diff --git a/Board-STM32F429.md b/Board-STM32F429.md index e4f5059..bbb0fa0 100644 --- a/Board-STM32F429.md +++ b/Board-STM32F429.md @@ -23,7 +23,7 @@ Similarly, bare MicroPython does not initialise any of the other peripherals and The chip's 256KiB RAM is made up of 192KiB contiguous general-purpose SRAM and a separate 64KiB core-coupled memory. MicroPython reserves the 64KiB for caching flash writes. MicroPython uses 80KiB for the stack, 112KiB for the statics/heap. That stack/heap split results in quite a generous stack which you're unlikely to use unless you use deeply nested calls or heavy recursion, but is easily tuned by modifying `_heap_end` in the [linker script](https://github.com/micropython/micropython/blob/761e4c7f/stmhal/boards/stm32f429.ld). -The chip's 2MiB flash is made up of various pages of different sizes, split across two non-contiguous 1MiB blocks, and only the first 64KiB of any page can be used. By default that leaves 112KiB available before filesystem overheads, ~95KiB after overheads. It's pretty simple to [increase this](https://forum.micropython.org/viewtopic.php?t=777#p4491) to 304KiB (before overheads) by enabling the non-contiguous flash features in `storage.c`, rebuilding, reflashing, then carrying out a [factory reset](http://docs.micropython.org/en/v1.9/pyboard/pyboard/tutorial/reset.html) to enlarge the filesystem. It should be possible to increase this by another 64KiB by using the first half of sector 5; haven't managed to get this working like it should just yet though. +The chip's 2MiB flash is made up of various pages of different sizes, split across two non-contiguous 1MiB blocks, and only the first 64KiB of any page can be used. By default that leaves 112KiB available before filesystem overheads, ~95KiB after overheads. It's pretty simple to [increase this](https://forum.micropython.org/viewtopic.php?t=777#p4491) to 304KiB (before overheads) by enabling the [non-contiguous flash features](https://gist.github.com/zwlp/bcfda08018c0c80a948a99809fc7cc4e) in `storage.c`, rebuilding, reflashing, then carrying out a [factory reset](http://docs.micropython.org/en/v1.9/pyboard/pyboard/tutorial/reset.html) to enlarge the filesystem. It should be possible to increase this by another 64KiB by using the first half of sector 5; haven't managed to get this working like it should just yet though. On the mini-USB, the STLinkV2 offers a virtual mass storage device plus a virtual serial port that's connected to the target's USART1. On the micro-USB, MicroPython adds a its own mass storage device and a .second virtual serial port which is emulated and connected to the REPL.