init

src/main.rs

@@ -0,0 +1,71 @@
+use aligned_vec::avec;
+use eyre::{OptionExt, bail};
+
+mod elf;
+mod emu;
+
+const PAGE_SIZE: usize = 4096;
+
+// 2 MiB
+const MEMORY_SIZE: usize = 2 << 21;
+
+fn main() -> eyre::Result<()> {
+    let content = std::fs::read(std::env::args().nth(1).unwrap()).unwrap();
+
+    let elf = elf::Elf { content };
+    let header = elf.header()?;
+
+    dbg!(&header);
+
+    let segments = elf.segments()?;
+
+    let mut mem = emu::Memory {
+        mem: avec![[PAGE_SIZE]| 0; MEMORY_SIZE],
+    };
+
+    for phdr in segments {
+        dbg!(&phdr);
+        match phdr.p_type {
+            // PT_NULL
+            0 => {}
+            // PT_LOAD
+            1 => {
+                if phdr.p_filesz > 0 {
+                    let contents = &elf
+                        .content
+                        .get((phdr.p_offset as usize)..)
+                        .ok_or_eyre("invalid offset")?
+                        .get(..(phdr.p_filesz as usize))
+                        .ok_or_eyre("invalid offset")?;
+
+                    mem.mem
+                        .get_mut((phdr.p_vaddr as usize)..)
+                        .ok_or_eyre("invalid offset")?
+                        .get_mut(..(phdr.p_filesz as usize))
+                        .ok_or_eyre("invalid offset")?
+                        .copy_from_slice(contents);
+                }
+            }
+            // PT_PHDR
+            6 => {}
+            // PT_GNU_EH_FRAME
+            1685382480 => {}
+            // PT_GNU_STACK
+            1685382481 => {}
+            // PT_RISCV_ATTRIBUTES
+            0x70000003 => {}
+            _ => bail!("unknown program header type: {}", phdr.p_type),
+        }
+    }
+
+    let start = header.e_entry;
+
+    let mut emu = emu::Emulator {
+        mem,
+        xreg: [0; 32],
+        pc: start,
+    };
+    emu.execute().unwrap();
+
+    Ok(())
+}