Restructure and include basic Rust

.gitignore

@@ -1,6 +1,7 @@
 *~
 _*
 *.o
+*.a
 *.d
 *.asm
 *.sym

Makefile

@@ -1,5 +1,6 @@
 K=kernel
 U=user
+P=programs
 
 OBJS = \
   $K/entry.o \
@@ -11,6 +12,7 @@ OBJS = \
   $K/spinlock.o \
   $K/string.o \
   $K/main.o \
+  $K/rust.a \
   $K/vm.o \
   $K/proc.o \
   $K/swtch.o \
@@ -63,6 +65,10 @@ CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax
 CFLAGS += -I.
 CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
 
+RUSTC = rustc
+TARGET_TRIPLE = riscv64gc-unknown-none-elf
+RUSTFLAGS = -C soft-float=n --target $(TARGET_TRIPLE)
+
 # Disable PIE when possible (for Ubuntu 16.10 toolchain)
 ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]no-pie'),)
 CFLAGS += -fno-pie -no-pie
@@ -89,6 +95,12 @@ tags: $(OBJS) _init
 
 ULIB = $U/ulib.o $U/usys.o $U/printf.o $U/umalloc.o
 
+%.a: %.rs
+	$(RUSTC) $(RUSTFLAGS) --crate-type staticlib -o $@ -L $K $^
+
+%.o: %.c *.h
+	$(CC) $(CFLAGS) -c $^
+
 _%: %.o $(ULIB)
 	$(LD) $(LDFLAGS) -T $U/user.ld -o $@ $^
 	$(OBJDUMP) -S $@ > $*.asm
@@ -116,22 +128,22 @@ mkfs/mkfs: mkfs/mkfs.c $K/fs.h $K/param.h
 .PRECIOUS: %.o
 
 UPROGS=\
-	$U/_cat\
-	$U/_echo\
-	$U/_forktest\
-	$U/_grep\
-	$U/_init\
-	$U/_kill\
-	$U/_ln\
-	$U/_ls\
-	$U/_mkdir\
-	$U/_rm\
-	$U/_sh\
-	$U/_stressfs\
-	$U/_usertests\
-	$U/_grind\
-	$U/_wc\
-	$U/_zombie\
+	$P/_cat\
+	$P/_echo\
+	$P/_forktest\
+	$P/_grep\
+	$P/_grind\
+	$P/_init\
+	$P/_kill\
+	$P/_ln\
+	$P/_ls\
+	$P/_mkdir\
+	$P/_rm\
+	$P/_sh\
+	$P/_stressfs\
+	$P/_usertests\
+	$P/_wc\
+	$P/_zombie\
 
 fs.img: mkfs/mkfs README $(UPROGS)
 	mkfs/mkfs fs.img README $(UPROGS)
@@ -140,7 +152,7 @@ fs.img: mkfs/mkfs README $(UPROGS)
 
 clean: 
 	rm -f *.tex *.dvi *.idx *.aux *.log *.ind *.ilg \
-	*/*.o */*.d */*.asm */*.sym \
+	*/*.o */*.a */*.d */*.asm */*.sym \
 	$U/initcode $U/initcode.out $K/kernel fs.img \
 	mkfs/mkfs .gdbinit \
         $U/usys.S \

kernel/main.c

@@ -6,6 +6,8 @@
 
 volatile static int started = 0;
 
+void rust_main();
+
 // start() jumps here in supervisor mode on all CPUs.
 void
 main()
@@ -16,6 +18,7 @@ main()
     printf("\n");
     printf("xv6 kernel is booting\n");
     printf("\n");
+    rust_main();
     kinit();         // physical page allocator
     kvminit();       // create kernel page table
     kvminithart();   // turn on paging

kernel/printf.c

@@ -59,6 +59,10 @@ printptr(uint64 x)
     consputc(digits[x >> (sizeof(uint64) * 8 - 4)]);
 }
 
+void print(char *raw) {
+  printf("%s", raw);
+}
+
 // Print to the console. only understands %d, %x, %p, %s.
 void
 printf(char *fmt, ...)

kernel/rust.rs

@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+
+use core::ffi::{c_char, CStr};
+
+extern "C" {
+    fn print(message: *const c_char);
+    fn panic(panic_message: *const c_char) -> !;
+}
+
+#[no_mangle]
+pub extern "C" fn rust_main() {
+    unsafe {
+        print(
+            CStr::from_bytes_with_nul(b"Hello from Rust!\0")
+                .unwrap()
+                .as_ptr(),
+        );
+    }
+}
+
+
+#[panic_handler]
+unsafe fn panic_wrapper(_panic_info: &core::panic::PanicInfo) -> ! {
+    panic(CStr::from_bytes_with_nul(b"panic from rust\0").unwrap_or_default().as_ptr())
+}

mkfs/mkfs.c

@@ -132,6 +132,8 @@ main(int argc, char *argv[])
     char *shortname;
     if(strncmp(argv[i], "user/", 5) == 0)
       shortname = argv[i] + 5;
+    else if(strncmp(argv[i], "programs/", 9) == 0)
+      shortname = argv[i] + 9;
     else
       shortname = argv[i];