PXA3xx Boot ROM Reference Manual - Marvell

PXA3xx Processors and Tavor ProcessorBoot ROM Reference Manual7.3.1 GPIO PackagesThe GPIO packages allow users to set any memory space or address space to a preferred value,thereby allowing GPIOs to be configured by the Boot ROM.The header ID for this package is0x4750494F, which represents GPIO in ASCII. The number of pairs to set is defined by NumGpios,as shown in the code below.OPT_GPIO_SET:WTP_RESERVED_AREA_HEADER WRAH;unsigned int NumGpios;GPIO_DEF:volatile int *Addr;unsigned int Value;GPIOs can now be configured by the Boot ROM. For example, a GPIO is required to be set high in aplatform design using the PXA31x processor. The appropriate GPIO is selected - GPIO, in thisexample. The GPIO package layout is shown below. This information is added to the end of theNTIM header after the image details.Reserved Data:0x4F505448 // Package structure identifier0x00000002 // number of packages, note must include termination package0x4750494f // GPIO package0x00000024// size of GPIO package (a package has address and data, known as a pair.Each Pair is 8 bytes - 4 bytes address and 4 bytes data)0x00000003// number of pairs (in this example there are 3 data pairs below)0x40e104d0// register address (MFPR for GPIO)0x00000840// data0x40e00014// register address (GPDR2)0x00001000// data (set GPIO as output)0x40e00020// register address (GPSR)0x00001000// data (set GPIO as high)0x5465726D // Termination package0x000000087.3.2 UART/USB Protocol PackagesThe UART/USB Protocol Packages allow overriding default USB and UART connection settings.The identifier for this package is 0x55415254 (for UART) or 0x00555342 (for USB). The portmay also select as appropriate one of the following IDs:FFIDENTIFIER:ALTIDENTIFIER:DIFFIDENTIFIER:0x000046460x00414C540x4469666612345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758Doc. No. MV-S301208-00 Rev. - PUBLIC RELEASE Copyright © 2010 MarvellPage 76