better elf errors

Author: icewind1991

espflash/src/error.rs

@@ -18,8 +18,8 @@ pub enum Error {
         code(espflash::invalid_elf),
         help("Try running `cargo clean` and rebuilding the image")
     )]
-    InvalidElf,
-    #[error("Supplied elf image can not be ran from ram")]
+    InvalidElf(#[from] ElfError),
+    #[error("Supplied elf image can not be ran from ram as it includes segments mapped to rom addresses")]
     #[diagnostic(
         code(espflash::not_ram_loadable),
         help("Either build the binary to be all in ram or remove the `--ram` option to load the image to flash")
@@ -153,6 +153,7 @@ impl From<binread::Error> for Error {
 #[derive(Copy, Clone, Debug, Error, Diagnostic)]
 #[allow(dead_code)]
 #[repr(u8)]
+#[non_exhaustive]
 pub enum RomError {
     #[error("Invalid message received")]
     #[diagnostic(code(espflash::rom::invalid_message))]
@@ -274,3 +275,13 @@ impl PartitionTableError {
 fn pos_to_offset(pos: Position) -> SourceOffset {
     (pos.byte() as usize + 1).into()
 }
+
+#[derive(Debug, Error)]
+#[error("{0}")]
+pub struct ElfError(&'static str);
+
+impl From<&'static str> for ElfError {
+    fn from(err: &'static str) -> Self {
+        ElfError(err)
+    }
+}

espflash/src/flasher.rs

@@ -5,7 +5,7 @@ use strum_macros::Display;
 use std::thread::sleep;
 
 use crate::elf::RomSegment;
-use crate::error::{ConnectionError, ResultExt};
+use crate::error::{ConnectionError, ElfError, ResultExt};
 use crate::{
     chip::Chip, connection::Connection, elf::FirmwareImage, encoder::SlipEncoder, error::RomError,
     Error, PartitionTable,
@@ -469,7 +469,7 @@ impl Flasher {
     ///
     /// Note that this will not touch the flash on the device
     pub fn load_elf_to_ram(&mut self, elf_data: &[u8]) -> Result<(), Error> {
-        let image = FirmwareImage::from_data(elf_data).map_err(|_| Error::InvalidElf)?;
+        let image = FirmwareImage::from_data(elf_data).map_err(ElfError::from)?;
 
         let mut target = self.chip.ram_target();
         target.begin(&mut self.connection, &image).flashing()?;
@@ -500,7 +500,7 @@ impl Flasher {
         bootloader: Option<Vec<u8>>,
         partition_table: Option<PartitionTable>,
     ) -> Result<(), Error> {
-        let mut image = FirmwareImage::from_data(elf_data).map_err(|_| Error::InvalidElf)?;
+        let mut image = FirmwareImage::from_data(elf_data).map_err(ElfError::from)?;
         image.flash_size = self.flash_size();
 
         let mut target = self.chip.flash_target(self.spi_params);