rtic: rtfm based stm32f030 debug build causes relcation truncated error

here is an example project: https://gitlab.com/xnor/stm32f0308-disco-rust

If I build it without --release I get

target/thumbv6m-none-eabi/debug   /deps/libstm32f030-5466fdead1a18a6d.rlib(stm32f030-5466fdead1a18a6d.0.o): In function `WWDG':
      stm32f030.cgu-0.rs:(.text+0x0): relocation truncated to fit: R_ARM_THM_JUMP11 against symbol `DEFAULT_HANDLER' defined in .text.DEFAULT_HANDLER section in /home/alex/projects/modular/threshpan/target/thumbv6m-none-eabi/debug/deps/libcortex_m_rt-881d17200def560b.rlib(cortex_m_rt-881d17200def560b.0.o)

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 41 (4 by maintainers)

Commits related to this issue

Use far-ranged jumps for DH_TRAMPOLINE Fixes japaric/cortex-m-rtfm#42 Note that this will make all generated crates that target an armv6 device fail to compile unless they add a build script enablin... — committed to therealprof/svd2rust by jonas-schievink 7 years ago
[WIP] safe creation of `&'static mut` references This implements the "rooting" mechanism proposed in #47. However, it implements a `root` constructor function instead of list of `roots` values as ori... — committed to rtic-rs/rtic by japaric 7 years ago
Merge pull request #42 from AfoHT/replacetravis Replace Travis with Github Actions — committed to rtic-rs/rtic by korken89 4 years ago

Most upvoted comments

@Samonitari Yes, thumb1 has b instrunction, but we need b.w which is 32bit T2 instruction. There is no way to encode such instruction on Cortex-M0. So there is no bug in LLVM.

pftbest on Sep 5, 2017

@japaric I figured out what the problem is… svd2rust

Seemingly the default CPU model for the armv6-m architecture is broken. I tried various options including using the -mcpu=cortex-m0 and -mcpu=cortex-m3 options on the generated assembly and the latter automatically changes branches where the target doesn’t fit into the available 2 bytes into the 4 bytes form of the branch while the default model and -mcpu=cortex-m0 (which actually might be the default model) keeps it as-is causing the linker to barf.

However, if I explicitly change the short branch in the code emitted by svd2rust into the long form, it’ll happily compile and link the binaries, cf.:

diff --git a/src/svd.rs b/src/svd.rs
index 149a3ed..8bfc3f2 100644
--- a/src/svd.rs
+++ b/src/svd.rs
@@ -11,7 +11,7 @@ pub mod interrupt {
         "
                 .thumb_func
                 DH_TRAMPOLINE:
-                    b DEFAULT_HANDLER
+                    bl DEFAULT_HANDLER
                 "
     );
     #[cfg(feature = "rt")]

@x37v Can you with the above change on your code?

therealprof on Aug 31, 2017