wsong83
commented
7 years ago Hello Furkan Turan,
The boot procedure is indeed different with v2 because the upstream Linux has changed. It is still a BBL but in a separate submodule. The BBL in v3 needs to be compiled into the same ELF with the kernel. So BBL no long load Linux kernel from SD but from a location in physical memory.
I think you can compare the bootloader submodule with the riscv-pk from the v3 lowrisc-chip repo. The bootloader submodule is revised from that version of riscv-pk. The actual revision is roughly the same for the v2 except for the change in loading Linux kernel.
There is a script (does mentioned in tutorial) in riscv-tools: riscv-tools/make_root.sh It has all the commands needed to regenerate a BBL+Kernel image.
Hope this is helpful, Wei
On 09/02/2017 13:46, Furkan Turan wrote:
Hello,
I tested the v2 branch previously for my project. It is documented well on the lowrisc.org. I ported the design back to ZedBoard, making it use the half of ARM's DDR memory, and I provided the UART and SD card via PMODs. I followed the steps as described: built the boot.c, and ./bbl, provided the Linux kernel. Everything works.
I want to try the v3 branch as well. It interests me as it has a different boot mechanism than BBL, and on my project I need to work with a custom bootloader. (I am also trying to follow the Coreboot port progress) However, I didn't understand how to use the bootloader in this branch. It has an own sub-repository; however no description/readme.
Can you please, briefly explain how to use the bootloader of the v3 branch to boot Linux?
Kind Regards,
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furkanturan
Hello,
I tested the v2 branch previously for my project. It is documented well on the lowrisc.org. I ported the design back to ZedBoard, making it use the half of ARM's DDR memory, and I provided the UART and SD card via PMODs. I followed the steps as described: built the boot.c, and ./bbl, provided the Linux kernel. Everything works.
I want to try the v3 branch as well. It interests me as it has a different boot mechanism than BBL, and on my project I need to work with a custom bootloader. (I am also trying to follow the Coreboot port progress) However, I didn't understand how to use the bootloader in this branch. It has an own sub-repository; however no description/readme.
Can you please, briefly explain how to use the bootloader of the v3 branch to boot Linux?
Kind Regards,