Add sel4-config build helper for syncing crates to an seL4 kernel build.

sel4-config is a build helper for keeping a crate's features in sync
with an seL4 kernel. sel4_config::get_sel4_features parses a gen_config.h
artifact from an seL4 build and returns the intersection of the feature
set with the features listed in the caller's Cargo.toml.

Change sel4-sys to use sel4-config to collect features (instead of
depending only on features from Cargo.toml). sel4-sys finds the directory
with kernel artifacts using an SEL4_OUT_DIR environment variable. If
that's not set it falls back to ${ROOTDIR}/out/kata/kernel.

Change workspace crates to use resolver="2" to deal with cargo's
mishandling of dependent features (target build of serde polluted by
std build-dep indirect through cargo_toml).

While here make sel4-sys fall back to ${ROOTDIR}/kata/kernel when SEL4_DIR
is not set in the environment.

Change-Id: I47cf2eab4aa8cd2e502f741738f587c222e94716
GitOrigin-RevId: b661f0b78c0bfe70861965a420d25add8a128cb7

apps/system/components/.cargo/config.toml

@@ -1,4 +0,0 @@
-[env]
-# Pathname to seL4 kernel for xml files and (eventually) tools scripts,
-# defaults to "sel4" if not set
-SEL4_DIR = { value = "../../../../../kernel", relative = true }

apps/system/components/DebugConsole/Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "kata-uart-client",
     "zmodem",
 ]
+resolver = "2"
 
 [profile.dev]
 opt-level = 0

apps/system/components/MlCoordinator/Cargo.toml

@@ -5,6 +5,7 @@ members = [
     "kata-ml-interface",
     "kata-vec-core"
 ]
+resolver = "2"
 
 [profile.dev]
 opt-level = 0

apps/system/components/ProcessManager/Cargo.toml

@@ -5,6 +5,8 @@ members = [
     "kata-proc-interface",
     "kata-proc-manager",
 ]
+resolver = "2"
+
 
 [profile.dev]
 opt-level = 0

apps/system/components/SecurityCoordinator/Cargo.toml

@@ -5,6 +5,7 @@ members = [
     "kata-security-coordinator",
     "kata-security-interface",
 ]
+resolver = "2"
 
 [profile.dev]
 opt-level = 0

apps/system/components/StorageManager/Cargo.toml

@@ -5,6 +5,7 @@ members = [
     "kata-storage-interface",
     "kata-storage-manager",
 ]
+resolver = "2"
 
 [profile.dev]
 opt-level = 0

apps/system/components/kata-os-common/Cargo.toml

@@ -3,33 +3,5 @@ name = "kata-os-common"
 version = "0.1.0"
 edition = "2018"
 
-[features]
-default = [
-    "CONFIG_PRINTING",
-    "CONFIG_DEBUG_BUILD",
-    "CONFIG_KERNEL_MCS",
-]
-CONFIG_ARM_HYPERVISOR_SUPPORT = [
-    "sel4-sys/CONFIG_ARM_HYPERVISOR_SUPPORT",
-]
-CONFIG_ARM_SMMU = [
-    "sel4-sys/CONFIG_ARM_SMMU",
-]
-CONFIG_DEBUG_BUILD = [
-    "sel4-sys/CONFIG_DEBUG_BUILD",
-]
-CONFIG_KERNEL_MCS = [
-    "sel4-sys/CONFIG_KERNEL_MCS",
-]
-CONFIG_PRINTING = [
-    "sel4-sys/CONFIG_PRINTING",
-]
-CONFIG_SMP_SUPPORT = [
-    "sel4-sys/CONFIG_SMP_SUPPORT",
-]
-CONFIG_VTX = [
-    "sel4-sys/CONFIG_VTX",
-]
-
 [dependencies]
 sel4-sys = { path = "src/sel4-sys" }

apps/system/components/kata-os-common/src/sel4-config/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "sel4-config"
+version = "0.1.0"
+edition = "2018"
+description = "build glue for seL4 kernel configuration"
+
+[lib]
+path = "src/lib.rs"
+
+[dependencies]
+cargo_toml = "0.10.2"

