void init_startup_thread(uint32_t arg)
{
/* Threads have arguments for functions they run, we don't
need any. Silence the compiler warning by using the argument. */
arg = arg;
kprintf("Mounting filesystems\n");
vfs_mount_all();
kprintf("Initializing networking\n");
network_init();
if(bootargs_get("initprog") == NULL) {
kprintf("No initial program (initprog), dropping to fallback\n");
init_startup_fallback();
}
kprintf("Starting initial program '%s'\n", bootargs_get("initprog"));
/* `process_start` no longer takes an executable as its argument, so we need
to start initprog with `process_spawn`. */
process_id_t pid = process_spawn(bootargs_get("initprog"));
if (pid < 0) {
KERNEL_PANIC("Couldn't fit initial program in process table.\n");
}
process_join(pid);
/* The current process_start() should never return. */
KERNEL_PANIC("Run out of initprog.\n");
}
// send terminate signal to process
void tlb_modified_exception(void) {
tlb_exception_state_t tlb_es;
_tlb_get_exception_state(&tlb_es);
pagetable_t *current_pagetable;
current_pagetable = thread_get_current_thread_entry()->pagetable;
if (current_pagetable == NULL) {
KERNEL_PANIC("Pagetable is non-existing");
}
uint32_t i;
for (i = 0; i < current_pagetable->valid_count; i++) {
tlb_entry_t *entry = ¤t_pagetable->entries[i];
// find addr fra pagetable og put i tlb.
if (entry->VPN2 == tlb_es.badvpn2) {
/* Checks if address is odd( see vm.c)
* and thereafter checks validbit */
if (ADDR_IS_ON_ODD_PAGE(entry->VPN2)){
KERNEL_ASSERT(entry->D1);
} else {
KERNEL_ASSERT(entry->D0);
}
return;
}
}
KERNEL_PANIC("Unhandled TLB modified exception");
}
/** Initializes interrupt handling. Allocates interrupt stacks for
* each processor, initializes the interrupt vectors and initializes
* the registered interrupt handler table.
*
* @param num_cpus Number of CPUs in the system
*/
void interrupt_init(int num_cpus) {
int i;
uint32_t *iv_area1 = (uint32_t *)INTERRUPT_VECTOR_ADDRESS1;
uint32_t *iv_area2 = (uint32_t *)INTERRUPT_VECTOR_ADDRESS2;
uint32_t *iv_area3 = (uint32_t *)INTERRUPT_VECTOR_ADDRESS3;
uint32_t ret;
if (num_cpus < 1 || num_cpus > CONFIG_MAX_CPUS)
KERNEL_PANIC("Too few or many CPUs found");
/* Allocate interrupt stacks for each processor */
for(i = 0; i < num_cpus; i++) {
ret = (uint32_t)kmalloc(PAGE_SIZE);
if (ret == 0)
KERNEL_PANIC("Unable to allocate interrupt stacks");
interrupt_stacks[i] = ret+PAGE_SIZE-4;
}
/* Copy the interrupt vector code to its positions.All vectors
* will contain the same code.
*/
for(i = 0 ; i < INTERRUPT_VECTOR_LENGTH ; i++) {
iv_area1[i] = ((uint32_t *) &_cswitch_vector_code)[i];
iv_area2[i] = ((uint32_t *) &_cswitch_vector_code)[i];
iv_area3[i] = ((uint32_t *) &_cswitch_vector_code)[i];
}
/* Initialize the handler table to empty */
for (i=0; i<CONFIG_MAX_DEVICES; i++) {
interrupt_handlers[i].device = NULL;
interrupt_handlers[i].irq = 0;
interrupt_handlers[i].handler = NULL;
}
}
/**
* Allocates permanent memory for the kernel in unmapped memory. Call
* of this function after virtual memory has been initialized will
* cause kernel panic. Panics if memory can't be allocated.
