Aspeed family boards (``*-bmc``, ``ast2500-evb``, ``ast2600-evb``)
==================================================================

The QEMU Aspeed machines model BMCs of various OpenPOWER systems and
Aspeed evaluation boards. They are based on different releases of the
Aspeed SoC : the AST2400 integrating an ARM926EJ-S CPU (400MHz), the
AST2500 with an ARM1176JZS CPU (800MHz) and more recently the AST2600
with dual cores ARM Cortex A7 CPUs (1.2GHz).

The SoC comes with RAM, Gigabit ethernet, USB, SD/MMC, USB, SPI, I2C,
etc.

AST2400 SoC based machines :

- ``palmetto-bmc``         OpenPOWER Palmetto POWER8 BMC

AST2500 SoC based machines :

- ``ast2500-evb``          Aspeed AST2500 Evaluation board
- ``romulus-bmc``          OpenPOWER Romulus POWER9 BMC
- ``witherspoon-bmc``      OpenPOWER Witherspoon POWER9 BMC
- ``sonorapass-bmc``       OCP SonoraPass BMC
- ``swift-bmc``            OpenPOWER Swift BMC POWER9

AST2600 SoC based machines :

- ``ast2600-evb``          Aspeed AST2600 Evaluation board (Cortex A7)
- ``tacoma-bmc``           OpenPOWER Witherspoon POWER9 AST2600 BMC

Supported devices
-----------------

 * SMP (for the AST2600 Cortex-A7)
 * Interrupt Controller (VIC)
 * Timer Controller
 * RTC Controller
 * I2C Controller
 * System Control Unit (SCU)
 * SRAM mapping
 * X-DMA Controller (basic interface)
 * Static Memory Controller (SMC or FMC) - Only SPI Flash support
 * SPI Memory Controller
 * USB 2.0 Controller
 * SD/MMC storage controllers
 * SDRAM controller (dummy interface for basic settings and training)
 * Watchdog Controller
 * GPIO Controller (Master only)
 * UART
 * Ethernet controllers
 * Front LEDs (PCA9552 on I2C bus)
 * LPC Peripheral Controller (a subset of subdevices are supported)


Missing devices
---------------

 * Coprocessor support
 * ADC (out of tree implementation)
 * PWM and Fan Controller
 * Slave GPIO Controller
 * Super I/O Controller
 * Hash/Crypto Engine
 * PCI-Express 1 Controller
 * Graphic Display Controller
 * PECI Controller
 * MCTP Controller
 * Mailbox Controller
 * Virtual UART
 * eSPI Controller
 * I3C Controller

Boot options
------------

The Aspeed machines can be started using the ``-kernel`` option to
load a Linux kernel or from a firmware. Images can be downloaded from
the OpenBMC jenkins :

   https://jenkins.openbmc.org/job/ci-openbmc/lastSuccessfulBuild/distro=ubuntu,label=docker-builder

or directly from the OpenBMC GitHub release repository :

   https://github.com/openbmc/openbmc/releases

The image should be attached as an MTD drive. Run :

.. code-block:: bash

  $ qemu-system-arm -M romulus-bmc -nic user \
	-drive file=obmc-phosphor-image-romulus.static.mtd,format=raw,if=mtd -nographic

Options specific to Aspeed machines are :

 * ``execute-in-place`` which emulates the boot from the CE0 flash
   device by using the FMC controller to load the instructions, and
   not simply from RAM. This takes a little longer.

 * ``fmc-model`` to change the FMC Flash model. FW needs support for
   the chip model to boot.

 * ``spi-model`` to change the SPI Flash model.

For instance, to start the ``ast2500-evb`` machine with a different
FMC chip and a bigger (64M) SPI chip, use :

.. code-block:: bash

  -M ast2500-evb,fmc-model=mx25l25635e,spi-model=mx66u51235f