apps/system/components/kata-os-common/src/sel4-config/src/lib.rs

@@ -0,0 +1,46 @@
+// Cargo/rust build glue to import seL4 kernel configuration. We
+// parse the gen_config.h file from a build area to find features
+// needed by a dependent crate (sel4-sys, kata-os-rootserver, etc).
+//
+// The caller is responsible for supplying a pathname to the top
+// of the kernel build area. Typically this comes from the
+// SEL4_OUT_DIR environment variable.
+
+use std::collections::BTreeSet;
+use std::env;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+use std::string::String;
+use std::vec::Vec;
+
+pub fn get_sel4_features(sel4_out_dir: &str) -> Vec<String> {
+    // Parse the kernel's gen_config.h file to get features.
+    let gen_config_file =
+        File::open(format!("{}/gen_config/kernel/gen_config.h", sel4_out_dir)).unwrap();
+    let kernel_config_features = BufReader::new(gen_config_file)
+        .lines()
+        .filter_map(|line| {
+            let line = line.unwrap();
+            let mut splitted = line.split_whitespace();
+            match (splitted.next()?, splitted.next()?) {
+                ("#define", param) => Some(param.to_owned()),
+                _ => None,
+            }
+        })
+        .collect::<BTreeSet<_>>();
+    println!("kernel_config_features {:?}", kernel_config_features);
+
+    // Return only features specified in the Cargo.toml.
+    let manifest_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()).join("Cargo.toml");
+    let manifest = cargo_toml::Manifest::from_path(manifest_path).unwrap();
+    manifest
+        .features
+        .into_keys()
+        .collect::<BTreeSet<String>>()
+        .intersection(&kernel_config_features)
+        .cloned()
+        .collect::<Vec<String>>()
+}
+
+// TODO(sleffler): unit tests

apps/system/components/kata-os-common/src/sel4-sys/Cargo.toml

@@ -17,23 +17,28 @@ readme = "README.md"
 license = "MIT/Apache-2.0"
 build = "build.rs"
 
+# NB: the sel4-config crate tries to sync features to a kernel build by
+#   parsing build artifacts (see the crate).
+[build-dependencies]
+sel4-config = { path = "../sel4-config" }
+
 # NB: used by build.rs
-[env]
+[build-env]
 # Name of python3 interpreter executable, defaults to "python3"
 PYTHON = "python3"
 
+# Pathname to seL4 kernel source
+SEL4_DIR = "${ROOTDIR}kata/kernel"
+
+# Pathname to seL4 kernel build artifacts (used by sel4-config)
+SEL4_OUT_DIR = "${ROOTDIR}out/kata/kernel"
+
 # Beware CONFIG_KERNEL_MCS & CONFIG_SMP_SUPPORT must match the kernel
 # config for syscall numbering (aka invocation labeling) to line up.
 # Other syscalls api's are generated only when the associated config
 # knobs are set but do not affect the syscall ABI (e.g. CONFIG_PRINTING).
 [features]
-default = [
-#    "CONFIG_KERNEL_MCS",
-    "CONFIG_PRINTING",
-    "CONFIG_DEBUG_BUILD",
-    "CONFIG_SET_TLS_BASE_SELF",
-]
-# Changes api, blech
+default = []
 CONFIG_KERNEL_MCS = []
 CONFIG_PRINTING = []
 CONFIG_DEBUG_BUILD = []
@@ -44,12 +49,9 @@ CONFIG_BENCHMARK_TRACK_UTILISATION = []
 # TCBSetBreakpoint, TCBUnsetBreakpoint, TCBSetTLSBase
 CONFIG_HARDWARE_DEBUG_API = []
 CONFIG_SET_TLS_BASE_SELF = []
-# note: if you're looking at these, be aware that hypervisor support is not
-# yet available at all. these features shouldn't be enabled.
 CONFIG_VTX = []
 CONFIG_ARM_SMMU = []
 CONFIG_ARM_HYPERVISOR_SUPPORT = []
-unstable = [] # XXX?
 
 [lib]
 path = "lib.rs"

apps/system/components/kata-os-common/src/sel4-sys/build.rs

@@ -27,7 +27,29 @@ fn main() {
 
     // Default to "seL4" for backwards compat; can either use git submodule or
     // symbolic link (neither recommended)
-    let sel4_dir = env::var("SEL4_DIR").unwrap_or_else(|_| "seL4".to_string());
+    let sel4_dir = env::var("SEL4_DIR").unwrap_or_else(
+        |_| format!("{}/kata/kernel", env::var("ROOTDIR").unwrap())
+    );
+    println!("sel4_dir {}", sel4_dir);
+
+    // If SEL4_OUT_DIR is not set we expect the kernel build at a fixed
+    // location relative to the ROOTDIR env variable.
+    println!("SEL4_OUT_DIR {:?}", env::var("SEL4_OUT_DIR"));
+    let sel4_out_dir = env::var("SEL4_OUT_DIR").unwrap_or_else(
+        |_| format!("{}/out/kata/kernel", env::var("ROOTDIR").unwrap())
+    );
+    println!("sel4_out_dir {}", sel4_out_dir);
+
+    // Dredge seL4 kerenl config for settings we need as features to generate
+    // correct code: e.g. CONFIG_KERNEL_MCS enables MCS support which changes
+    // the system call numbering.
+    let features = sel4_config::get_sel4_features(&sel4_out_dir);
+    println!("features = {:?}", features);
+    let mut has_mcs = false;
+    for feature in features {
+        println!("cargo:rustc-cfg=feature=\"{}\"", feature);
+        if feature.as_str() == "CONFIG_KERNEL_MCS" { has_mcs = true; }
+    }
 