*
* @param bytes The number of bytes to be allocated.
*
* @return The start address of the reseved memory address.
*/
void *kmalloc(int bytes)
{
uint32_t res;
/* Panic if VM is initialized */
if (free_area_start == 0xffffffff){
KERNEL_PANIC("Attempting to use kmalloc after vm init\n");
}
if (free_area_start == 0) {
KERNEL_PANIC("Attempting to use kmalloc before initialization\n");
}
/* bytes == 0 may be useful for aligning memory so it is allowed */
if (bytes < 0)
KERNEL_PANIC("Attempting to kmalloc negative amount of bytes\n");
if (free_area_start + bytes > memory_end)
KERNEL_PANIC("Out of memory\n");
res = free_area_start;
free_area_start += bytes;
/* Check that the start of free area is aligned on a word
boundary */
if (free_area_start & 0x03) {
free_area_start += 4;
free_area_start &= 0xfffffffc;
}
return (void *)res;
}
/** Registers an interrupt handler for one or more interrupts
* (IRQs). When registered, a \texttt{handler(device)} function call
* will be made if any of the interrupts in \texttt{irq} occured.
*
* @param irq Mask of interrupts this handler wants to handle
* @param handler The interrupt handling function
* @param device The device registered for the interrupt, will be
* given as a parameter for handler
*/
void interrupt_register(uint32_t irq,
void (*handler)(device_t *),
device_t *device)
{
int i = 0;
/* Check that IRQ mask is sane */
if ((irq & ~(uint32_t)INTERRUPT_MASK_ALL)!= 0) {
kprintf("Unsupported IRQ mask:%.8x\n", irq);
KERNEL_PANIC("interrupt_register");
}
/* No need for spinlock, this should not be called after other CPUs
* are enabled.
*/
while (interrupt_handlers[i].device != NULL && i < CONFIG_MAX_DEVICES) i++;
if (i >= CONFIG_MAX_DEVICES)
KERNEL_PANIC("Interrupt handler table is full");
interrupt_handlers[i].device = device;
interrupt_handlers[i].irq = irq;
interrupt_handlers[i].handler = handler;
}
/**
* Gets one request from request queue and puts the disk in
* work. Assumes that interrupts are disabled and device spinlock is
* held. Also assumes that the device is idle.
*
* @param gbd pointer to the general block device.
*/
static void disk_next_request(gbd_t *gbd) {
disk_real_device_t *real_dev = gbd->device->real_device;
disk_io_area_t *io = (disk_io_area_t *)gbd->device->io_address;
volatile gbd_request_t *req;
KERNEL_ASSERT(!(DISK_STATUS_RBUSY(io->status) ||
DISK_STATUS_WBUSY(io->status)));
KERNEL_ASSERT(real_dev->request_served == NULL);
req = real_dev->request_queue;
if(req == NULL) {
/* There were no requests. */
return;
}
real_dev->request_queue = req->next;
req->next = NULL;
real_dev->request_served = req;
io->tsector = req->block;
io->dmaaddr = (uint32_t)req->buf;
if(req->operation == GBD_OPERATION_READ) {
io->command = DISK_COMMAND_READ;
} else if(req->operation == GBD_OPERATION_WRITE) {
io->command = DISK_COMMAND_WRITE;
} else {
KERNEL_PANIC("disk_next_request: Unknown gbd operation.");
}
if(DISK_STATUS_ERRORS(io->status)) {
kprintf("disk error: 0x%8.8x\n", DISK_STATUS_ERRORS(io->status));
KERNEL_PANIC("disk error occured");
}
}
/**
* Initializes interrupt driven tty driver. Memory is reserved for
* data structures and tty interrupt handler is registerded.
*
* @param desc Pointer to a YAMS device descriptor data structure.
*
* @return Pointer to tty's device_t structure.
