diff --git a/arch/x86/zefi/zefi.py b/arch/x86/zefi/zefi.py
index 2f9c3482bb4c..b98419f8a49e 100755
--- a/arch/x86/zefi/zefi.py
+++ b/arch/x86/zefi/zefi.py
@@ -117,7 +117,7 @@ def build_elf(elf_file, include_dirs):
         includes.extend(["-I", include_dir])
     cmd = ([args.compiler, "-shared", "-Wall", "-Werror", "-I."] + includes +
            ["-fno-stack-protector", "-fpic", "-mno-red-zone", "-fshort-wchar",
-            "-Wl,-nostdlib", "-T", ldscript, "-o", "zefi.elf", cfile])
+            "-Wl,-nostdlib", "-nostartfiles", "-T", ldscript, "-o", "zefi.elf", cfile])
     verbose(" ".join(cmd))
     subprocess.run(cmd, check = True)
 
diff --git a/modules/cmsis-dsp/CMakeLists.txt b/modules/cmsis-dsp/CMakeLists.txt
index 2a0924cc25cc..8332ad2006f9 100644
--- a/modules/cmsis-dsp/CMakeLists.txt
+++ b/modules/cmsis-dsp/CMakeLists.txt
@@ -19,6 +19,9 @@ if(CONFIG_CMSIS_DSP)
     ${cmsis_glue_path}/CMSIS/Core/Include
   )
 
+  # Define ZEPHYR_INCLUDE_TOOLCHAIN_STDINT_H_ to avoid using Zephyr's stdint.h
+  zephyr_library_compile_definitions(ZEPHYR_INCLUDE_TOOLCHAIN_STDINT_H_)
+
   # Global Feature Definitions
   zephyr_library_compile_definitions_ifdef(CONFIG_CMSIS_DSP_NEON                  ARM_MATH_NEON)
   zephyr_library_compile_definitions_ifdef(CONFIG_CMSIS_DSP_NEON_EXPERIMENTAL     ARM_MATH_NEON_EXPERIMENTAL)
diff --git a/tests/lib/c_lib/common/testcase.yaml b/tests/lib/c_lib/common/testcase.yaml
index 4d184b9536f5..4fb1e73538ea 100644
--- a/tests/lib/c_lib/common/testcase.yaml
+++ b/tests/lib/c_lib/common/testcase.yaml
@@ -2,6 +2,9 @@ common:
   tags:
     - clib
   ignore_faults: true
+  arch_exclude:
+    # see #89839
+    - rx
   integration_platforms:
     - mps2/an385
 tests:
diff --git a/tests/lib/c_lib/thrd/testcase.yaml b/tests/lib/c_lib/thrd/testcase.yaml
index d236ed70445d..acc406d08c62 100644
--- a/tests/lib/c_lib/thrd/testcase.yaml
+++ b/tests/lib/c_lib/thrd/testcase.yaml
@@ -10,6 +10,9 @@ common:
     - arch
     - simulation
   filter: not CONFIG_NATIVE_APPLICATION
+  arch_exclude:
+    # see #89839
+    - rx
 tests:
   libraries.libc.c11_threads.minimal:
     tags: minimal_libc
diff --git a/tests/lib/cpp/libcxx/testcase.yaml b/tests/lib/cpp/libcxx/testcase.yaml
index 566a0d689d3c..37fa4ef3d5de 100644
--- a/tests/lib/cpp/libcxx/testcase.yaml
+++ b/tests/lib/cpp/libcxx/testcase.yaml
@@ -1,3 +1,7 @@
+common:
+  arch_exclude:
+    # see #89839
+    - rx
 tests:
   cpp.libcxx.glibcxx.newlib:
     filter: TOOLCHAIN_HAS_NEWLIB == 1