From 54be08afe44f1902f042d3228a1df4aa24f56a6c Mon Sep 17 00:00:00 2001 From: David Zwart Date: Wed, 3 Apr 2024 22:24:09 +0200 Subject: [PATCH] Update faq.adoc with memory.x definition helping hand --- docs/modules/ROOT/pages/faq.adoc | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/docs/modules/ROOT/pages/faq.adoc b/docs/modules/ROOT/pages/faq.adoc index 6b5e6d009..b5d702040 100644 --- a/docs/modules/ROOT/pages/faq.adoc +++ b/docs/modules/ROOT/pages/faq.adoc @@ -208,3 +208,24 @@ Tools like `cargo size` and `cargo nm` can tell you the size of any globals or o === For Max Stack Usage Check out link:https://github.com/Dirbaio/cargo-call-stack/[`cargo-call-stack`] for statically calculating worst-case stack usage. There are some caveats and inaccuracies possible with this, but this is a good way to get the general idea. See link:https://github.com/dirbaio/cargo-call-stack#known-limitations[the README] for more details. + +== The memory definition for my STM chip seems wrong, how do I define a `memory.x` file? + +It could happen that your project compiles, flashes but fails to run. The following situation can be true for your setup: + +The `memory.x` is generated automatically when enabling the `memory-x` feature on the `embassy-stm32` crate in the `Cargo.toml` file. +This, in turn, uses `stm32-metapac` to generate the `memory.x` file for you. Unfortunately, more often than not this memory definition is not correct. + +You can override this by adding your own `memory.x` file. Such a file could look like this: +``` +MEMORY +{ + FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 1024K + RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 320K +} + +_stack_start = ORIGIN(RAM) + LENGTH(RAM); +``` + +Please refer to the STM32 documentation for the specific values suitable for your board and setup. The STM32 Cube examples often contain a linker script `.ld` file. +Look for the `MEMORY` section and try to determine the FLASH and RAM sizes and section start.