*/
device_t *tty_init(io_descriptor_t *desc) {
device_t *dev;
gcd_t *gcd;
tty_real_device_t *tty_rd;
uint32_t irq_mask;
static int num_of_inits = 0;
dev = (device_t*)stalloc(sizeof(device_t));
if(dev == NULL)
KERNEL_PANIC("Could not reserve memory for tty driver.");
gcd = (gcd_t*)stalloc(sizeof(gcd_t));
if(gcd == NULL)
KERNEL_PANIC("Could not reserve memory for tty driver.");
dev->generic_device = gcd;
dev->io_address = desc->io_area_base;
dev->type = desc->type;
gcd->device = dev;
gcd->write = tty_write;
gcd->read = tty_read;
tty_rd = (tty_real_device_t*)stalloc(sizeof(tty_real_device_t));
if(tty_rd == NULL)
KERNEL_PANIC("Could not reserve memory for tty driver.");
dev->real_device = tty_rd;
if (num_of_inits == 0) {
/* First tty driver will share the device with the polling TTY.
* That is, we use the same spinlock with it. (The spinlock is
* kprintf's because that is the only proper way to access the
* polling tty.) */
tty_rd->slock = &kprintf_slock;
} else {
tty_rd->slock = (spinlock_t*)stalloc(sizeof(spinlock_t));
if(tty_rd->slock == NULL)
KERNEL_PANIC("Could not reserve memory for tty driver spinlock.");
spinlock_reset(tty_rd->slock);
}
num_of_inits++;
tty_rd->write_head = 0;
tty_rd->write_count = 0;
tty_rd->read_head = 0;
tty_rd->read_count = 0;
irq_mask = 1 << (desc->irq + 10);
interrupt_register(irq_mask, tty_interrupt_handle, dev);
return dev;
}
void thread_goto_userland(context_t *usercontext)
{
/* Call platform-specific */
_context_enter_userland(usercontext);
KERNEL_PANIC("Userland entering returned for unknown reason.");
}
void init_startup_thread(uint32_t arg)
{
/* Threads have arguments for functions they run, we don't
need any. Silence the compiler warning by using the argument. */
arg = arg;
process_id_t pid;
kprintf("Mounting filesystems\n");
vfs_mount_all();
kprintf("Initializing networking\n");
network_init();
if(bootargs_get("initprog") == NULL) {
kprintf("No initial program (initprog), dropping to fallback\n");
init_startup_fallback();
}
kprintf("Starting initial program '%s'\n", bootargs_get("initprog"));
pid = process_spawn(bootargs_get("initprog"));
if (pid < 0)
KERNEL_PANIC("Couldn't fit initial program in process table.\n");
process_join(pid);
halt_kernel();
}
void tlb_common_exception(void) {
tlb_exception_state_t tlb_es;
_tlb_get_exception_state(&tlb_es);
pagetable_t *current_pagetable;
current_pagetable = thread_get_current_thread_entry()->pagetable;
if (current_pagetable == NULL) {
KERNEL_PANIC("Pagetable is non-existing");
}
uint32_t i;
for (i = 0; i < current_pagetable->valid_count; i++) {
tlb_entry_t *entry = ¤t_pagetable->entries[i];
// find addr fra pagetable og put i tlb.
if (entry->VPN2 == tlb_es.badvpn2) {
KERNEL_ASSERT(entry->VPN2 == tlb_es.badvaddr >> 13);
/* Checks if address is odd( see vm.c)
* and thereafter checks validbit */
if (ADDR_IS_ON_ODD_PAGE(tlb_es.badvaddr)){
KERNEL_ASSERT(entry->V1);
} else {
KERNEL_ASSERT(entry->V0);
}
// Inserting into a random entry of the tlb.
_tlb_write_random(¤t_pagetable->entries[i]);
return;
}
}
/**
* Initialize disk device driver. Reserves memory for data structures
* and register driver to the interrupt handler.
