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ucb-bar / chipyard

An Agile RISC-V SoC Design Framework with in-order cores, out-of-order cores, accelerators, and more
https://chipyard.readthedocs.io/en/stable/
BSD 3-Clause "New" or "Revised" License
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How to get more details about bootrom and how to set Rocketchip to boot from SPFlash specified address #1096

Closed StilluSmile closed 1 year ago

StilluSmile commented 2 years ago

Based on chipyard I generated a SoC with DRAM and SPIFlash, next I want to map this SoC to FPGA board. I will not use the JTAG interface for the time being, and directly read and load the executable file from the external flash. Note that there is a bootrom folder in the rocket-chip subdirectory. Is it possible to modify the starting address after reset by modifying the bootrom? Also, I would like to know if I place the executable at a certain address on the flash, how can I set the CPU to load and execute the executable from the above specified address. Looking forward to hearing from you~

jerryz123 commented 2 years ago

We recently added a feature to adjust the boot address. Add the following config fragment to your config

new testchipip.WithCustomBootPinAltAddr(<some_addr>) ++

The generated chip should have a single external IO called custom_boot or something. When that pin is asserted, the core will jump to <some_addr> instead of DRAM_BASE. This is intended to be useful for dynamically selecting boot address after tapeout (or after FPGA deployment).

To test this in RTL simulation, pass EXTRA_SIM_FLAGS="+custom_boot_pin=1 to the make command.

StilluSmile commented 2 years ago

ok，i will try it.

jerryz123 commented 1 year ago

closing due to inactivity, this works now.