Makefile

@@ -8,6 +8,7 @@ OBJS = \
   $K/kalloc.o \
   $K/spinlock.o \
   $K/string.o \
+  $K/main.o \
   $K/vm.o \
   $K/proc.o \
   $K/swtch.o \

kernel/main.c

@@ -0,0 +1,43 @@
+#include "types.h"
+#include "param.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "defs.h"
+
+volatile static int started = 0;
+
+// start() jumps here in supervisor mode on all CPUs.
+void main() {
+	if (cpuid() == 0) {
+		consoleinit();
+		printfinit();
+		printf("\n");
+		printf("xv6 kernel is booting\n");
+		printf("\n");
+		kinit();			// physical page allocator
+		kvminit();			// create kernel page table
+		kvminithart();		// turn on paging
+		procinit();			// process table
+		trapinit();			// trap vectors
+		trapinithart();		// install kernel trap vector
+		plicinit();			// set up interrupt controller
+		plicinithart();		// ask PLIC for device interrupts
+		binit();			// buffer cache
+		iinit();			// inode table
+		fileinit();			// file table
+		virtio_disk_init(); // emulated hard disk
+		userinit();			// first user process
+		__sync_synchronize();
+		started = 1;
+	} else {
+		while (started == 0)
+			;
+		__sync_synchronize();
+		printf("hart %d starting\n", cpuid());
+		kvminithart();	// turn on paging
+		trapinithart(); // install kernel trap vector
+		plicinithart(); // ask PLIC for device interrupts
+	}
+
+	scheduler();
+}

kernel/spinlock.c

@@ -8,6 +8,12 @@
 #include "proc.h"
 #include "defs.h"
 
+void initlock(struct spinlock *lk, char *name) {
+	lk->name = name;
+	lk->locked = 0;
+	lk->cpu = 0;
+}
+
 // Acquire the lock.
 // Loops (spins) until the lock is acquired.
 void acquire(struct spinlock *lk) {

theseus/src/kmain.rs

@@ -1,58 +0,0 @@
-use crate::riscv;
-
-extern "C" {
-	fn cpuid() -> u64;
-	fn consoleinit();
-	fn printfinit();
-	fn printf(msg: *const i8);
-	fn kinit();
-	fn kvminit();
-	fn kvminithart();
-	fn procinit();
-	fn trapinit();
-	fn trapinithart();
-	fn plicinit();
-	fn plicinithart();
-	fn binit();
-	fn iinit();
-	fn fileinit();
-	fn virtio_disk_init();
-	fn userinit();
-	fn scheduler();
-}
-
-pub static mut started: bool = false;
-
-pub unsafe fn kmain() {
-	if cpuid() == 0 {
-		consoleinit();
-		printfinit();
-		printf(c"\n".as_ptr());
-		printf(c"xv6 kernel is booting\n".as_ptr());
-		printf(c"\n".as_ptr());
-		kinit(); // physical page allocator
-		kvminit(); // create kernel page table
-		kvminithart(); // turn on paging
-		procinit(); // process table
-		trapinit(); // trap vectors
-		trapinithart(); // install kernel trap vector
-		plicinit(); // set up interrupt controller
-		plicinithart(); // ask PLIC for device interrupts
-		binit(); // buffer cache
-		iinit(); // inode table
-		fileinit(); // file table
-		virtio_disk_init(); // emulated hard disk
-		userinit(); // first user process
-		riscv::barrier();
-		started = true;
-	} else {
-		while !started {}
-		riscv::barrier();
-		// printf("hart %d starting\n", cpuid());
-		kvminithart(); // turn on paging
-		trapinithart(); // install kernel trap vector
-		plicinithart(); // ask PLIC for device interrupts
-	}
-
-	scheduler();
-}

theseus/src/lib.rs

@@ -1,9 +1,6 @@
 #![no_std]
 #![crate_type = "staticlib"]
 
-use core::ffi::CStr;
-
-pub mod kmain;
 pub mod memlayout;
 pub mod param;
 pub mod riscv;
@@ -13,16 +10,17 @@ pub mod uart;
 
 extern "C" {
 	// printf.c
-	fn panic(s: *const i8);
+	fn panic(s: *const u8);
 }
 