*
* @param desc Pointer to the YAMS IO device descriptor of the disk
*
* @return Pointer to the device structure of the disk
*/
device_t *disk_init(io_descriptor_t *desc) {
device_t *dev;
gbd_t *gbd;
disk_real_device_t *real_dev;
uint32_t irq_mask;
dev = (device_t*)stalloc(sizeof(device_t));
gbd = (gbd_t*)stalloc(sizeof(gbd_t));
real_dev = (disk_real_device_t*)stalloc(sizeof(disk_real_device_t));
if (dev == NULL || gbd == NULL || real_dev == NULL)
KERNEL_PANIC("Could not allocate memory for disk driver.");
dev->generic_device = gbd;
dev->real_device = real_dev;
dev->descriptor = desc;
dev->io_address = desc->io_area_base;
dev->type = desc->type;
gbd->device = dev;
gbd->read_block = disk_read_block;
gbd->write_block = disk_write_block;
gbd->block_size = disk_block_size;
gbd->total_blocks = disk_total_blocks;
spinlock_reset(&real_dev->slock);
real_dev->request_queue = NULL;
real_dev->request_served = NULL;
irq_mask = 1 << (desc->irq + 10);
interrupt_register(irq_mask, disk_interrupt_handle, dev);
return dev;
}
/**
* Handle system calls. Interrupts are enabled when this function is
* called.
*
* @param user_context The userland context (CPU registers as they
* where when system call instruction was called in userland)
*/
void syscall_handle(context_t *user_context)
{
/* When a syscall is executed in userland, register a0 contains
* the number of the syscall. Registers a1, a2 and a3 contain the
* arguments of the syscall. The userland code expects that after
* returning from the syscall instruction the return value of the
* syscall is found in register v0. Before entering this function
* the userland context has been saved to user_context and after
* returning from this function the userland context will be
* restored from user_context.
*/
switch(user_context->cpu_regs[MIPS_REGISTER_A0]) {
case SYSCALL_HALT:
halt_kernel();
break;
case SYSCALL_READ:
user_context->cpu_regs[MIPS_REGISTER_V0] =
read(user_context->cpu_regs[MIPS_REGISTER_A1]
,(void*)user_context->cpu_regs[MIPS_REGISTER_A2]
,user_context->cpu_regs[MIPS_REGISTER_A3]);
break;
case SYSCALL_WRITE:
// TODO
user_context->cpu_regs[MIPS_REGISTER_V0] =
write(user_context->cpu_regs[MIPS_REGISTER_A1]
,(void*)user_context->cpu_regs[MIPS_REGISTER_A2]
,user_context->cpu_regs[MIPS_REGISTER_A3]);
break;
default:
KERNEL_PANIC("Unhandled system call\n");
}
/* Move to next instruction after system call */
user_context->pc += 4;
}
/**
* Handle system calls. Interrupts are enabled when this function is
* called.
*
* @param user_context The userland context (CPU registers as they
* where when system call instruction was called in userland)
*/
void syscall_handle(context_t *user_context)
{
/* When a syscall is executed in userland, register a0 contains
* the number of the syscall. Registers a1, a2 and a3 contain the
* arguments of the syscall. The userland code expects that after
* returning from the syscall instruction the return value of the
* syscall is found in register v0. Before entering this function
* the userland context has been saved to user_context and after
* returning from this function the userland context will be
* restored from user_context.
