diff options
Diffstat (limited to 'c/src/lib/libbsp/powerpc/mbx8xx/README')
| -rw-r--r-- | c/src/lib/libbsp/powerpc/mbx8xx/README | 148 |
1 files changed, 107 insertions, 41 deletions
diff --git a/c/src/lib/libbsp/powerpc/mbx8xx/README b/c/src/lib/libbsp/powerpc/mbx8xx/README index 7a1c9fe5b2..58e1690075 100644 --- a/c/src/lib/libbsp/powerpc/mbx8xx/README +++ b/c/src/lib/libbsp/powerpc/mbx8xx/README @@ -126,8 +126,8 @@ Board description ----------------- Clock rate: 50MHz Entry level boards, 40 MHz others. Bus width: 8/32 bit Flash, 32 bit DRAM -FLASH: 2-4MB, 120ns -RAM: 4-16MB EDO, 60ns DRAM DIMM +FLASH: 2-4MB, 120ns +RAM: 4-16MB EDO, 60ns DRAM DIMM Installation @@ -146,10 +146,10 @@ will build for a MBX860-002. Look at rtems/make/custom/mbx8xx.cfg for the specific list of boards supported and their corresponding names. An example build command is: - make RTEMS_BSP=mbx821_001 all debug + make RTEMS_BSP=mbx821_001 VARIANT=DEBUG -This will build the optimized and debug versions of all RTEMS libraries, -samples and tests (if the latter are enabled). +This will build the debug version of all RTEMS libraries, samples and tests +(if the latter are enabled). The Software Engineering Group of the Institute for Information Technology only owns an MBX821-001 and MBX86-002. The only provided config files are @@ -157,7 +157,7 @@ mbx821_001.cfg and mbx860_002.cfg. A SPECIFIC CONFIG FILE IS REQUIRED. Use one of the provided files as a template to create a specific config file for another model. -We rely on EPPC-BUG to download to the targets. We use the 'PLH" command. +We rely on EPPC-BUG to download to the targets. We use the "PLH" command. We enabled a TFTP deamon on our development host. @@ -165,38 +165,108 @@ Port Description Console driver --------------- -This BSP includes an termios-capable console driver that supports SMC1, -SMC2, SCC2, and SCC3 and SCC4 if present. The RTEMS console is selected -in rtems/make/custom/mbx8xx.cfg with the CONSOLE_MINOR variable. We -normally run with the RTEMS application console on SMC1. +This BSP includes an termios-capable asynchronous serial line driver +that supports SMC1, SMC2, SCC2, and SCC3 and SCC4 if present. The RTEMS +console is selected in rtems/make/custom/mbx8xx.cfg with the +CONSOLE_MINOR variable. We normally run with the RTEMS application +console on SMC2. SMC1 is used by the debugger. + +Support is provided for five different modes of operation: + + 1. polled I/O done by EPPC-Bug with termios support, + 2. polled I/O done by EPPC-Bug without termios support, + 3. polled I/O done by the supplied device driver with termios support, + 4. polled I/O done by the supplied device driver without termios support, + 5. interrupt-driven I/O done by the supplied device driver with termios + support. + +The mode of operation of the serial driver is determined at build time +by the value of the UARTS_IO_MODE constant in rtems/make/custom/mbx8xx.cfg. +Edit the file to select the type of I/O desired before building RTEMS. +The choices are: + + 0 - polled I/O done by the supplied device driver, + 1 - interrupt-driven I/O done by the supplied device driver, + 2 - polled I/O done by EPPC-Bug. + +Also set the value of UARTS_USE_TERMIOS to select whether termios should +be used to perform buffering and input/output processing. Without termios +support, input processing is limited to the substitution of LF for a +received CR, and output processing is limited to the transmission of a +CR following the transmission of a LF. The choices for UARTS_USE_TERMIOS are: + + 0 - do not use termios + 1 - use termios -Support is provided for polled and interrupt-driven terminal I/O. Interrupt- -driven I/O is selected by setting the UARTS_USE_INTERRUPTS variable in -rtems/make/custom/mbx8xx.cfg. If the variable is not set, or if it is set -to zero, polled I/O is used. If the EPPCBUG_SMC1 variable is set in -rtems/make/custom/mbx8xx.cfg, SMC1 will be used in polled mode with all -I/O done by EPPC-Bug rather than the supplied device driver. This mode -should be used if the application console is shared with EPPC-Bug. +In most real-time applications, the driver should be configured to use +termios and interrupt-driven I/O. Special requirements may dictate otherwise. Polled I/O must be used when running the timing tests. It must also be used -to run some other tests and some samples, such as the cdtest. Applications -would normally use interrupt-driven I/O. +to run some other tests and some samples, such as the cdtest. Some tests +change the interrupt mask and will hang interrupt-driven I/O indefinitely. +Others, such as cdtest, perform console output from the static constructors +before the console is opened, causing the test to hang. Still other tests +produce output that is supposed to be in some specific order. For these +tests, termios should not be used, as termios