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+BSP for the Raspberry Pi ARM board
+This is a basic port that should work on either Model A or Model B.
+It currently supports the following devices:
+ o Console using the PL011 UART0
+ The console driver only works with polled mode right now,
+ the interrupt code is there, but it does not work yet.
+ The console driver is currently hardcoded at 115k 8N1
+ o Clock uses the internal ARM timer
+ The Raspberry Pi can be overclocked through the config.txt file, this
+ would affect the duration of the clock tick.
+ o Benchmark timer reads the lower 32 bit GPU timer register
+To run an RTEMS binary, it must be stripped and loaded on the SD card along with
+the following files:
+ kernel.img ( the RTEMS binary, you can change the name in config.txt )
+These files can be obtained from a Linux installation image, or from here:
+I used an old 256MB SD card to boot RTEMS.
+Much more information about the SD card file and bootloader can be found here:
+The linker script is set up for 128MB, so it can be used with a GPU/ARM split
+The bootloader that is used on the SD card determines the split of RAM between the
+ARM and the GPU. It might make sense to adjust the GPU/ARM memory split to give
+more memory to RTEMS, especially on a 512MB board.
+ It would be nice to get support in the BSP for the following:
+ o SD card
+ o USB and USB 10/100 network chip on Model B
+ o SPI
+ o GPIO
+ o ARM MMU
+ o Graphics console
+ o Sound
+Credits and links:
+ There is a wealth of code and information to reference on the raspberrypi.org bare metal forums:
+ I found information about how to program the timers, interrupts, and UART 0
+ from the examples provided by:
+ David Welch:
+ The readme file at his github repository has valuable information about connecting a UART cable, JTAG etc.
+ Steve Bate:
+ Steve provided a port of the Chibios RTOS to the raspberry Pi
+ James Walmsley:
+ James ported FreeRTOS to the raspberry Pi.