*/
int retval;
switch(user_context->cpu_regs[MIPS_REGISTER_A0]) {
case SYSCALL_HALT:
halt_kernel();
break;
case SYSCALL_EXEC:
retval = (int) process_spawn((char*) user_context->cpu_regs[MIPS_REGISTER_A1]);
user_context->cpu_regs[MIPS_REGISTER_V0] = retval;
break;
case SYSCALL_EXIT:
/* Resources are cleaned up in process_finish(...) */
process_finish(user_context->cpu_regs[MIPS_REGISTER_A1]);
break;
case SYSCALL_JOIN:
retval = process_join(user_context->cpu_regs[MIPS_REGISTER_A1]);
user_context->cpu_regs[MIPS_REGISTER_V0] = retval;
break;
case SYSCALL_READ:
{
int fhandle = user_context->cpu_regs[MIPS_REGISTER_A1];
int buffer = user_context->cpu_regs[MIPS_REGISTER_A2];
int length = user_context->cpu_regs[MIPS_REGISTER_A3];
int retval = syscall_read(fhandle, (void *)buffer, length);
user_context->cpu_regs[MIPS_REGISTER_V0] = retval;
}
break;
case SYSCALL_WRITE:
{
int fhandle = user_context->cpu_regs[MIPS_REGISTER_A1];
int buffer = user_context->cpu_regs[MIPS_REGISTER_A2];
int length = user_context->cpu_regs[MIPS_REGISTER_A3];
int retval = syscall_write(fhandle, (void *)buffer, length);
user_context->cpu_regs[MIPS_REGISTER_V0] = retval;
}
break;
default:
KERNEL_PANIC("Unhandled system call\n");
}
/* Move to next instruction after system call */
user_context->pc += 4;
}
void thread_goto_userland(context_t *usercontext)
{
/* Set userland bit and enable interrupts before entering userland. */
usercontext->status = usercontext->status | USERLAND_ENABLE_BIT;
usercontext->status = usercontext->status | INTERRUPT_MASK_ALL;
usercontext->status = usercontext->status | INTERRUPT_MASK_MASTER;
_cswitch_to_userland(usercontext);
KERNEL_PANIC("Userland entering returned for unknown reason.");
}
uint32_t syscall_read(uint32_t fd, char* s, int len)
{
int count = 0;
gcd_t *gcd;
if (fd != FILEHANDLE_STDIN) {
KERNEL_PANIC("Can only read() from standard input.");
}
gcd = process_get_current_process_entry()->fds[0];
count = gcd->read(gcd, s, len);
return count;
}
/** Initializes the (software) shutdown device. Note that the system
* should have only one shutdown device.
*
* @param desc Pointer to the YAMS IO device descriptor of the shutdown device
* @return Pointer to the device structure of the shutdown device
*/
device_t *shutdown_init(io_descriptor_t *desc)
{
if (shutdown_init_done)
KERNEL_PANIC("Hardware failure: multiple SHUTDOWN devices");
shutdown_init_done = 1;
fill_device_t(desc, &system_shutdown);
return &system_shutdown;
}
uint32_t syscall_write(uint32_t fd, char* s, int len)
{
int count;
gcd_t *gcd;
if (fd != FILEHANDLE_STDOUT) {
KERNEL_PANIC("Can only write() to standard output.");
}
gcd = process_get_current_process_entry()->fds[1];
count = gcd->write(gcd, s, len);
return count;
}
/** Handles an interrupt (exception code 0). All interrupt handlers
* that are registered for any of the occured interrupts (hardware
* 0-5, software 0-1) are called. The scheduler is called if a timer
* interrupt (hardware 5) or a context switch request (software
* interrupt 0) occured, or if the currently running thread for the
* processor is the idle thread.
*
* @param cause The Cause register from CP0
*/
void interrupt_handle(uint32_t cause) {
int this_cpu, i;
if(cause & INTERRUPT_CAUSE_SOFTWARE_0) {
_interrupt_clear_sw0();
}
this_cpu = _interrupt_getcpu();
/* Exceptions should be handled elsewhere: */
if((cause & 0x0000007c) != 0) {
kprintf("Caught exception, cause %.8x, CPU %i\n", cause, this_cpu);
KERNEL_PANIC("Exception in interrupt_handle");
}
/* Call appropiate interrupt handlers. Handlers cannot be
* unregistered, so after the first empty * entry all others are
* also empty.
