diff --git a/crates/private/support/sel4-simple-task/config-types/Cargo.nix b/crates/private/support/sel4-simple-task/config-types/Cargo.nix
index 4c46f2b5c..0ac5edbaa 100644
--- a/crates/private/support/sel4-simple-task/config-types/Cargo.nix
+++ b/crates/private/support/sel4-simple-task/config-types/Cargo.nix
@@ -12,7 +12,7 @@ mk {
     inherit (versions) cfg-if;
     serde = serdeWith [ "derive" ];
   };
-  target."cfg(target_env = \"sel4\")".dependencies = {
+  target."cfg(target_os = \"none\")".dependencies = {
     inherit (localCrates)
       sel4
       sel4-simple-task-threading
diff --git a/crates/private/support/sel4-simple-task/config-types/Cargo.toml b/crates/private/support/sel4-simple-task/config-types/Cargo.toml
index 854d830a0..df567ea4b 100644
--- a/crates/private/support/sel4-simple-task/config-types/Cargo.toml
+++ b/crates/private/support/sel4-simple-task/config-types/Cargo.toml
@@ -20,6 +20,6 @@ license = "BSD-2-Clause"
 cfg-if = "1.0.0"
 serde = { version = "1.0.147", default-features = false, features = ["derive"] }
 
-[target."cfg(target_env = \"sel4\")".dependencies]
+[target."cfg(target_os = \"none\")".dependencies]
 sel4 = { path = "../../../../sel4" }
 sel4-simple-task-threading = { path = "../threading" }
diff --git a/crates/private/support/sel4-simple-task/config-types/src/lib.rs b/crates/private/support/sel4-simple-task/config-types/src/lib.rs
index c8b422ae4..fc4e1d287 100644
--- a/crates/private/support/sel4-simple-task/config-types/src/lib.rs
+++ b/crates/private/support/sel4-simple-task/config-types/src/lib.rs
@@ -11,7 +11,7 @@ use core::marker::PhantomData;
 use serde::{Deserialize, Serialize};
 
 cfg_if::cfg_if! {
-    if #[cfg(target_env = "sel4")] {
+    if #[cfg(target_os = "none")] {
         mod when_sel4;
         pub use when_sel4::*;
     } else {
diff --git a/crates/sel4-generate-target-specs/src/main.rs b/crates/sel4-generate-target-specs/src/main.rs
index bc870adb4..89dd8162e 100644
--- a/crates/sel4-generate-target-specs/src/main.rs
+++ b/crates/sel4-generate-target-specs/src/main.rs
@@ -105,7 +105,6 @@ impl Config {
         {
             let options = &mut target.options;
             options.is_builtin = false;
-            options.env = "sel4".into();
             options.exe_suffix = ".elf".into();
             options.eh_frame_header = !self.minimal;
         }
diff --git a/support/targets/aarch64-sel4-microkit-minimal.json b/support/targets/aarch64-sel4-microkit-minimal.json
index 80a73e2ef..884759773 100644
--- a/support/targets/aarch64-sel4-microkit-minimal.json
+++ b/support/targets/aarch64-sel4-microkit-minimal.json
@@ -4,7 +4,6 @@
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
   "eh-frame-header": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "link-script": "__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/aarch64-sel4-microkit-resettable-minimal.json b/support/targets/aarch64-sel4-microkit-resettable-minimal.json
index 38fc99f2c..aaacc1f43 100644
--- a/support/targets/aarch64-sel4-microkit-resettable-minimal.json
+++ b/support/targets/aarch64-sel4-microkit-resettable-minimal.json
@@ -4,7 +4,6 @@
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
   "eh-frame-header": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "link-script": "SECTIONS {\n    .persistent : {\n        *(.persistent .persistent.*)\n    }\n} INSERT BEFORE .data;\n\nASSERT(DEFINED(_reset), \"_reset is not defined\")\n\nENTRY(_reset)\n__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/aarch64-sel4-microkit-resettable.json b/support/targets/aarch64-sel4-microkit-resettable.json
index 5aec2a8ce..dcc7570f6 100644
--- a/support/targets/aarch64-sel4-microkit-resettable.json
+++ b/support/targets/aarch64-sel4-microkit-resettable.json
@@ -3,7 +3,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "has-thread-local": true,
diff --git a/support/targets/aarch64-sel4-microkit.json b/support/targets/aarch64-sel4-microkit.json
index 2d02213cf..e9dac07b0 100644
--- a/support/targets/aarch64-sel4-microkit.json
+++ b/support/targets/aarch64-sel4-microkit.json
@@ -3,7 +3,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "has-thread-local": true,