     // Use CARGO_TARGET_ARCH and CARGO_TARGET_POINTER_WIDTH
     // to select the target architecture;
@@ -59,25 +81,25 @@ fn main() {
         "{}/libsel4/sel4_arch_include/{}/interfaces/sel4arch.xml",
         sel4_dir, arch
     );
-    let args = vec![
-        "tools/syscall_stub_gen.py",
+
+    let mut cmd = Command::new("/usr/bin/env");
+    cmd.arg(&python_bin)
+       .arg("tools/syscall_stub_gen.py");
+    if has_mcs {
+        cmd.arg("--mcs");
+    }
+    cmd.args(&[
         "-a",
         arch,
         "-w",
         cargo_target_pointer_width.as_str(),
         "--buffer",
-        #[cfg(feature = "CONFIG_KERNEL_MCS")]
-        "--mcs",
         "-o",
         &*outfile,
         &*xml_interfaces_file,
         &*xml_arch_file,
         &*xml_sel4_arch_file,
-    ];
-
-    let mut cmd = Command::new("/usr/bin/env");
-    cmd.arg(&python_bin).args(&args);
-
+    ]);
     println!("Running: {:?}", cmd);
     assert!(cmd.status().unwrap().success());
 
@@ -91,27 +113,30 @@ fn main() {
         sel4_dir, arch
     );
     let mut cmd = Command::new("/usr/bin/env");
-    cmd.arg(&python_bin).args(&[
-        "tools/invocation_header_gen.py",
-        "--dest",
-        &*format!("{}/{}_invocation.rs", out_dir, arch),
-        &*xml_interfaces_file,
-        &*xml_arch_file,
-        &*xml_sel4_arch_file,
-    ]);
+    cmd.arg(&python_bin)
+       .args(&[
+           "tools/invocation_header_gen.py",
+           "--dest",
+           &*format!("{}/{}_invocation.rs", out_dir, arch),
+           &*xml_interfaces_file,
+           &*xml_arch_file,
+           &*xml_sel4_arch_file,
+       ]);
     println!("Running {:?}", cmd);
     assert!(cmd.status().unwrap().success());
 
     // TODO(sleffler): requires pip install tempita
     let mut cmd = Command::new("/usr/bin/env");
-    cmd.arg(&python_bin).args(&[
-        "tools/syscall_header_gen.py",
-        #[cfg(feature = "CONFIG_KERNEL_MCS")]
-        "--mcs",
-        "--xml",
-        &*format!("{}/libsel4/include/api/syscall.xml", sel4_dir),
-        "--dest",
-        &*format!("{}/syscalls.rs", out_dir),
+    cmd.arg(&python_bin)
+       .arg("tools/syscall_header_gen.py");
+    if has_mcs {
+        cmd.arg("--mcs");
+    }
+    cmd.args(&[
+       "--xml",
+       &*format!("{}/libsel4/include/api/syscall.xml", sel4_dir),
+       "--dest",
+       &*format!("{}/syscalls.rs", out_dir),
     ]);
     println!("Running {:?}", cmd);
     assert!(cmd.status().unwrap().success());
@@ -128,12 +153,14 @@ fn main() {
     ))
     .unwrap();
     let mut cmd = Command::new("/usr/bin/env");
-    cmd.arg(&python_bin)
-        .arg("tools/bitfield_gen.py")
-        .arg("--language=rust")
-        //       .arg("--word-size=32")
-        .stdin(unsafe { Stdio::from_raw_fd(bfin.as_raw_fd()) })
-        .stdout(unsafe { Stdio::from_raw_fd(bfout.as_raw_fd()) });
+    cmd.args(&[
+           &python_bin,
+          "tools/bitfield_gen.py",
+          "--language=rust",
+  //      "--word-size=32"
+       ])
+       .stdin(unsafe { Stdio::from_raw_fd(bfin.as_raw_fd()) })
+       .stdout(unsafe { Stdio::from_raw_fd(bfout.as_raw_fd()) });
     println!("Running {:?}", cmd);
     assert!(cmd.status().unwrap().success());
     std::mem::forget(bfin);