*/
for (i=0; i<CONFIG_MAX_DEVICES; i++) {
if (interrupt_handlers[i].device == NULL)
break;
/* If this handler is registered for any of the interrupts
* that occured, call it.
*/
if ((cause & interrupt_handlers[i].irq) != 0)
interrupt_handlers[i].handler(interrupt_handlers[i].device);
}
/* Timer interrupt (HW5) or requested context switch (SW0)
* Also call scheduler if we're running the idle thread.
*/
if((cause & (INTERRUPT_CAUSE_SOFTWARE_0 |
INTERRUPT_CAUSE_HARDWARE_5)) ||
scheduler_current_thread[this_cpu] == IDLE_THREAD_TID) {
scheduler_schedule();
/* Until we have proper VM we must manually fill
the TLB with pagetable entries before running code using
given pagetable. Note that this method limits pagetable
rows (possible mapping pairs) to 16 and can't be used
with proper pagetables and VM.
Note that if you remove this call (which you probably do when
you implement proper VM), you must manually call _tlb_set_asid
here. See the implementation of tlb_fill on details how to do that.
*/
_tlb_set_asid(thread_get_current_thread());
}
}
/** Initializes the RTC (Real Time Clock) device. Note that the system
* should have only one RTC.
*
* @param desc Pointer to the YAMS IO device descriptor of the RTC
* @return Pointer to the device structure of the RTC
*/
device_t *rtc_init(io_descriptor_t *desc)
{
static int init_done = 0;
if (init_done)
KERNEL_PANIC("Hardware failure: multiple RTC devices");
init_done = 1;
fill_device_t(desc, &system_rtc);
return &system_rtc;
}
void tlb_seek_insert(void)
{
tlb_exception_state_t state;
_tlb_get_exception_state(&state);
pagetable_t *table = thread_get_current_thread_entry()->pagetable;
for (int i = 0; i < (int)table->valid_count; i++) {
if (table->entries[i].VPN2 == state.badvpn2) {
_tlb_write_random(&table->entries[i]);
return;
}
}
KERNEL_PANIC("Access violation");
}
/** Initializes the system memory information (meminfo) device. Note
* that the system should have only one meminfo device.
*
* @param desc Pointer to the YAMS IO device descriptor of the meminfo device
* @return Pointer to the device structure of the meminfo device
*/
device_t *meminfo_init(io_descriptor_t *desc)
{
static int init_done = 0;
if (init_done)
KERNEL_PANIC("Hardware failure: multiple MEMINFO devices");
init_done = 1;
fill_device_t(desc, &system_meminfo);
return &system_meminfo;
}
physaddr_t physmem_allocblocks(uint32_t count)
{
/* Get spinlock */
physaddr_t addr = 0, i;
interrupt_status_t intr_status = _interrupt_disable();
spinlock_acquire(physmem_lock);
/* Sanity */
if(used_blocks >= total_blocks)
{
/* PANIC AT THE DISCO ! */
KERNEL_PANIC("Physical Manager >> OUT OF MEMORY");
}
/* Get a frame */
int64_t frame = physmem_getframes(count);
if(frame == -1)
{
/* PANIC AT THE DISCO ! */
spinlock_release(physmem_lock);
KERNEL_PANIC("Physical Manager >> OUT OF MEMORY");
}
/* Mark it used */
for(i = 0; i < count; i++)
memmap_setbit(frame + i);
/* Release spinlock */
spinlock_release(physmem_lock);
_interrupt_set_state(intr_status);
/* Calculate Address */
addr = (uint64_t)(frame * PMM_BLOCK_SIZE);
used_blocks++;
return addr;
}
/* Writes length bytes from buffer to the open file identified by
filehandle, starting at the current position and advancing the
position. Returns the number of bytes actually written, or a
negative value on error. */
int syscall_write(uint32_t fd, char *s, int len)
{
gcd_t *gcd;
device_t *dev;
if (fd == FILEHANDLE_STDOUT || fd == FILEHANDLE_STDERR)
{
dev = device_get(YAMS_TYPECODE_TTY, 0);
gcd = (gcd_t *)dev->generic_device;
return gcd->write(gcd, s, len);
} else {
KERNEL_PANIC("Write syscall not finished yet.");
return 0;
}
}
/**
* TTY's interrupt handler. Functinality depends on status of TTY's
* status port. On WIRQ status writes internal buffer from
* tty_real_device_t data structure to data port. On RIRQ
* status reads data from data port to the internal buffer.