buffers output and the +transmission of the buffers occur at somewhat unpredictable times. + +The real solution is to fix the tests so that they work with interrupt-driven +I/O and termios. + + +printk() and debug output +----------------------- + +The implementation of printk() in RTEMS is mostly independent of most system +services. The printk() function can therefore be used to print messages to a +debug console, particularly when debugging startup code or device drivers, +i.e. code that runs before the console driver is opened or that runs with +interrupts disabled. + +Support is provided to send printk output to any port. Specify the desired +port at build time in rtems/make/custom/mbx8xx.cfg by setting the value +of PRINTK_MINOR to one of SMC1_MINOR, SMC2_MINOR, SCC2_MINOR, SCC3_MINOR, +or SCC4_MINOR. + +Select the type of output desired for printk() by setting the value of +PRINTK_IO_MODE in rtems/make/custom/mbx8xx.cfg. The choices are: + + 0 - polled I/O done by the supplied device driver, + 1 - interrupt-driven I/O done by the supplied device driver, + 2 - polled I/O done by EPPC-Bug. + +printk() does not use termios. + +If the printk() port is opened by RTEMS, then PRINK_IO_MODE mode must have +the same value as UARTS_IO_MODE, otherwise the I/O functions will be in +conflict. Interrupt-driven printk() output is only possible if the port is +opened before hand by an RTEMS application, and is of dubious value... EPPC-Bug and I/O ---------------- +IMPORTANT: When using EPPC-Bug 1.1 for polled I/O, only the SMC1 port is +usable. This is a deficiency of the firmware which may be fixed in later +revision. When using this monitor with UARTS_IO_MODE set to 2, CONSOLE_MINOR +must be set to SMC1_MINOR. Similarly, if PRINTK_IO_MODE set to 2, +PRINTK_MINOR must be set to SMC1_MINOR. When UARTS_IO_MODE is set to 2, +only SMC1 is usable. + Be warned that when EPPC-Bug does I/O through a serial port, all interrupts get turned off in the SIMASK register! This is a definite bug in release 1.1 -of the firmware. It may have been fixed in later releases. +of the firmware. It may have been fixed in later releases. EPPB-Bug does +I/O through its debug port whenever it is given control, e.g. after a +breakpoint is hit, not just when it is used to perform polled I/O on behalf +of RTEMS applications. In particular, in our configuration, we have gdb +communication with EPPC-Bug through SMC1. -To solve this problem that occurs when GDB communicates with EPPC-Bug, -whenever the BSP manipulates the SIMASK, it makes copy of the written -in a global variable called 'simask_copy'. That value must be restored by -GDB before execution resumes. The following commands placed in the .gdbinit -file takes care of this: +To solve this problem, whenever the BSP manipulates the SIMASK, it makes a +copy of the written value in a global variable called 'simask_copy'. That +value must be restored by GDB before execution resumes. The following commands +placed in the .gdbinit file takes care of this: -# GDB Initialization file for EPPCBug. +# GDB Initialization file for EPPC-Bug. define hook-stepi set language c @@ -234,6 +304,12 @@ set *(int *)0xFA200014=simask_copy set language auto end +IMPORTANT: When using EPPC-Bug on SMC1, either for debugging or for polled I/O, +EPPCBUG_SMC1 must be defined in rtems/make/custom/mbx8xx.cfg. Defining this +constant prevents the device driver from re-initializing SMC1. It also causes +the network driver, the clock driver, and the asynchronous serial line driver +to maintain simask_copy for use by gdb. + Floating-point -------------- @@ -252,12 +328,11 @@ All development was based on the eth_comm port. Host System ----------- -12345678901234567890123456789012345678901234567890123456789012345678901234567890 The port was developed on Pentiums II and III running RedHat Linux 6.0 and 6.1. The following tools were used: - - GNU gcc snapshot dated 19991208 configured for powerpc-rtems; - - GNU binutils 2.9.1 configured for powerpc-rtems; + - GNU gcc snapshot dated 20000214 configured for powerpc-rtems; + - GNU binutils 2.10 configured for powerpc-rtems; Gcc 2.95.2 also worked. Gcc 2.95.1 will not compile the console driver with -O4 or -O3. Compile it manually with -O2. @@ -299,11 +374,6 @@ 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? @@ -346,10 +416,6 @@ 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. @@ -357,16 +423,16 @@ Single processor tests: All tests passed, except the following ones: checker had had a chance to detect the corrupted stack. -Multi-processort tests: not applicable -- No MPCI layer yet. +Multi-processort tests: not applicable. Timing tests: - See the times-mbx821 and times-860 files for the results of the + See the times-mbx821 and times-mbx860 files for the results of the timing tests. Network tests: - Network driver is being implemented. + Worked. |