Replace elf reading with xmas-elf

Author: tommythorn

Cargo.toml

@@ -32,12 +32,15 @@ num-traits = "*"
 num-derive = "*"
 wasm-timer = "0.2.5"
 log = "0.4.26"
+xmas-elf = "0.10.0"
 
 [dev-dependencies]
 libc = "0.2.155"
 termios = "0.3.3"
 getopts = "0.2"
 env_logger = "0.11.7"
+xmas-elf = "0.10.0"
+anyhow = "1.0.98"
 
 [[example]]
 name = "sim"

examples/sim/main.rs

@@ -4,6 +4,7 @@ mod popup_terminal;
 
 use crate::dummy_terminal::DummyTerminal;
 use crate::popup_terminal::PopupTerminal;
+use anyhow::anyhow;
 use getopts::Options;
 use simmerv::Emulator;
 use simmerv::terminal::Terminal;
@@ -28,7 +29,7 @@ fn get_terminal(terminal_type: &TerminalType) -> Box<dyn Terminal> {
     }
 }
 
-fn main() -> std::io::Result<()> {
+fn main() -> anyhow::Result<()> {
     env_logger::init();
 
     let args: Vec<String> = env::args().collect();
@@ -100,8 +101,15 @@ fn main() -> std::io::Result<()> {
         TerminalType::PopupTerminal
     };
 
+    let mut symbols = std::collections::BTreeMap::new();
     let mut emulator = Emulator::new(get_terminal(&terminal_type));
-    emulator.setup_program(elf_contents);
+    emulator
+        .setup_program(&elf_contents, 0x80000000, &mut symbols)
+        .map_err(|e| anyhow!(e))?;
+    if let Some(addr) = symbols.get("tohost") {
+        emulator.tohost_addr = *addr;
+    }
+
     emulator.setup_filesystem(fs_contents);
     if has_dtb {
         emulator.setup_dtb(&dtb_contents);

src/cpu.rs

@@ -282,11 +282,15 @@ impl Cpu {
         }
     }
 
-    fn handle_exception(&mut self, exc: &Exception) {
-        // XXX If we pass in the address we don't need
-        // self.pc, but that requires us to call handle exception from a centrol
-        // location with access to the pc.
-        self.handle_trap(exc, self.insn_addr, false);
+    fn handle_exception(&mut self, exception: &Exception) {
+        if matches!(exception.trap, Trap::IllegalInstruction) {
+            log::info!(
+                "Illegal instruction {:016x} {:x}",
+                self.insn_addr,
+                self.insn
+            );
+        }
+        self.handle_trap(exception, self.insn_addr, false);
     }
 
     #[allow(clippy::similar_names, clippy::too_many_lines)]
@@ -557,13 +561,11 @@ impl Cpu {
                     return illegal;
                 }
 
-                let mode = (value >> SATP_MODE_SHIFT) & SATP_MODE_MASK;
-                if mode != 0
-                    && mode != SatpMode::Sv39 as u64
-                    && mode != SatpMode::Sv48 as u64
-                    && mode != SatpMode::Sv57 as u64
-                {
-                    log::warn!("Illegal SATP mode {mode:02x}");
+                if !matches!(
+                    FromPrimitive::from_u64((value >> SATP_MODE_SHIFT) & SATP_MODE_MASK),
+                    Some(SatpMode::Bare | SatpMode::Sv39 | SatpMode::Sv48 | SatpMode::Sv57)
+                ) {
+                    log::warn!("wrote illegal value {value:x} to satp");
                     return illegal;
                 }
             }
@@ -1822,7 +1824,7 @@ const INSTRUCTIONS: [Instruction; INSTRUCTION_NUM] = [
             if word == 0x0100000f {
                 // Nothing to do here, but it would be interesting to see
                 // it used.
-                log::trace!("pause");
+                log::trace!("pause isn't yet implemented");
             }
             // Fence memory ops (we are currently TSO already)
             Ok(())

src/csr.rs

@@ -18,15 +18,16 @@ pub enum Csr {
     Sstatus = 0x100,
     Sedeleg = 0x102,
     Sideleg = 0x103,
+    Scounteren = 0x106,
     Sie = 0x104,
     Stvec = 0x105,
-    Csr106 = 0x106,
     Sscratch = 0x140,
     Sepc = 0x141,
     Scause = 0x142,
     Stval = 0x143,
     Sip = 0x144,
     Satp = 0x180,
+
     Mstatus = 0x300,
     Misa = 0x301,
     Medeleg = 0x302,
@@ -167,6 +168,7 @@ pub const fn legal(csr: Csr) -> bool {
             | Csr::Sedeleg
             | Csr::Sepc
             | Csr::Sideleg
+            | Csr::Scounteren
             | Csr::Sie
             | Csr::Sip
             | Csr::Sscratch
@@ -182,7 +184,6 @@ pub const fn legal(csr: Csr) -> bool {
             | Csr::Ustatus
             | Csr::Utval
             | Csr::Utvec
-            | Csr::Csr106
             | Csr::Csr306
     )
 }