* Implements read from the gbd interface.
*
* @param device Pointer to the TTY device.
*/
void tty_interrupt_handle(device_t *device) {
volatile tty_io_area_t *iobase = (tty_io_area_t *)device->io_address;
volatile tty_real_device_t *tty_rd
= (tty_real_device_t *)device->real_device;
if(TTY_STATUS_WIRQ(iobase->status)) {
spinlock_acquire(tty_rd->slock);
iobase->command = TTY_COMMAND_WIRQD;
iobase->command = TTY_COMMAND_WIRQ;
while(!TTY_STATUS_WBUSY(iobase->status) && tty_rd->write_count > 0) {
iobase->command = TTY_COMMAND_WIRQ;
iobase->data = tty_rd->write_buf[tty_rd->write_head];
tty_rd->write_head = (tty_rd->write_head + 1) % TTY_BUF_SIZE;
tty_rd->write_count--;
}
iobase->command = TTY_COMMAND_WIRQE;
if (tty_rd->write_count == 0)
sleepq_wake_all((void *)tty_rd->write_buf);
spinlock_release(tty_rd->slock);
}
if(TTY_STATUS_RIRQ(iobase->status)) {
spinlock_acquire(tty_rd->slock);
iobase->command = TTY_COMMAND_RIRQ;
if (TTY_STATUS_ERROR(iobase->status))
KERNEL_PANIC("Could not issue RIRQ to TTY.");
while (TTY_STATUS_RAVAIL(iobase->status)) {
char data = iobase->data;
int index;
if (tty_rd->read_count > TTY_BUF_SIZE)
continue;
index = (tty_rd->read_head + tty_rd->read_count) % TTY_BUF_SIZE;
tty_rd->read_buf[index] = data;
tty_rd->read_count++;
}
spinlock_release(tty_rd->slock);
sleepq_wake_all((void *)tty_rd->read_buf);
}
}
/* A helper to the init functions. Fills the given device structure to
* values from the given IO descriptor and uses "null" values for the
* rest. Allocates memory for the structure if it was given as NULL
*/
static device_t *fill_device_t(io_descriptor_t *desc, device_t *dev)
{
if (dev == NULL)
dev = kmalloc(sizeof(device_t));
if (dev == NULL)
KERNEL_PANIC("Run out ouf memory when allocating struct"
" for a metadevice");
dev->real_device = NULL;
dev->generic_device = NULL;
dev->descriptor = desc;
dev->io_address = desc->io_area_base;
dev->type = desc->type;
return dev;
}
/**
* Writes at most length bytes from the specified buffer to the file identified
* by filehandle, starting at the current position, and advancing the position.
*
* @return The number of bytes actually written. It is invalid to write to
* FILEHANDLE_STDIN. In this case, VFS_INVALID_PARAMS is returned.
