don't overwrite partition table with bootloader config

1 files changed, 7 insertions, 4 deletions

diff --git a/src/main.rs b/src/main.rs
index c55c426..2b3981d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -147,14 +147,16 @@ fn write_mbr(file: &mut File) -> anyhow::Result<()> {
     let mut cmdline_buf = Vec::new();
     cmdline_file.read_to_end(&mut cmdline_buf)?;
 
-    let kernel_offset = buf
+    let kernel_offset: u32 = buf
         .windows(kernel_buf.len())
         .position(|window| window == kernel_buf)
-        .expect("can't find kernel (/vmlinuz) on boot partition");
-    let cmdline_offset = buf
+        .expect("can't find kernel (/vmlinuz) on boot partition")
+        .try_into()?;
+    let cmdline_offset: u32 = buf
         .windows(cmdline_buf.len())
         .position(|window| window == cmdline_buf)
-        .expect("can't find cmdline (/cmdline.txt) on boot partition");
+        .expect("can't find cmdline (/cmdline.txt) on boot partition")
+        .try_into()?;
 
     let kernel_lba = kernel_offset + 2048;
     let cmdline_lba = cmdline_offset + 2048;
@@ -162,6 +164,7 @@ fn write_mbr(file: &mut File) -> anyhow::Result<()> {
     let mut bootloader_params = Vec::new();
     bootloader_params.extend_from_slice(&kernel_lba.to_le_bytes());
     bootloader_params.extend_from_slice(&cmdline_lba.to_le_bytes());
+    eprintln!("{}", bootloader_params.len());
 
     let mut bootloader_file = File::open("boot.bin")?;
     let mut bootloader_buf = Vec::new();