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diff --git a/board/imgtec/xilfpga/README b/board/imgtec/xilfpga/README new file mode 100644 index 0000000000..ac19d485d4 --- /dev/null +++ b/board/imgtec/xilfpga/README @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2016, Imagination Technologies Ltd. + * + * Zubair Lutfullah Kakakhel, Zubair.Kakakhel@imgtec.com + */ + +MIPSfpga +======================================= + +MIPSfpga is an FPGA based development platform by Imagination Technologies +As we are dealing with a MIPS core instantiated on an FPGA, specifications +are fluid and can be varied in RTL. + +The example project provided by IMGTEC runs on the Nexys4DDR board by +Digilent powered by the ARTIX-7 FPGA by Xilinx. Relevant details about +the example project and the Nexys4DDR board: + +- microAptiv UP core m14Kc +- 50MHz clock speed +- 128Mbyte DDR RAM at 0x0000_0000 +- 8Kbyte RAM at 0x1000_0000 +- axi_intc at 0x1020_0000 +- axi_uart16550 at 0x1040_0000 +- axi_gpio at 0x1060_0000 +- axi_i2c at 0x10A0_0000 +- custom_gpio at 0x10C0_0000 +- axi_ethernetlite at 0x10E0_0000 +- 8Kbyte BootRAM at 0x1FC0_0000 +- 16Mbyte QPI at 0x1D00_0000 + +Boot protocol: +-------------- + +The BootRAM is a writeable "RAM" in FPGA at 0x1FC0_0000. +This is for easy reprogrammibility via JTAG. + +DDR initialization is already handled by a HW IP block. + +When the example project bitstream is loaded, the cpu_reset button +needs to be pressed. + +The bootram initializes the cache and axi_uart +Then checks if there is anything non 0xffff_ffff at location 0x1D40_0000 + +If there is, then that is considered as u-boot. u-boot is copied from +0x1D40_0000 to memory and the bootram jumps into u-boot code. + +At this point, the board is ready to load the Linux kernel + buildroot initramfs + +This can be done in multiple ways: + +1- JTAG load the binary and jump into it. +2- Load kernel stored in the QSPI flash at 0x1D80_0000 +3- Load uImage via tftp. Ethernet works in u-boot. + e.g. env set server ip 192.168.154.45; dhcp uImage; bootm |