Various minor fixes.

Removed some commented out code.
Removed excessive printfs.
Fixed spid not initialising for mm0
Fixed some faults with fs0.

TODO:
- Need to store vfs files in a separate list.
- Need to define vnum as a vfs-file-specific data, i.e. in priv_data field of vm_file.
- Need to then fix vfs_receive_sys_open.

.gdbinit

@@ -6,4 +6,3 @@ break break_virtual
 continue
 stepi
 sym start.axf
-

README

@@ -133,8 +133,8 @@ Codezero is an operating system that targets embedded systems. It supports the
 most fundamental posix calls and modern features such as demand-paging and has a
 virtual filesystem layer. Different from other posix-like systems, it is based
 on a microkernel design. It has a cleanly separated set of services, it is small
-and well-focused. Its design is carefully thought out, so it's not just a
-mock-up implementation of an operating system API. Its source code is also
+and well-focused. It's design is carefully thought out, so it's not just a
+mock-up implementation of an operating system API. It's source code is also
 freely available. For these reasons it is a good candidate as systems software
 to be used on embedded platforms. Currently it has little or no users, therefore
 compared to systems with a saturated user base it is possible to tailor it

src/api/kip.c

@@ -23,19 +23,19 @@ int __sys_kread(int rd, void *dest)
 
 	switch(rd) {
 	case KDATA_PAGE_MAP:
-		printk("Handling KDATA_PAGE_MAP request.\n");
+		// printk("Handling KDATA_PAGE_MAP request.\n");
 		if (check_access(vaddr, sizeof(page_map), MAP_USR_RW_FLAGS) < 0)
 			return -EINVAL;
 		memcpy(dest, &page_map, sizeof(page_map));
 		break;
 	case KDATA_BOOTDESC:
-		printk("Handling KDATA_BOOTDESC request.\n");
+		// printk("Handling KDATA_BOOTDESC request.\n");
 		if (check_access(vaddr, bootdesc->desc_size, MAP_USR_RW_FLAGS) < 0)
 			return -EINVAL;
 		memcpy(dest, bootdesc, bootdesc->desc_size);
 		break;
 	case KDATA_BOOTDESC_SIZE:
-		printk("Handling KDATA_BOOTDESC_SIZE request.\n");
+		// printk("Handling KDATA_BOOTDESC_SIZE request.\n");
 		if (check_access(vaddr, sizeof(unsigned int), MAP_USR_RW_FLAGS) < 0)
 			return -EINVAL;
 		*(unsigned int *)dest = bootdesc->desc_size;

src/api/syscall.c

@@ -49,75 +49,6 @@ int sys_schedule(struct syscall_args *regs)
 	return 0;
 }
 
-#if 0
-/*
- * THIS CODE IS TO BE USED WHEN MODIFYING PAGE TABLES FOR SHARED MEMORY!!!
- */
-int do_shm_setup(struct shm_kdata *kdata)
-{
-	struct ktcb *sender, *receiver;
-	unsigned long sndphys, sndvirt, rcvvirt;
-
-	if (!(sender = find_task(kdata->sender)))
-		return -1;
-	if (!(receiver = find_task(kdata->receiver)))
-		return -1;
-
-	/*
-	 * There's no guarantee that shared pages are contiguous in physical,
-	 * therefore every virtual page in the sharer shall be converted for
-	 * its physical address, and each of those addresses are mapped.
-	 */
-	for (int i = 0; i < kdata->npages; i++) {
-		/* The sender virtual address for each shared page */
-		sndvirt = __pfn_to_addr(kdata->send_pfn) + (i * PAGE_SIZE);
-
-		/* The corresponding receiver virtual address */
-		rcvvirt = __pfn_to_addr(kdata->recv_pfn) + (i * PAGE_SIZE);
-
-		/* Converted to physical, through the sharer's page table. */
-		sndphys = __pte_to_addr(virt_to_pte_from_pgd(sndvirt,
-							     sender->pgd));
-		/*
-		 * Mapped to virtual in the sharee's address space. Note this
-		 * is mapped as uncached, in order to avoid cache aliasing
-		 * issues in ARM v5, which is VIVT. A possible optimisation for
-		 * the future is to make it cached and restrict the shm
-		 * address range.
-		 */
-		add_mapping_pgd(sndphys, rcvvirt, PAGE_SIZE, MAP_SVC_IO_FLAGS,
-			       	receiver->pgd);
-	}
-	return 0;
-}
-
-/* Modifies an address space */
-int sys_space_control(struct syscall_args *regs)
-{
-	unsigned int operation = regs->r0;
-	int err = 0;
-
-	if (current->tid != PAGER_TID) {
-		printk("%s: Priveledged call, only task id %d can call it. (Current id: %d)\n",
-		       __FUNCTION__, current->tid, PAGER_TID);
-		return -EPERM;
-	}
-
-	switch (operation) {
-		case SPCCTRL_SHM:
-			/* FIXME: Add an access check for user space structure */
-			if ((err = do_shm_setup((struct shm_kdata *)&regs->r1) < 0))
-				printk("%s: Error setting up the shm area.\n", __FUNCTION__);
-			break;
-		default:
-			printk("%s: Unsupported operation: %d\n", __FUNCTION__, operation);
-			err = -ENOSYS;
-	}
-	printk("%s called. Tid (%d)\n", __FUNCTION__, current->tid);
-	return err;
-}
-#endif
-
 int sys_space_control(struct syscall_args *regs)
 {
 	return -ENOSYS;

