Kernel: Update signal handling and IPC

14 files changed, 470 insertions, 15 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index c9fffe6..ea8781c 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -1,6 +1,6 @@
 CC="i686-sb-gcc"
 AS="i686-sb-as"
-OBJ = arch/i386/boot.o init/kernel.o cpu/gdt.o cpu/reload_gdt.o cpu/idt.o cpu/io.o libc/stdio/print.o drivers/keyboard.o log.o drivers/pit.o libc/string/memcpy.o libc/string/strlen.o libc/string/memcmp.o drivers/ata.o libc/string/memset.o cpu/syscall.o  read_eip.o libc/exit/assert.o process.o libc/string/strcpy.o arch/i386/mmu.o kmalloc.o fs/ext2.o fs/vfs.o fs/devfs.o cpu/spinlock.o random.o libc/string/strcmp.o crypto/ChaCha20/chacha20.o crypto/SHA1/sha1.o fs/tmpfs.o libc/string/isequal.o drivers/pst.o halts.o syscalls/ppoll.o syscalls/ftruncate.o kubsan.o syscalls/mmap.o drivers/serial.o syscalls/accept.o syscalls/bind.o syscalls/socket.o socket.o poll.o fs/fifo.o hashmap/hashmap.o fs/shm.o syscalls/shm.o elf.o ksbrk.o sched/scheduler.o syscalls/stat.o libc/string/copy.o libc/string/strncpy.o drivers/mouse.o libc/string/strlcpy.o libc/string/strcat.o drivers/vbe.o syscalls/msleep.o syscalls/uptime.o syscalls/mkdir.o drivers/pci.o drivers/rtl8139.o network/ethernet.o network/arp.o network/bytes.o network/ipv4.o network/udp.o syscalls/recvfrom.o math.o syscalls/sendto.o signal.o syscalls/kill.o syscalls/sigaction.o network/tcp.o drivers/ahci.o crypto/xoshiro256plusplus/xoshiro256plusplus.o syscalls/chdir.o syscalls/getcwd.o syscalls/isatty.o syscalls/randomfill.o syscalls/open.o syscalls/write.o syscalls/pwrite.o ipc.o syscalls/ipc.o syscalls/port.o syscalls/map_frames.o syscalls/virtual_to_physical.o syscalls/install_irq.o switch_task.o arch/i386/interrupts.o cpu/isr.o
+OBJ = arch/i386/boot.o init/kernel.o cpu/gdt.o cpu/reload_gdt.o cpu/idt.o cpu/io.o libc/stdio/print.o drivers/keyboard.o log.o drivers/pit.o libc/string/memcpy.o libc/string/strlen.o libc/string/memcmp.o drivers/ata.o libc/string/memset.o cpu/syscall.o  read_eip.o libc/exit/assert.o process.o libc/string/strcpy.o arch/i386/mmu.o kmalloc.o fs/ext2.o fs/vfs.o fs/devfs.o cpu/spinlock.o random.o libc/string/strcmp.o crypto/ChaCha20/chacha20.o crypto/SHA1/sha1.o fs/tmpfs.o libc/string/isequal.o drivers/pst.o halts.o syscalls/ppoll.o syscalls/ftruncate.o kubsan.o syscalls/mmap.o drivers/serial.o syscalls/accept.o syscalls/bind.o syscalls/socket.o socket.o poll.o fs/fifo.o hashmap/hashmap.o fs/shm.o syscalls/shm.o elf.o ksbrk.o sched/scheduler.o syscalls/stat.o libc/string/copy.o libc/string/strncpy.o drivers/mouse.o libc/string/strlcpy.o libc/string/strcat.o drivers/vbe.o syscalls/msleep.o syscalls/uptime.o syscalls/mkdir.o drivers/pci.o drivers/rtl8139.o network/ethernet.o network/arp.o network/bytes.o network/ipv4.o network/udp.o syscalls/recvfrom.o math.o syscalls/sendto.o signal.o syscalls/kill.o syscalls/sigaction.o network/tcp.o drivers/ahci.o crypto/xoshiro256plusplus/xoshiro256plusplus.o syscalls/chdir.o syscalls/getcwd.o syscalls/isatty.o syscalls/randomfill.o syscalls/open.o syscalls/write.o syscalls/pwrite.o ipc.o syscalls/ipc.o syscalls/port.o syscalls/map_frames.o syscalls/virtual_to_physical.o syscalls/install_irq.o arch/i386/interrupts.o cpu/isr.o lib/stack.o
 CFLAGS = -O0 -fsanitize=vla-bound,shift-exponent,pointer-overflow,shift,signed-integer-overflow,bounds -ggdb -ffreestanding -Wall -Werror -mgeneral-regs-only -Wimplicit-fallthrough -I./libc/include/ -I. -Wno-pointer-sign -DKERNEL
 #LDFLAGS=-flto -Ofast
 LDFLAGS=
diff --git a/kernel/cpu/idt.c b/kernel/cpu/idt.c
index 823cc2a..30b6253 100644
--- a/kernel/cpu/idt.c
+++ b/kernel/cpu/idt.c
@@ -76,10 +76,9 @@ void page_fault(reg_t *regs) {
   volatile uint32_t cr2;
   asm volatile("mov %%cr2, %0" : "=r"(cr2));
   kprintf("CR2: %x\n", cr2);
-  if (0xFFFFDEAD == cr2) {
-    for (;;) {
-      switch_task(0);
-    }
+  if (0xDEADC0DE == cr2) {
+    EOI(0xB);
+    process_pop_restore_context(NULL, regs);
     return;
   }
   klog("Page Fault", LOG_ERROR);
@@ -219,16 +218,42 @@ void *isr_list[] = {
     isr252, isr253, isr254, isr255,
 };
 