*/
int io_write(int file, void* buffer, int length)
{
int res;
// Don't pipe if writing to std
if (file > 2) {
// Get the pipe for the file
pipe_t *pipe = pipe_get_pipe(file);
// Don't read to empty pipes
if (pipe == NULL) {
KERNEL_PANIC("Cannot write from empty pipe\n");
}
// Get the read end and update the file
file = pipe->write_end;
// Write to the pipe buffer
pipe_write(buffer, length, pipe);
}
switch(file) {
case FILEHANDLE_STDIN:
res = VFS_INVALID_PARAMS;
break;
case FILEHANDLE_STDOUT:
res = tty_write_stdout(buffer, length);
break;
case FILEHANDLE_STDERR:
res = tty_write_stderr(buffer, length);
break;
default:
file -= 3;
if (!process_has_open_file(file)) {
res = VFS_NOT_OPEN_IN_PROCESS;
} else {
res = vfs_write(file, buffer, length);
}
}
//
return res;
}
int syscall_close(openfile_t file) {
int result = vfs_close(file - 2);
if (result < 0) {
switch(result) {
case VFS_UNUSABLE:
kprintf("Error closing file. File system unusable.\n");
break;
case VFS_NOT_OPEN:
kprintf("Error closing file: File not open\n");
break;
default:
kprintf("Error closing file: unknown error\n");
break;
}
KERNEL_PANIC("Error closing file");
}
return result;
}
/**
* Sets the given bit in the bitmap.
*
* @param bitmap The bitmap
*
* @param pos The index of the bit to set
*
* @param value The new value of the given bit. Valid values are 0 and
* 1.
*/
void bitmap_set(bitmap_t *bitmap, int pos, int value)
{
int i;
int j;
KERNEL_ASSERT(pos >= 0);
i = pos / 32;
j = pos % 32;
if (value == 0) {
bitmap[i] = bitmap[i] & ~(1 << j);
} else if (value == 1) {
bitmap[i] = bitmap[i] | (1 << j);
} else {
KERNEL_PANIC("bit value other than 0 or 1");
}
}
/**
* Handle system calls. Interrupts are enabled when this function is
* called.
*
* @param user_context The userland context (CPU registers as they
* where when system call instruction was called in userland)
*/
void syscall_handle(context_t *user_context)
{
int A1 = user_context->cpu_regs[MIPS_REGISTER_A1];
int A2 = user_context->cpu_regs[MIPS_REGISTER_A2];
int A3 = user_context->cpu_regs[MIPS_REGISTER_A3];
/* When a syscall is executed in userland, register a0 contains
* the number of the syscall. Registers a1, a2 and a3 contain the
* arguments of the syscall. The userland code expects that after
* returning from the syscall instruction the return value of the
* syscall is found in register v0. Before entering this function
* the userland context has been saved to user_context and after
* returning from this function the userland context will be
* restored from user_context.
*/
switch(user_context->cpu_regs[MIPS_REGISTER_A0]) {
case SYSCALL_HALT:
halt_kernel();
break;
case SYSCALL_EXIT:
syscall_exit(A1);
break;
case SYSCALL_WRITE:
user_context->cpu_regs[MIPS_REGISTER_V0] =
syscall_write(A1, (char *)A2, A3);
break;
case SYSCALL_READ:
user_context->cpu_regs[MIPS_REGISTER_V0] =
syscall_read(A1, (char *)A2, A3);
break;
case SYSCALL_JOIN:
user_context->cpu_regs[MIPS_REGISTER_V0] =
syscall_join(A1);
break;
case SYSCALL_EXEC:
user_context->cpu_regs[MIPS_REGISTER_V0] =
syscall_exec((char *)A1);
break;
default:
KERNEL_PANIC("Unhandled system call\n");
}
/* Move to next instruction after system call */
user_context->pc += 4;
}
void tlb_load_exception(void)
{
// kprintf("STOREAH");
tlb_exception_state_t state;
pagetable_t* pagetable;
//fylder en state på vores state.
_tlb_get_exception_state(&state);
pagetable = thread_get_current_thread_entry()->pagetable;
_tlb_probe(pagetable->entries);
if(tlb_index < 0) {
KERNEL_PANIC("pagetable not found!");
}
for(uint32_t i = 0; i < pagetable->valid_count; i++) {
_tlb_write_random((tlb_entry_t*) &pagetable->entries[i]);
}
}