From 4c63b7a21a6fae7f7e30689a4644fb8c6a19b28b Mon Sep 17 00:00:00 2001
From: Marco Thomas <github@marcothms.de>
Date: Wed, 28 May 2025 15:59:37 +0900
Subject: [PATCH] ft: add dump flag

---
 README.md     | 11 ++++++-----
 src/disasm.rs | 17 +++++++++++++----
 src/main.rs   |  6 +++++-
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 8f2623b..7f9d8f3 100644
--- a/README.md
+++ b/README.md
@@ -1,11 +1,11 @@
 # minix-8086-rs
 
-minix-8086-rs is a Rust-based toolchain for analyzing and interpreting 16-bit 8086 binaries, made with the intention of interpreting binaries compiled for MINIX.
+minix-8086-rs is a Rust-based toolchain for analyzing and interpreting 16-bit 8086 binaries, made with the intention of interpreting binaries compiled for MINIX 1.x.
 
 It includes:
-- 📦 a.out Parser: Parses legacy MINIX executables.
+- 📦 a.out Parser: Parses legacy MINIX 1.x executables.
 - 🛠 8086 Disassembler: Parses 16-bit instructions into an IR and prints them in a `objdump(1)`-style fashion.
-- 💻 8086 Interpreter: Interprets the 8086 instructions, i.e., the MINIX binary.
+- 💻 8086 Interpreter: Interprets the 8086 instructions, i.e., the MINIX 1.x binary.
 
 ## Usage
 
@@ -21,7 +21,7 @@ cargo run -- --help
 
 Run with debug output:
 ```
-RUST_LOG=debug cargo run -- interpret -p ./a.out
+RUST_LOG=debug cargo run -- interpret -p ./a.out 2>&1 | less
 ```
 
 CLI Options:
@@ -38,8 +38,9 @@ Commands:
                                                                                        
 Options:                                                                               
   -p, --path <PATH>  Path of the binary                                                
+  -d, --dump         Dump progress of disassembly, in case of encountering an error    
   -h, --help         Print help                                                        
-  -V, --version      Print version                                                     
+  -V, --version      Print version
 ```
 
 ## Status
diff --git a/src/disasm.rs b/src/disasm.rs
index 358fb39..bca0073 100644
--- a/src/disasm.rs
+++ b/src/disasm.rs
@@ -43,7 +43,7 @@ impl fmt::Display for DisasmError {
             DisasmError::IoError(msg) => write!(f, "{}", msg),
             DisasmError::OpcodeUndefined(opcode) => write!(
                 f,
-                "Error (Undefined Opcode). '{:#04x} is considered undefined by the Spec",
+                "Error (Undefined Opcode). '{:#04x} is considered undefined by the Spec for 8086.\nMaybe you are trying to interpret a x86 binary?\nAborting to stop misinterpretation of following instructions.",
                 opcode
             ),
             DisasmError::IllegalGroupMnemonic(group, mnemonic) => write!(
@@ -106,7 +106,7 @@ impl Disassembler {
 
     /// Start the disassmble and allow for some error handling wrapped around
     /// the actual decoding function.
-    pub fn disassemble(&mut self) -> Result<Vec<Instruction>, DisasmError> {
+    pub fn disassemble(&mut self, dump: bool) -> Result<Vec<Instruction>, DisasmError> {
         let is_ok = self.decode_instructions();
 
         // a.out pads the text section to byte align, so the fasely interpreted
@@ -126,7 +126,16 @@ impl Disassembler {
                     Ok(instructions)
                 }
                 _ => {
-                    println!("Encountered error during disassembly: {e}");
+                    if dump {
+                        self.instructions.iter().for_each(|i| println!("{i}"));
+                        println!(
+                            "Encountered error during disassembly, but this is the process so far...\n{e}\nRun with RUST_LOG=debug for furhter information."
+                        );
+                    } else {
+                        println!(
+                            "Encountered error during disassembly.\nRun with --dump to get sucessfully parsed instructions.\n{e}"
+                        );
+                    }
                     Err(e)
                 }
             },
@@ -485,7 +494,7 @@ impl Disassembler {
             // additional raw bytes will be pushed by parse functions
             self.instruction.raw.push(opcode);
 
-            log::debug!("Parsing next opcode with opcode: {opcode:#04}");
+            log::debug!("Parsing next opcode with opcode: {opcode:#04x}");
             self.instruction.opcode = match opcode {
                 0x00 => modrm_8b_register!(self, ADD_FromReg),
                 0x01 => modrm_16b_register!(self, ADD_FromReg),
diff --git a/src/main.rs b/src/main.rs
index 02d0933..b1fe78e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,6 +28,10 @@ struct Args {
     /// Path of the binary
     #[arg(short, long, global = true)]
     path: Option<String>,
+
+    /// Dump progress of disassembly, in case of encountering an error.
+    #[arg(short, long, global = true, action)]
+    dump: bool,
 }
 
 fn main() {
@@ -39,7 +43,7 @@ fn main() {
     match args.command {
         Command::Disasm => {
             let mut disasm = Disassembler::new(&args);
-            let instructions = disasm.disassemble();
+            let instructions = disasm.disassemble(args.dump);
             match instructions {
                 Ok(instrs) => instrs.iter().for_each(|i| println!("{i}")),
                 _ => {}