tasks/fs0/main.c

@@ -65,8 +65,10 @@ void handle_fs_requests(void)
 
 	/* Read mrs not used by syslib */
 	for (int i = 0; i < MR_UNUSED_TOTAL; i++)
-		mr[i] = read_mr(i);
+		mr[i] = read_mr(MR_UNUSED_START + i);
 
+	/* FIXME: Fix all these syscalls to read any buffer data from the caller task's utcb.
+	 * Make sure to return -EINVAL if data is not valid. */
 	switch(tag) {
 	case L4_IPC_TAG_WAIT:
 		printf("%s: Synced with waiting thread.\n", __TASKNAME__);

tasks/fs0/src/syscalls.c

@@ -91,7 +91,7 @@ int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
 
 	/* Get the vnode */
 	if (IS_ERR(v = vfs_lookup_bypath(task, pathbuf))) {
-		if (!flags & O_CREAT) {
+		if (!(flags & O_CREAT)) {
 			return (int)v;
 		} else {
 			if ((err = vfs_create(task, pathname, mode)) < 0)
@@ -100,7 +100,7 @@ int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
 	}
 
 	/* Get a new fd */
-	BUG_ON(!(fd = id_new(task->fdpool)));
+	BUG_ON((fd = id_new(task->fdpool)) < 0);
 
 	/* Assign the new fd with the vnode's number */
 	task->fd[fd] = v->vnum;

tasks/fs0/src/task.c

@@ -115,6 +115,7 @@ struct tcb *create_tcb(void)
 	if (!(t = kmalloc(sizeof(*t))))
 		return PTR_ERR(-ENOMEM);
 
+	t->fdpool = id_pool_new_init(TASK_OFILES_MAX);
 	INIT_LIST_HEAD(&t->list);
 	list_add_tail(&t->list, &tcb_head.list);
 	tcb_head.total++;

tasks/libl4/src/init.c

@@ -90,8 +90,8 @@ int utcb_init(void)
 
 		/* Obtain our utcb page address */
 		utcb_page = l4_utcb_page();
-		printf("%s: UTCB Read from mm0 as: 0x%x\n", __FUNCTION__,
-		       (unsigned long)utcb_page);
+		//printf("%s: UTCB Read from mm0 as: 0x%x\n", __FUNCTION__,
+		//       (unsigned long)utcb_page);
 
 		/* Use it as a key to create a shared memory region */
 		BUG_ON((shmid = shmget((key_t)utcb_page,

tasks/libposix/open.c

@@ -35,6 +35,7 @@ static inline int l4_open(const char *pathname, int flags, mode_t mode)
 
 	// write_mr(L4SYS_ARG0, (unsigned long)pathname);
 	copy_to_utcb((void *)pathname, strlen(pathname));
+	write_mr(L4SYS_ARG0, (unsigned long)utcb_page);
 	write_mr(L4SYS_ARG1, flags);
 	write_mr(L4SYS_ARG2, (u32)mode);
 

tasks/mm0/include/vm_area.h

@@ -14,7 +14,7 @@
 #include <arch/mm.h>
 #include <lib/spinlock.h>
 
-#define DEBUG_FAULT_HANDLING
+// #define DEBUG_FAULT_HANDLING
 #ifdef DEBUG_FAULT_HANDLING
 #define dprintf(...)	printf(__VA_ARGS__)
 #else

tasks/mm0/src/init.c

@@ -22,32 +22,32 @@ void init_mm(struct initdata *initdata)
 {
 	/* Initialise the page and bank descriptors */
 	init_physmem(initdata, membank);
-	printf("%s: Initialised physmem.\n", __TASKNAME__);
+	// printf("%s: Initialised physmem.\n", __TASKNAME__);
 
 	/* Initialise the page allocator on first bank. */
 	init_page_allocator(membank[0].free, membank[0].end);
-	printf("%s: Initialised page allocator.\n", __TASKNAME__);
+	// printf("%s: Initialised page allocator.\n", __TASKNAME__);
 
 	/* Initialise the pager's memory allocator */
 	kmalloc_init();
-	printf("%s: Initialised kmalloc.\n", __TASKNAME__);
+	// printf("%s: Initialised kmalloc.\n", __TASKNAME__);
 