diff --git a/support/targets/aarch64-sel4-minimal.json b/support/targets/aarch64-sel4-minimal.json
index a20c11462..3a7c1c98c 100644
--- a/support/targets/aarch64-sel4-minimal.json
+++ b/support/targets/aarch64-sel4-minimal.json
@@ -4,7 +4,6 @@
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
   "eh-frame-header": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "linker": "rust-lld",
diff --git a/support/targets/aarch64-sel4.json b/support/targets/aarch64-sel4.json
index 333fb6cac..ca6108baa 100644
--- a/support/targets/aarch64-sel4.json
+++ b/support/targets/aarch64-sel4.json
@@ -3,7 +3,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32",
   "disable-redzone": true,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v8a,+strict-align,+neon,+fp-armv8",
   "has-thread-local": true,
diff --git a/support/targets/armv7a-sel4-minimal.json b/support/targets/armv7a-sel4-minimal.json
index d1deba6a7..6817fa5ff 100644
--- a/support/targets/armv7a-sel4-minimal.json
+++ b/support/targets/armv7a-sel4-minimal.json
@@ -7,7 +7,6 @@
   "disable-redzone": true,
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v7,+thumb2,+soft-float,-neon,+strict-align",
   "linker": "rust-lld",
diff --git a/support/targets/armv7a-sel4.json b/support/targets/armv7a-sel4.json
index f2bfdaf38..ea10d3314 100644
--- a/support/targets/armv7a-sel4.json
+++ b/support/targets/armv7a-sel4.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64",
   "disable-redzone": true,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+v7,+thumb2,+soft-float,-neon,+strict-align",
   "has-thread-local": true,
diff --git a/support/targets/riscv32imac-sel4-minimal.json b/support/targets/riscv32imac-sel4-minimal.json
index 67d19abe0..854c2f632 100644
--- a/support/targets/riscv32imac-sel4-minimal.json
+++ b/support/targets/riscv32imac-sel4-minimal.json
@@ -5,7 +5,6 @@
   "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "linker": "rust-lld",
diff --git a/support/targets/riscv32imac-sel4.json b/support/targets/riscv32imac-sel4.json
index 7d8c0aa29..89c559687 100644
--- a/support/targets/riscv32imac-sel4.json
+++ b/support/targets/riscv32imac-sel4.json
@@ -4,7 +4,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv32imafc-sel4-minimal.json b/support/targets/riscv32imafc-sel4-minimal.json
index 62ffee573..e802bc5f4 100644
--- a/support/targets/riscv32imafc-sel4-minimal.json
+++ b/support/targets/riscv32imafc-sel4-minimal.json
@@ -5,7 +5,6 @@
   "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c,+f",
   "linker": "rust-lld",
diff --git a/support/targets/riscv32imafc-sel4.json b/support/targets/riscv32imafc-sel4.json
index 4f24dd24c..d3b476bae 100644
--- a/support/targets/riscv32imafc-sel4.json
+++ b/support/targets/riscv32imafc-sel4.json
@@ -4,7 +4,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c,+f",
   "has-thread-local": true,
diff --git a/support/targets/riscv64gc-sel4-microkit-minimal.json b/support/targets/riscv64gc-sel4-microkit-minimal.json
index d2429ccc8..1f6966f02 100644
--- a/support/targets/riscv64gc-sel4-microkit-minimal.json
+++ b/support/targets/riscv64gc-sel4-microkit-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "link-script": "__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/riscv64gc-sel4-microkit-resettable-minimal.json b/support/targets/riscv64gc-sel4-microkit-resettable-minimal.json
index 081f3a93f..37ec54429 100644
--- a/support/targets/riscv64gc-sel4-microkit-resettable-minimal.json
+++ b/support/targets/riscv64gc-sel4-microkit-resettable-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "link-script": "SECTIONS {\n    .persistent : {\n        *(.persistent .persistent.*)\n    }\n} INSERT BEFORE .data;\n\nASSERT(DEFINED(_reset), \"_reset is not defined\")\n\nENTRY(_reset)\n__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/riscv64gc-sel4-microkit-resettable.json b/support/targets/riscv64gc-sel4-microkit-resettable.json
index e1c1b3b1e..c195be2ac 100644
--- a/support/targets/riscv64gc-sel4-microkit-resettable.json
+++ b/support/targets/riscv64gc-sel4-microkit-resettable.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv64gc-sel4-microkit.json b/support/targets/riscv64gc-sel4-microkit.json