-static PANIC_MSG: &CStr = c"!RUST PANIC!";
+/// '!RUST PANIC!\0'
+static PANIC_MSG: [u8; 13] = [33, 82, 85, 83, 84, 32, 80, 65, 78, 73, 67, 33, 0];
 
 #[panic_handler]
 #[no_mangle]
 fn panic_handler(_info: &core::panic::PanicInfo) -> ! {
 	unsafe {
-		panic(PANIC_MSG.as_ptr());
+		panic(core::ptr::addr_of!(PANIC_MSG[0]));
 	}
 	loop {}
 }

theseus/src/riscv.rs

@@ -327,9 +327,3 @@ pub fn PX(level: u64, va: u64) -> u64 {
 // Sv39, to avoid having to sign-extend virtual addresses
 // that have the high bit set.
 pub const MAXVA: u64 = 1 << (9 + 9 + 9 + 12 - 1);
-
-/// Hardware memory barrier
-#[inline]
-pub unsafe fn barrier() {
-	asm!("fence")
-}

theseus/src/spinlock.rs

@@ -1,18 +1,9 @@
-use core::ptr::null_mut;
-
 // Mutual exclusion lock.
 #[repr(C)]
 pub struct SpinLock {
 	// Is the lock held?
 	pub locked: u32, // C boolean
 	// For debugging:
-	pub name: *const i8, // Name of lock.
+	pub name: Option<*mut ()>, // Name of lock.
-	pub cpu: *mut (),    // The cpu holding the lock.
+	pub cpu: Option<*mut ()>,  // The cpu holding the lock.
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn initlock(lock: *mut SpinLock, name: *const i8) {
-	(*lock).name = name;
-	(*lock).locked = 0;
-	(*lock).cpu = null_mut();
 }

theseus/src/start.rs

@@ -1,7 +1,6 @@
 use core::arch::asm;
 use core::usize;
 
-use crate::kmain::kmain;
 use crate::memlayout::{CLINT_MTIME, CLINT_MTIMECMP};
 use crate::param::NCPU;
 use crate::riscv as rv;
@@ -9,6 +8,9 @@ use crate::riscv as rv;
 extern "C" {
 	// assembly code in kernelvec.S for machine-mode timer interrupt.
 	fn timervec();
+
+	// main.c
+	fn main();
 }
 
 #[repr(align(16))]
@@ -32,7 +34,7 @@ pub unsafe extern "C" fn start() {
 
 	// set M Exception Program Counter to main, for mret.
 	// requires gcc -mcmodel=medany
-	rv::w_mepc(kmain as *const () as u64);
+	rv::w_mepc(main as *const () as u64);
 
 	// disable paging for now.
 	rv::w_satp(0);

theseus/src/uart.rs

@@ -1,16 +1,11 @@
-use crate::{
+use crate::{memlayout::UART0, spinlock::SpinLock};
-	memlayout::UART0,
+use core::ptr::addr_of_mut;
-	spinlock::{initlock, SpinLock},
-};
-use core::{
-	ffi::CStr,
-	ptr::{addr_of_mut, null, null_mut},
-};
 
 extern "C" {
 	// spinlock.c
 	fn push_off();
 	fn pop_off();
+	fn initlock(spinlock: *mut SpinLock, name: *const u8);
 	fn acquire(spinlock: *mut SpinLock);
 	fn release(spinlock: *mut SpinLock);
 
@@ -65,11 +60,12 @@ pub fn WriteReg(reg: u8, v: u8) {
 // the transmit output buffer.
 static mut uart_tx_lock: crate::spinlock::SpinLock = crate::spinlock::SpinLock {
 	locked: 0,
-	cpu: null_mut(),
+	cpu: None,
-	name: null(),
+	name: None,
 };
 
-static UART_LOCK_NAME: &CStr = c"uart";
+// NOTE: string 'uart\0' for c-implmentation of spinlock. Stupid but works.
+static UART_LOCK_NAME: [u8; 5] = [117, 97, 114, 116, 0];
 
 const UART_TX_BUF_SIZE: usize = 32;
 static mut uart_tx_buf: [u8; UART_TX_BUF_SIZE] = [0; UART_TX_BUF_SIZE];