 	/* Initialise the zero page */
 	init_devzero();
-	printf("%s: Initialised devzero.\n", __TASKNAME__);
+	// printf("%s: Initialised devzero.\n", __TASKNAME__);
 
 	/* Initialise in-memory boot files */
 	init_boot_files(initdata);
-	printf("%s: Initialised in-memory boot files.\n", __TASKNAME__);
+	// printf("%s: Initialised in-memory boot files.\n", __TASKNAME__);
 
 	shm_init();
-	printf("%s: Initialised shm structures.\n", __TASKNAME__);
+	// printf("%s: Initialised shm structures.\n", __TASKNAME__);
 
 	if (utcb_pool_init() < 0) {
 		printf("UTCB initialisation failed.\n");
 		BUG();
 	}
-	printf("%s: Initialised utcb address pool.\n", __TASKNAME__);
+	// printf("%s: Initialised utcb address pool.\n", __TASKNAME__);
 
 	/* Give the kernel some memory to use for its allocators */
 	l4_kmem_grant(__pfn(alloc_page(__pfn(SZ_1MB))), __pfn(SZ_1MB));

tasks/mm0/src/mmap.c

@@ -564,8 +564,8 @@ int do_mmap(struct vm_file *mapfile, unsigned long file_offset,
 	}
 
 	/* Finished initialising the vma, add it to task */
-	printf("%s: Mapping 0x%x - 0x%x\n", __FUNCTION__,
-	       map_address, map_address + npages * PAGE_SIZE);
+	dprintf("%s: Mapping 0x%x - 0x%x\n", __FUNCTION__,
+		map_address, map_address + npages * PAGE_SIZE);
 	list_add(&new->list, &task->vm_area_list);
 
 	return 0;

tasks/mm0/src/task.c

@@ -34,6 +34,15 @@ struct tcb_head {
 	int total;			/* Total threads */
 } tcb_head;
 
+void print_tasks(void)
+{
+	struct tcb *task;
+	printf("Tasks:\n========\n");
+	list_for_each_entry(task, &tcb_head.list, list) {
+		printf("Task tid: %d, spid: %d\n", task->tid, task->spid);
+	}
+}
+
 struct tcb *find_task(int tid)
 {
 	struct tcb *t;
@@ -73,14 +82,12 @@ struct tcb *task_create(struct task_ids *ids)
 	int err;
 
 	/* Create the thread structures and address space */
-	printf("Creating new thread with ids: %d, %d.\n", ids->tid, ids->spid);
 	if ((err = l4_thread_control(THREAD_CREATE, ids)) < 0) {
 		printf("l4_thread_control failed with %d.\n", err);
 		return PTR_ERR(err);
 	}
 
 	/* Create a task and use given space and thread ids. */
-	printf("New task with id: %d, space id: %d\n", ids->tid, ids->spid);
 	if (IS_ERR(task = tcb_alloc_init()))
 		return PTR_ERR(task);
 
@@ -195,7 +202,7 @@ int task_start(struct tcb *task, struct task_ids *ids)
 	int err;
 
 	/* Start the thread */
-	printf("Starting task with id %d\n", task->tid);
+	printf("Starting task with id %d, spid: %d\n", task->tid, task->spid);
 	if ((err = l4_thread_control(THREAD_RUN, ids)) < 0) {
 		printf("l4_thread_control failed with %d\n", err);
 		return err;
@@ -409,7 +416,7 @@ struct vm_file *initdata_next_bootfile(struct initdata *initdata)
  */
 int start_boot_tasks(struct initdata *initdata)
 {
-	struct vm_file *file, *fs0, *mm0, *n;
+	struct vm_file *file = 0, *fs0 = 0, *mm0 = 0, *n;
 	struct svc_image *img;
 	struct task_ids ids;
 	struct list_head files;
@@ -438,7 +445,7 @@ int start_boot_tasks(struct initdata *initdata)
 	/* MM0 needs partial initialisation, since its already running. */
 	printf("%s: Initialising mm0 tcb.\n", __TASKNAME__);
 	ids.tid = PAGER_TID;
-	ids.tid = PAGER_TID;
+	ids.spid = PAGER_TID;
 	if (mm0_task_init(mm0, INITTASK_AREA_START, INITTASK_AREA_END, &ids) < 0)
 		BUG();
 	total++;
@@ -460,14 +467,6 @@ int start_boot_tasks(struct initdata *initdata)
 			BUG();
 		total++;
 	}
-	{
-		struct tcb *t;
-		printf("Tasks:\n========\n");
-		list_for_each_entry(t, &tcb_head.list, list) {
-			printf("Task tid: %d, spid: %d\n", t->tid, t->spid);
-			BUG_ON(t->tid != t->spid);
-		}
-	}
 
 	if (!total) {
 		printf("%s: Could not start any tasks.\n", __TASKNAME__);