In functional mode, if no valid image
header is found in the predefined SDF location, the bootloader will enter the SPI
based bootloading mode.
This
involves the following steps:
- Pinmux the SPI pins - [SPI_MOSI: Ball R8, SPI_MISO: Ball P5,
SPI_CLK: Ball R9, SPI_CS_N: Ball R7 and SPI_HOST_INTR: Ball P6 of AWR2243 device]
- Follows the “Communication Protocol” as defined in the Radar
Interface Control document to communicate with an external host to receive the
images to be loaded as message packets over SPI.
- Once the load of all images is complete, the patches to the ROM
get applied and then the functional firmware begins execution that could then
receive control API commands over SPI and send out the data over the high speed
interfaces (LVDS/CSI2).
The
handshake with the external host is as depicted in Figure 2-4.