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diff --git a/Documentation/fmc/identifiers.txt b/Documentation/fmc/identifiers.txt new file mode 100644 index 000000000000..3bb577ff0d52 --- /dev/null +++ b/Documentation/fmc/identifiers.txt @@ -0,0 +1,168 @@ +FMC Identification +****************** + +The FMC standard requires every compliant mezzanine to carry +identification information in an I2C EEPROM. The information must be +laid out according to the "IPMI Platform Management FRU Information", +where IPMI is a lie I'd better not expand, and FRU means "Field +Replaceable Unit". + +The FRU information is an intricate unreadable binary blob that must +live at offset 0 of the EEPROM, and typically extends for a few hundred +bytes. The standard allows the application to use all the remaining +storage area of the EEPROM as it wants. + +This chapter explains how to create your own EEPROM image and how to +write it in your mezzanine, as well as how devices and drivers are +paired at run time. EEPROM programming uses tools that are part of this +package and SDB (part of the fpga-config-space package). + +The first sections are only interesting for manufacturers who need to +write the EEPROM. If you are just a software developer writing an FMC +device or driver, you may jump straight to *note SDB Support::. + + +Building the FRU Structure +========================== + +If you want to know the internals of the FRU structure and despair, you +can retrieve the document from +`http://download.intel.com/design/servers/ipmi/FRU1011.pdf' . The +standard is awful and difficult without reason, so we only support the +minimum mandatory subset - we create a simple structure and parse it +back at run time, but we are not able to either generate or parse more +arcane features like non-english languages and 6-bit text. If you need +more items of the FRU standard for your boards, please submit patches. + +This package includes the Python script that Matthieu Cattin wrote to +generate the FRU binary blob, based on an helper libipmi by Manohar +Vanga and Matthieu himself. I changed the test script to receive +parameters from the command line or from the environment (the command +line takes precedence) + +To make a long story short, in order to build a standard-compliant +binary file to be burned in your EEPROM, you need the following items: + + Environment Opt Official Name Default +--------------------------------------------------------------------- + FRU_VENDOR -v "Board Manufacturer" fmc-example + FRU_NAME -n "Board Product Name" mezzanine + FRU_SERIAL -s `Board Serial Number" 0001 + FRU_PART -p "Board Part Number" sample-part + FRU_OUTPUT -o not applicable /dev/stdout + +The "Official Name" above is what you find in the FRU official +documentation, chapter 11, page 7 ("Board Info Area Format"). The +output option is used to save the generated binary to a specific file +name instead of stdout. + +You can pass the items to the FRU generator either in the environment +or on the command line. This package has currently no support for +specifying power consumption or such stuff, but I plan to add it as +soon as I find some time for that. + +FIXME: consumption etc for FRU are here or in PTS? + +The following example creates a binary image for a specific board: + + ./tools/fru-generator -v CERN -n FmcAdc100m14b4cha \ + -s HCCFFIA___-CR000003 -p EDA-02063-V5-0 > eeprom.bin + +The following example shows a script that builds several binary EEPROM +images for a series of boards, changing the serial number for each of +them. The script uses a mix of environment variables and command line +options, and uses the same string patterns shown above. + + #!/bin/sh + + export FRU_VENDOR="CERN" + export FRU_NAME="FmcAdc100m14b4cha" + export FRU_PART="EDA-02063-V5-0" + + serial="HCCFFIA___-CR" + + for number in $(seq 1 50); do + # build number-string "ns" + ns="$(printf %06d $number)" + ./fru-generator -s "${serial}${ns}" > eeprom-${ns}.bin + done + + +Using SDB-FS in the EEPROM +========================== + +If you want to use SDB as a filesystem in the EEPROM device within the +mezzanine, you should create one such filesystem using gensdbfs, from +the fpga-config-space package on OHWR. + +By using an SBD filesystem you can cluster several files in a single +EEPROM, so both the host system and a soft-core running in the FPGA (if +any) can access extra production-time information. + +We chose to use SDB as a storage filesystem because the format is very +simple, and both the host system and the soft-core will likely already +include support code for such format. The SDB library offered by the +fpga-config-space is less than 1kB under LM32, so it proves quite up to +the task. + +The SDB entry point (which acts as a directory listing) cannot live at +offset zero in the flash device, because the FRU information must live +there. To avoid wasting precious storage space while still allowing +for more-than-minimal FRU structures, the fmc.ko will look for the SDB +record at address 256, 512 and 1024. + +In order to generate the complete EEPROM image you'll need a +configuration file for gensdbfs: you tell the program where to place +the sdb entry point, and you must force the FRU data file to be placed +at the beginning of the storage device. If needed, you can also place +other files at a special offset (we sometimes do it for backward +compatibility with drivers we wrote before implementing SDB for flash +memory). + +The directory tools/sdbfs of this package includes a well-commented +example that you may want to use as a starting point (the comments are +in the file called -SDB-CONFIG-). Reading documentation for gensdbfs +is a suggested first step anyways. + +This package (generic FMC bus support) only accesses two files in the +EEPROM: the FRU information, at offset zero, with a suggested filename +of IPMI-FRU and the short name for the mezzanine, in a file called +name. The IPMI-FRU name is not mandatory, but a strongly suggested +choice; the name filename is mandatory, because this is the preferred +short name used by the FMC core. For example, a name of "fdelay" may +supplement a Product Name like "FmcDelay1ns4cha" - exactly as +demonstrated in `tools/sdbfs'. + +Note: SDB access to flash memory is not yet supported, so the short +name currently in use is just the "Product Name" FRU string. + +The example in tools/sdbfs includes an extra file, that is needed by +the fine-delay driver, and must live at a known address of 0x1800. By +running gensdbfs on that directory you can output your binary EEPROM +image (here below spusa$ is the shell prompt): + + spusa$ ../fru-generator -v CERN -n FmcDelay1ns4cha -s proto-0 \ + -p EDA-02267-V3 > IPMI-FRU + spusa$ ls -l + total 16 + -rw-rw-r-- 1 rubini staff 975 Nov 19 18:08 --SDB-CONFIG-- + -rw-rw-r-- 1 rubini staff 216 Nov 19 18:13 IPMI-FRU + -rw-rw-r-- 1 rubini staff 11 Nov 19 18:04 fd-calib + -rw-rw-r-- 1 rubini staff 7 Nov 19 18:04 name + spusa$ sudo gensdbfs . /lib/firmware/fdelay-eeprom.bin + spusa$ sdb-read -l -e 0x100 /lib/firmware/fdelay-eeprom.bin + /home/rubini/wip/sdbfs/userspace/sdb-read: listing format is to be defined + 46696c6544617461:2e202020 00000100-000018ff . + 46696c6544617461:6e616d65 00000200-00000206 name + 46696c6544617461:66642d63 00001800-000018ff fd-calib + 46696c6544617461:49504d49 00000000-000000d7 IPMI-FRU + spusa$ ../fru-dump /lib/firmware/fdelay-eeprom.bin + /lib/firmware/fdelay-eeprom.bin: manufacturer: CERN + /lib/firmware/fdelay-eeprom.bin: product-name: FmcDelay1ns4cha + /lib/firmware/fdelay-eeprom.bin: serial-number: proto-0 + /lib/firmware/fdelay-eeprom.bin: part-number: EDA-02267-V3 + +As expected, the output file is both a proper sdbfs object and an IPMI +FRU information blob. The fd-calib file lives at offset 0x1800 and is +over-allocated to 256 bytes, according to the configuration file for +gensdbfs. |