rv64: static libc for riscv64

kernel/src/arch/riscv64/exception.rs

@@ -3,6 +3,7 @@ use core::arch::global_asm;
 use abi::{arch::SavedFrame, primitive_enum, process::Signal, SyscallFunction};
 use kernel_arch::task::TaskFrame;
 use libk::{device::external_interrupt_controller, task::thread::Thread};
+use libk_mm::PageFaultKind;
 use tock_registers::interfaces::ReadWriteable;
 
 use kernel_arch_riscv64::{mem, registers::STVEC};
@@ -59,20 +60,39 @@ pub fn init_smode_exceptions() {
     // STVEC.modify(STVEC::MODE::Vectored);
 }
 
+impl Cause {
+    fn is_page_fault(&self) -> bool {
+        matches!(
+            self,
+            Self::LoadPageFault
+                | Self::StorePageFault
+                | Self::LoadAccessFault
+                | Self::StoreAccessFault
+                | Self::InstructionPageFault
+                | Self::InstructionAccessFault
+        )
+    }
+}
+
 unsafe fn umode_exception_handler(frame: &mut TrapFrame) {
     let thread = Thread::current();
 
     let cause = Cause::try_from(frame.scause).ok();
 
     let (dump, dump_tval) = match cause {
-        Some(Cause::LoadPageFault)
-        | Some(Cause::StorePageFault)
-        | Some(Cause::LoadAccessFault)
-        | Some(Cause::StoreAccessFault)
-        | Some(Cause::InstructionPageFault)
-        | Some(Cause::InstructionAccessFault) => {
-            thread.raise_signal(Signal::MemoryAccessViolation);
-            (true, true)
+        Some(cause) if cause.is_page_fault() => {
+            let kind = match cause {
+                Cause::LoadPageFault => PageFaultKind::TranslationFault { write: false },
+                Cause::StorePageFault => PageFaultKind::TranslationFault { write: true },
+                Cause::StoreAccessFault => PageFaultKind::WriteFault,
+                _ => PageFaultKind::Other,
+            };
+            if thread.handle_page_fault(frame.stval, kind).is_ok() {
+                (false, false)
+            } else {
+                thread.raise_signal(Signal::MemoryAccessViolation);
+                (true, true)
+            }
         }
         Some(Cause::EcallUmode) => {
             let func = frame.an[0];

userspace/lib/ygglibc/build.rs

@@ -86,10 +86,17 @@ fn compile_crt0(arch: &str, output_dir: impl AsRef<Path>) {
         .arg("-fPIC")
         .arg("-c");
 
-    if arch == "i686" {
-        command.arg("-m32");
+    match arch {
+        "i686" => {
+            command.arg("-m32");
+        }
+        "riscv64" => {
+            command.arg("-march=rv64gc");
+        }
+        _ => (),
     }
 
+
     command
         .arg("-o")
         .arg(output_dir.join("crt0.o"))

userspace/lib/ygglibc/crt/riscv64/crt0.c

@@ -0,0 +1,6 @@
+extern void __ygglibc_entry(const void *, const void *);
+extern int main(int, const char **, const char **);
+
+void _start(const void *arg) {
+    __ygglibc_entry(main, arg);
+}

userspace/lib/ygglibc/etc/riscv64-unknown-none.json

@@ -0,0 +1,33 @@
+{
+  "arch": "riscv64",
+  "os": "none",
+  "cpu": "generic-rv64",
+  "llvm-target": "riscv64",
+  "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
+  "max-atomic-width": 64,
+  "target-pointer-width": "64",
+  "features": "+m,+a,+f,+d,+c",
+
+  "disable-redzone": true,
+  "executables": true,
+  "panic-strategy": "abort",
+  "dynamic-linking": true,
+  "relocation-model": "pic",
+  "position-independent-executables": true,
+  "crt-static-allows-dylibs": true,
+  "crt-static-respected": true,
+
+  "has-thread-local": true,
+
+  "crt-objects-fallback": "false",
+  "emit-debug-gdb-scripts": false,
+  "llvm-abiname": "lp64d",
+
+  "linker": "rust-lld",
+  "linker-flavor": "ld.lld",
+  "pre-link-args": {
+    "ld.lld": [
+      "--dynamic-linker=/libexec/dyn-loader"
+    ]
+  }
+}

userspace/lib/ygglibc/src/headers/setjmp/mod.rs

@@ -13,4 +13,9 @@ pub mod aarch64;
 #[cfg(any(target_arch = "aarch64", rust_analyzer))]
 pub use aarch64::__jmp_buf;
 
+#[cfg(any(target_arch = "riscv64", rust_analyzer))]
+pub mod riscv64;
+#[cfg(any(target_arch = "riscv64", rust_analyzer))]
+pub use riscv64::__jmp_buf;
+
 pub type jmp_buf = __jmp_buf;

userspace/lib/ygglibc/src/headers/setjmp/riscv64.rs

@@ -0,0 +1,37 @@
+use core::ffi::c_int;
+
+pub type __jmp_buf = [usize; 8];
+
+// TODO
+
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn setjmp(buf: *mut __jmp_buf) -> c_int {
+    core::arch::naked_asm!(
+        r#"
+        j .
+    "#
+    );
+}
+
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn _setjmp(buf: *mut __jmp_buf) -> c_int {
+    core::arch::naked_asm!("j .");
+}
+
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn longjmp(buf: *mut __jmp_buf, val: c_int) -> c_int {
+    core::arch::naked_asm!(
+        r#"
+        j .
+    "#
+    )
+}
+
+#[no_mangle]
+#[naked]
+unsafe extern "C" fn _longjmp(buf: *mut __jmp_buf, val: c_int) -> c_int {
+    core::arch::naked_asm!("j .")
+}

xtask/src/build/toolchain_c.rs

@@ -216,7 +216,7 @@ pub fn install_llvm_compiler(env: &BuildEnv) -> Result<Llvm, Error> {
         }
 
         command
-            .arg("-DLLVM_TARGETS_TO_BUILD=X86;AArch64")
+            .arg("-DLLVM_TARGETS_TO_BUILD=X86;AArch64;RISCV")
             .arg(&format!("-DCMAKE_INSTALL_PREFIX={}", root.display()))
             .arg("-GNinja")
             .arg("../llvm");