index e00472f25..14ce2b578 100644
--- a/support/targets/riscv64gc-sel4-microkit.json
+++ b/support/targets/riscv64gc-sel4-microkit.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv64gc-sel4-minimal.json b/support/targets/riscv64gc-sel4-minimal.json
index d43985464..e798c2831 100644
--- a/support/targets/riscv64gc-sel4-minimal.json
+++ b/support/targets/riscv64gc-sel4-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "linker": "rust-lld",
diff --git a/support/targets/riscv64gc-sel4.json b/support/targets/riscv64gc-sel4.json
index e25cf2bd6..75c62c903 100644
--- a/support/targets/riscv64gc-sel4.json
+++ b/support/targets/riscv64gc-sel4.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+f,+d,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv64imac-sel4-microkit-minimal.json b/support/targets/riscv64imac-sel4-microkit-minimal.json
index 2af8e7df4..12a11448d 100644
--- a/support/targets/riscv64imac-sel4-microkit-minimal.json
+++ b/support/targets/riscv64imac-sel4-microkit-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "link-script": "__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/riscv64imac-sel4-microkit-resettable-minimal.json b/support/targets/riscv64imac-sel4-microkit-resettable-minimal.json
index 6b023ee56..09494cbc7 100644
--- a/support/targets/riscv64imac-sel4-microkit-resettable-minimal.json
+++ b/support/targets/riscv64imac-sel4-microkit-resettable-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "link-script": "SECTIONS {\n    .persistent : {\n        *(.persistent .persistent.*)\n    }\n} INSERT BEFORE .data;\n\nASSERT(DEFINED(_reset), \"_reset is not defined\")\n\nENTRY(_reset)\n__sel4_ipc_buffer_obj = (__ehdr_start & ~(4096 - 1)) - 4096;",
diff --git a/support/targets/riscv64imac-sel4-microkit-resettable.json b/support/targets/riscv64imac-sel4-microkit-resettable.json
index 5ba6e3e41..ac1acfc8c 100644
--- a/support/targets/riscv64imac-sel4-microkit-resettable.json
+++ b/support/targets/riscv64imac-sel4-microkit-resettable.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv64imac-sel4-microkit.json b/support/targets/riscv64imac-sel4-microkit.json
index 732999150..44f101412 100644
--- a/support/targets/riscv64imac-sel4-microkit.json
+++ b/support/targets/riscv64imac-sel4-microkit.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "has-thread-local": true,
diff --git a/support/targets/riscv64imac-sel4-minimal.json b/support/targets/riscv64imac-sel4-minimal.json
index 91553bac5..5b2f11d62 100644
--- a/support/targets/riscv64imac-sel4-minimal.json
+++ b/support/targets/riscv64imac-sel4-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "eh-frame-header": false,
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "linker": "rust-lld",
diff --git a/support/targets/riscv64imac-sel4.json b/support/targets/riscv64imac-sel4.json
index 3f6de33b7..6f7a5052b 100644
--- a/support/targets/riscv64imac-sel4.json
+++ b/support/targets/riscv64imac-sel4.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
   "emit-debug-gdb-scripts": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "+m,+a,+c",
   "has-thread-local": true,
diff --git a/support/targets/x86_64-sel4-minimal.json b/support/targets/x86_64-sel4-minimal.json
index 112f621ce..ac290d485 100644
--- a/support/targets/x86_64-sel4-minimal.json
+++ b/support/targets/x86_64-sel4-minimal.json
@@ -6,7 +6,6 @@
   "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
   "disable-redzone": true,
   "eh-frame-header": false,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2,+soft-float",
   "linker": "rust-lld",
diff --git a/support/targets/x86_64-sel4.json b/support/targets/x86_64-sel4.json
index 42e11150a..184095727 100644
--- a/support/targets/x86_64-sel4.json
+++ b/support/targets/x86_64-sel4.json
@@ -5,7 +5,6 @@
   "crt-objects-fallback": "false",
   "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
   "disable-redzone": true,
-  "env": "sel4",
   "exe-suffix": ".elf",
   "features": "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2,+soft-float",
   "has-thread-local": true,