Remove analyze_vector_table() as the ELF file has that information.

src/cortexm.rs

@@ -46,8 +46,10 @@ pub fn subroutine_eq(addr1: u32, addr2: u32) -> bool {
 /// The contents of the vector table
 #[derive(Debug)]
 pub struct VectorTable {
-    // entry 0
+    // entry 0: Initial SP
     pub initial_stack_pointer: u32,
+    // entry 1: Reset vector
+    pub reset: u32,
     // entry 3: HardFault handler
     pub hard_fault: u32,
 }

src/elf.rs

@@ -27,11 +27,7 @@ pub struct Elf<'file> {
 }
 
 impl<'file> Elf<'file> {
-    pub fn parse(
-        elf_bytes: &'file [u8],
-        elf_path: &'file Path,
-        reset_fn_address: u32,
-    ) -> Result<Self, anyhow::Error> {
+    pub fn parse(elf_bytes: &'file [u8], elf_path: &'file Path) -> Result<Self, anyhow::Error> {
         let elf = ObjectFile::parse(elf_bytes)?;
 
         let live_functions = extract_live_functions(&elf)?;
@@ -42,7 +38,7 @@ impl<'file> Elf<'file> {
 
         let debug_frame = extract_debug_frame(&elf)?;
 
-        let symbols = extract_symbols(&elf, reset_fn_address)?;
+        let symbols = extract_symbols(&elf, vector_table.reset)?;
 
         Ok(Self {
             elf,
@@ -149,11 +145,12 @@ fn extract_vector_table(elf: &ObjectFile) -> anyhow::Result<cortexm::VectorTable
         .chunks_exact(4)
         .map(|chunk| u32::from_le_bytes(chunk.try_into().unwrap()));
 
-    if let (Some(initial_stack_pointer), Some(_reset), Some(_third), Some(hard_fault)) =
+    if let (Some(initial_stack_pointer), Some(reset), Some(_third), Some(hard_fault)) =
         (words.next(), words.next(), words.next(), words.next())
     {
         Ok(cortexm::VectorTable {
             initial_stack_pointer,
+            reset,
             hard_fault,
         })
     } else {

src/main.rs

@@ -60,10 +60,9 @@ fn run_target_program(elf_path: &Path, chip_name: &str, opts: &cli::Opts) -> any
     core.reset_and_halt(TIMEOUT)?;
 
     // gather information
-    let (stack_start, reset_fn_address) = analyze_vector_table(core)?;
     let elf_bytes = fs::read(elf_path)?;
-    let elf = &Elf::parse(&elf_bytes, elf_path, reset_fn_address)?;
-    let target_info = TargetInfo::new(elf, memory_map, probe_target, stack_start)?;
+    let elf = &Elf::parse(&elf_bytes, elf_path)?;
+    let target_info = TargetInfo::new(elf, memory_map, probe_target)?;
 
     // install stack canary
     let canary = Canary::install(core, &target_info, elf, opts.measure_stack)?;
@@ -197,17 +196,6 @@ fn flashing_progress() -> flashing::FlashProgress {
     })
 }
 
-/// Read stack-pointer and reset-handler-address from the vector table.
-///
-/// Assumes that the target was reset-halted.
-///
-/// Returns `(stack_start: u32, reset_fn_address: u32)`
-fn analyze_vector_table(core: &mut Core) -> anyhow::Result<(u32, u32)> {
-    let mut ivt = [0; 2];
-    core.read_32(0, &mut ivt[..])?;
-    Ok((ivt[0], ivt[1]))
-}
-
 fn start_program(core: &mut Core, elf: &Elf) -> anyhow::Result<()> {
     log::debug!("starting device");
 

src/target_info.rs

@@ -33,7 +33,6 @@ impl TargetInfo {
         elf: &Elf,
         memory_map: Vec<MemoryRegion>,
         probe_target: probe_rs::Target,
-        stack_start: u32,
     ) -> anyhow::Result<Self> {
         let active_ram_region =
             extract_active_ram_region(&probe_target, elf.vector_table.initial_stack_pointer);
@@ -46,7 +45,7 @@ impl TargetInfo {
             memory_map,
             probe_target,
             stack_info,
-            stack_start,
+            stack_start: elf.vector_table.initial_stack_pointer,
         })
     }
 }