Update redox-initfs and use the initfs_size header field instead of INITFS_LENGTH

Cargo.lock

@@ -104,7 +104,7 @@ dependencies = [
 [[package]]
 name = "redox-initfs"
 version = "0.1.0"
-source = "git+https://gitlab.redox-os.org/redox-os/redox-initfs.git#89b8fb8984cf96c418880b7dcd9ce3d6afc3f71c"
+source = "git+https://gitlab.redox-os.org/redox-os/redox-initfs.git#7dd9b2e84d983a444518218f3ec74d3e9ac900b3"
 dependencies = [
  "plain",
 ]

Cargo.toml

@@ -12,7 +12,7 @@ crate-type = ["staticlib"]
 [dependencies]
 hashbrown = { version = "0.14", default-features = false, features = ["inline-more"] }
 linked_list_allocator = "0.10"
-redox-initfs = { git = "https://gitlab.redox-os.org/redox-os/redox-initfs.git", features = ["kernel"], default-features = false }
+redox-initfs = { git = "https://gitlab.redox-os.org/redox-os/redox-initfs.git", default-features = false }
 redox-exec = { git = "https://gitlab.redox-os.org/redox-os/relibc.git" }
 redox_syscall = "0.4"
 

src/exec.rs

@@ -7,8 +7,6 @@ use syscall::flag::{O_CLOEXEC, O_RDONLY};
 use redox_exec::*;
 
 pub fn main() -> ! {
-    let initfs_length;
-
     let envs = {
         let mut env = [0_u8; 4096];
 
@@ -23,21 +21,6 @@ pub fn main() -> ! {
 
         let raw_iter = || env.split(|c| *c == b'\n').filter(|var| !var.is_empty());
 
-        let mut initfs_length_opt = None;
-
-        for var in raw_iter() {
-            let equal_sign = var.iter().position(|c| *c == b'=').expect("malformed environment variable");
-            let name = &var[..equal_sign];
-            let value = &var[equal_sign + 1..];
-
-            match name {
-                b"INITFS_LENGTH" => initfs_length_opt = core::str::from_utf8(value).ok().and_then(|s| usize::from_str_radix(s, 16).ok()),
-
-                _ => continue,
-            }
-        }
-        initfs_length = initfs_length_opt.expect("missing INITFS_LENGTH");
-
         let iter = || raw_iter().filter(|var| !var.starts_with(b"INITFS_"));
 
         iter().map(|var| var.to_owned()).collect::<Vec<_>>()
@@ -48,10 +31,12 @@ pub fn main() -> ! {
         static __initfs_header: u8;
     }
 
+    let initfs_length = unsafe { (*(core::ptr::addr_of!(__initfs_header) as *const redox_initfs::types::Header)).initfs_size };
+
     unsafe {
         // Creating a reference to NULL is UB. Mask the UB for now using black_box.
         // FIXME use a raw pointer and inline asm for reading instead for the initfs header.
-        spawn_initfs(core::ptr::addr_of!(__initfs_header), initfs_length);
+        spawn_initfs(core::ptr::addr_of!(__initfs_header), initfs_length.get() as usize);
     }
     const CWD: &[u8] = b"/scheme/initfs";
     let extrainfo = redox_exec::ExtraInfo {