nrf5x: Add nice!nano board#963
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| .{ .tag = .flash, .offset = 0x00026000, .length = 0x100000 - 0x26000, .access = .rx }, | ||
| .{ .tag = .ram, .offset = 0x20002800, .length = 0x40000 - 0x2800, .access = .rwx }, |
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Where are you getting these? This is your attempts to not trample the uf2 bootloader? Not sure if we'd want to add a separate target for if/when we want to flash directly. Is the ram allocation just for the softdevice? Does your uf2 bootloader fill that up?
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Yeah the ram offset was from my attempts to make it work. The 0x2800 is from #921 - this is ram reserved for softdevice. Now I discovered that for disabled softdevice it should start at 0x20000008 - MBR reserves 8 bytes for interrupt forwarding.
(Also with cpu.ram_vector_table = true it's not needed, interrupts work with ram starting at 0x20000000).
As for flash, 0x0000-0x1000 is MBR, then everything until 0x00026000 is reserved for softdevice (S140 6.1.1 in this case, different for other versions). Writing there breaks everything.
Many popular boards use this bootloader, I think there should be support for building uf2 for it without flashing actual softdevice binaries and allocating ram.
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Tested on an original nice!nano and a "promicro nrf52840" clone.
But this board is shipped with Adafruit UF2 bootloader which supports SoftDevice, so the flashing offsets are different.
Does it make sense to add it separately from #921?