# P2-hwd-misc.patch
# Extract hwd (hardware daemon) Cargo.toml and main.rs improvements.
#
# Files: drivers/hwd/Cargo.toml, drivers/hwd/src/main.rs

diff --git a/drivers/hwd/Cargo.toml b/drivers/hwd/Cargo.toml
index 3d37cfb3..40b51a1b 100644
--- a/drivers/hwd/Cargo.toml
+++ b/drivers/hwd/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 
 [dependencies]
 fdt.workspace = true
+libc.workspace = true
 log.workspace = true
 ron.workspace = true
 libredox = { workspace = true, default-features = false, features = ["std", "call"] }
diff --git a/drivers/hwd/src/main.rs b/drivers/hwd/src/main.rs
index 79360e34..a0462f51 100644
--- a/drivers/hwd/src/main.rs
+++ b/drivers/hwd/src/main.rs
@@ -1,3 +1,5 @@
+use std::os::fd::AsRawFd;
+use std::os::unix::process::CommandExt;
 use std::process;
 
 mod backend;
@@ -37,8 +39,34 @@ fn daemon(daemon: daemon::Daemon) -> ! {
 
     //TODO: launch pcid based on backend information?
     // Must launch after acpid but before probe calls /scheme/acpi/symbols
-    #[allow(deprecated, reason = "we can't yet move this to init")]
-    daemon::Daemon::spawn(process::Command::new("pcid"));
+    // Fire-and-forget: daemon::Daemon::spawn blocks until pcid signals readiness,
+    // but pcid only signals after full PCI enumeration. If enumeration hangs on
+    // real hardware (unresponsive device, complex AML), hwd deadlocks initfs.
+    {
+        match std::io::pipe() {
+            Ok((_read_end, write_end)) => {
+                let write_fd: std::os::fd::OwnedFd = write_end.into();
+                let raw_fd = write_fd.as_raw_fd();
+                let mut cmd = std::process::Command::new("pcid");
+                cmd.env("INIT_NOTIFY", raw_fd.to_string());
+                unsafe {
+                    cmd.pre_exec(move || {
+                        if libc::fcntl(raw_fd, libc::F_SETFD, 0) == -1 {
+                            return Err(std::io::Error::last_os_error());
+                        }
+                        Ok(())
+                    });
+                }
+                match cmd.spawn() {
+                    Ok(_) => {}
+                    Err(err) => log::error!("hwd: failed to spawn pcid: {}", err),
+                }
+            }
+            Err(err) => {
+                log::error!("hwd: failed to create pcid notification pipe: {}", err);
+            }
+        }
+    }
 
     daemon.ready();