This document describes the data requirements that OpenBMC has on the machine readable workbook XML generated by Serverwiz2. The requirements in this document are broken up by the OpenBMC functions that use them.
If a particular OpenBMC implementation doesn't use a certain function, then that MRW data isn't required.
The system inventory can be generated from the MRW XML. The inventory typically contains all FRUs (field replaceable units), along with a few non-FRU entities, like the BMC chip and processor cores.
To specify a target in the MRW should be in the inventory:
Note: The BMC and cores will be automatically added without the need to set FRU_NAME.
The BMC device tree can be generated from the MRW XML. For the full device tree to be generated, all of the corresponding devices and connections must be modeled in the MRW XML. For a system built with parts that already have existing XML representations, there are only a few attributes that need to be set. If a new part is being modeled, initial values for some attributes may need to be determined, depending on the part.
The following sections list the system dependent information that the device tree generator requires. The majority of the information it requires is static data that is either already built into the XML representations of the existing parts or pulled in from an include file.
The name of the system as the firmware would know it.
The system manufacturer.
All of the BMC chip attributes that are needed for the device tree are pre-built into the XML representation and don't need to be updated when the device is placed into a system in Serverwiz.
Note: The AST2500 is currently the only BMC XML model that contains all of the necessary device tree attributes.
The device tree can support either 1 or 2 BMC SPI flash chips. This is accomplished by connecting instances of the BMC_FLASH part to the spi-master-unit on the BMC that has its SPI_FUNCTION attribute set to BMC_CODE. If there are multiple chips, they are both connected to the same unit.
To enable a BMC MAC module, its ethernet master unit in the MRW must be connected to an ethernet slave unit. Additionally, the following attributes may need to be set.
This attribute in the ethernet master unit can be set to 1 if the link uses NCSI. The default is 0.
This attribute in the ethernet master unit can be set to 1 if the MAC has hardware checksum enabled, or 0 if not enabled. The default is 1.
UARTs are enabled by connecting the appropriate UART master units in the BMC part to their corresponding uart slave units. No additional attributes are required.
LEDS will be listed in the device tree when LED parts in the MRW are wired to their GPIO master endpoints. The instance name in the MRW is the name of its node in the device tree.
Set to the logic value required to activate the LED - either 0 or 1. The default is 0.
I2C devices are enabled by connecting the I2C master units in the BMC to the I2C slave units on the devices.
The 8 bit hexadecimal I2C address should be set in the slave unit of the end device.
When creating a new XML device model, this attribute should be used to specify which device driver the kernel will use to access the device. For example, ti,423 or bosch,bmp280. For existing parts, this should already be set.
This attribute is also only required when creating a new XML representation of an I2C device. It specifies which other attributes of the device should be listed as properties in the device tree, as required by the device driver for that device. It can contain up to 4 pairs of names, the first name in the pair is the attribute name in the XML to read, and the second name in the pair is the name of the property to call it in the device tree. For example, ATTR_WRITE_PAGE_SIZE, pagesize indicates that the value of the ATTR_WRITE_PAGE_SIZE attribute should be stored in a property called pagesize in the device tree.