

  - The stackchk test got an access fault exception before the RTEMS stack

    checker had had a chance to detect the corrupted stack.

Multi-processort tests:  not applicable -- No MPCI layer yet.

Timing tests:

        Context Switch

    context switch: no floating point contexts 12

    context switch: self 3

    context switch: to another task 3

    fp context switch: restore 1st FP task 14

    fp context switch: save idle, restore initialized 5

    fp context switch: save idle, restore idle 15

    fp context switch: save initialized, restore initialized 5

  Miscellaneous

    _ISR_Disable 1

    _ISR_Flash 0

    _ISR_Enable 0

    _Thread_Disable_dispatch 0

    _Thread_Enable_dispatch 3

    _Thread_Set_state 9

    _Thread_Disptach (NO FP) 16

    _Thread_Resume 6

    _Thread_Unblock 4

    _Thread_Ready 6

    _Thread_Get 3

    _Thread_Get: invalid id 0

    _Semaphore_Get 2

        Task Manager

    rtems_task_create 56

    rtems_task_ident 106

    rtems_task_start 21

    rtems_task_restart: calling task 24

    rtems_task_restart: suspended task -- returns to caller 27

    rtems_task_restart: blocked task -- returns to caller 36

    rtems_task_restart: ready task -- returns to caller 27

    rtems_task_restart: suspended task -- preempts caller 40

    rtems_task_restart: blocked task -- preempts caller 51

    rtems_task_restart: ready task -- preempts caller 52

    rtems_task_delete: calling task 67

    rtems_task_delete: suspended task 52

    rtems_task_delete: blocked task 54

    rtems_task_delete: ready task 54

    rtems_task_suspend: calling task 23

    rtems_task_suspend: returns to caller 12

    rtems_task_resume: task readied -- returns to caller 13

    rtems_task_resume: task readied -- preempts caller 22

    rtems_task_set_priority: obtain current priority 8

    rtems_task_set_priority: returns to caller 16

    rtems_task_set_priority: preempts caller 34

    rtems_task_mode: obtain current mode 4

    rtems_task_mode: no reschedule 5

    rtems_task_mode: reschedule -- returns to caller 12

    rtems_task_mode: reschedule -- preempts caller 26

    rtems_task_get_note 8

    rtems_task_set_note 8

    rtems_task_wake_after: yield -- returns to caller 4

    rtems_task_wake_after: yields -- preempts caller 19

    rtems_task_wake_when 36

        Interrupt Manager

    interrupt entry overhead: returns to nested interrupt 5

    interrupt entry overhead: returns to interrupted task 9

    interrupt entry overhead: returns to preempting task 7

    interrupt exit overhead: returns to nested interrupt 1

    interrupt exit overhead: returns to interrupted task 2

    interrupt exit overhead: returns to preempting task 26

        Clock Manager

    rtems_clock_set 20

    rtems_clock_get <1

    rtems_clock_tick 8

        Timer Manager

    rtems_timer_create 8

        rtems_timer_ident 104

    rtems_timer_delete: inactive 12

    rtems_timer_delete: active 13

    rtems_timer_fire_after: inactive 17

    rtems_timer_fire_after: active 18

    rtems_timer_fire_when: inactive 23

    rtems_timer_fire_when: active 23

    rtems_timer_reset: inactive 16

    rtems_timer_reset: active 17

    rtems_timer_cancel: inactive 9

    rtems_timer_cancel: active 10

        Semaphore Manager

    rtems_semaphore_create 22

    rtems_semaphore_ident 119

    rtems_semaphore_delete 24

    rtems_semaphore_obtain: available 10

    rtems_semaphore_obtain: not available -- NO_WAIT 10

    rtems_semaphore_obtain: not available -- caller blocks 35

    rtems_semaphore_release: no waiting tasks 11

    rtems_semaphore_release: task readied -- returns to caller 17

    rtems_semaphore_release: task readied -- preempts caller 27

        Message Queue Manager

    rtems_message_queue_create 85

    rtems_message_queue_ident 103

    rtems_message_queue_delete 32

    rtems_message_queue_send: no waiting tasks 25

    rtems_message_queue_send: task readied -- returns to caller 27

    rtems_message_queue_send: task readied -- preempts caller 39

    rtems_message_queue_urgent: no waiting tasks 26

    rtems_message_queue_urgent: task readied -- returns to caller 28

    rtems_message_queue_urgent: task readied -- preempts caller 39

    rtems_message_queue_broadcast: no waiting tasks 13

    rtems_message_queue_broadcast: task readied -- returns to caller 37

    rtems_message_queue_broadcast: task readied -- preempts caller 45

    rtems_message_queue_receive: available 21

    rtems_message_queue_receive: not available -- NO_WAIT 11

    rtems_message_queue_receive: not available -- caller blocks 37

    rtems_message_queue_flush: no messages flushed 7

    rtems_message_queue_flush: messages flushed 10

        Event Manager

    rtems_event_send: no task readied 7

    rtems_event_send: task readied -- returns to caller 18

    rtems_event_send: task readied -- preempts caller 29

    rtems_event_receive: obtain current events <1

    rtems_event_receive: available 10

    rtems_event_receive: not available -- NO_WAIT 5

    rtems_event_receive: not available -- caller blocks 28

        Signal Manager

    rtems_signal_catch 5

    rtems_signal_send: returns to caller 15

    rtems_signal_send: signal to self 24

    exit ASR overhead: returns to calling task 20

    exit ASR overhead: returns to preempting task 21

        Partition Manager

    rtems_partition_create 30

    rtems_partition_ident 103

    rtems_partition_delete 14

    rtems_partition_get_buffer: available 14

    rtems_partition_get_buffer: not available 9

    rtems_partition_return_buffer 18

        Region Manager

    rtems_region_create 25

    rtems_region_ident 105

    rtems_region_delete 13

    rtems_region_get_segment: available 13

    rtems_region_get_segment: not available -- NO_WAIT 17

    rtems_region_get_segment: not available -- caller blocks 49

    rtems_region_return_segment: no waiting tasks 16

    rtems_region_return_segment: task readied -- returns to caller 35

    rtems_region_return_segment: task readied -- preempts caller 58

        Dual-Ported Memory Manager

    rtems_port_create 13

          rtems_port_ident 103

    rtems_port_delete 14

    rtems_port_external_to_internal 5

    rtems_port_internal_to_external 5

        IO Manager

    rtems_io_initialize <1

    rtems_io_open <1

    rtems_io_close <1

    rtems_io_read <1

    rtems_io_write <1

    rtems_io_control <1

        Rate Monotonic Manager

    rtems_rate_monotonic_create 15

          rtems_rate_monotonic_ident 103

    rtems_rate_monotonic_cancel 16

    rtems_rate_monotonic_delete: active 18

    rtems_rate_monotonic_delete: inactive 20

    rtems_rate_monotonic_period: initiate period -- returns to caller 23

    rtems_rate_monotonic_period: conclude periods -- caller blocks 25

    rtems_rate_monotonic_period: obtain status 13