-void (*list_of_handlers[256])(reg_t *);
+typedef int (*interrupt_handler)(reg_t *);
+
+interrupt_handler list_of_handlers[256];
 
 void int_handler(reg_t *r) {
-  list_of_handlers[r->int_no](r);
+  interrupt_handler handler = list_of_handlers[r->int_no];
+  if (NULL == handler) {
+    kprintf("[NOTE] Interrupt(0x%x) called but has no interrupt handler",
+            r->int_no);
+    return;
+  }
+
+  handler(r);
+
+  int is_kernel = (r->cs == 0x08);
+  if (!is_kernel) {
+    const signal_t *sig = process_pop_signal(NULL);
+    if (sig) {
+      process_push_restore_context(NULL, *r);
+      r->eip = sig->handler_ip;
+      kprintf("jumping to: %x\n", r->eip);
+      //      kprintf("esp: %x\n", r->esp);
+      //      kprintf("ebp: %x\n", r->ebp);
+
+      // Add magic value to the stack such that the signal handler
+      // returns to 0xDEADC0DE
+      r->useresp -= 4;
+      *(u32 *)r->useresp = 0xDEADC0DE;
+    }
+  }
 }
 
 void install_handler(void (*handler_function)(), u16 type_attribute, u8 entry) {
   format_descriptor((u32)isr_list[entry], KERNEL_CODE_SEGMENT_OFFSET,
                     type_attribute, &IDT_Entry[entry]);
-  list_of_handlers[entry] = handler_function;
+  list_of_handlers[entry] = (interrupt_handler)handler_function;
 }
 
 void idt_init(void) {
diff --git a/kernel/cpu/isr.s b/kernel/cpu/isr.s
new file mode 100644
index 0000000..1bb2fff
--- /dev/null
+++ b/kernel/cpu/isr.s
@@ -0,0 +1,297 @@
+.intel_syntax noprefix
+.section .text
+# Due to x86 not giving the interrupt number these isr stubs are
+# created. This is to allow a general isr stub for all interrupts. This
+# stub will act as a # multiplexer to the correct interrupt.
+.macro ISR_NOERRCODE num
+  .global isr\num
+  isr\num:
+    cli 
+    push 0
+    push \num
+    jmp isr_common_stub
+.endm
+
+ISR_NOERRCODE 0
+ISR_NOERRCODE 1
+ISR_NOERRCODE 2
+ISR_NOERRCODE 3
+ISR_NOERRCODE 4
+ISR_NOERRCODE 5
+ISR_NOERRCODE 6
+ISR_NOERRCODE 7
+ISR_NOERRCODE 8
+ISR_NOERRCODE 9
+ISR_NOERRCODE 10
+ISR_NOERRCODE 11
+ISR_NOERRCODE 12
+ISR_NOERRCODE 13
+ISR_NOERRCODE 14
+ISR_NOERRCODE 15
+ISR_NOERRCODE 16
+ISR_NOERRCODE 17
+ISR_NOERRCODE 18
+ISR_NOERRCODE 19
+ISR_NOERRCODE 20
+ISR_NOERRCODE 21
+ISR_NOERRCODE 22
+ISR_NOERRCODE 23
+ISR_NOERRCODE 24
+ISR_NOERRCODE 25
+ISR_NOERRCODE 26
+ISR_NOERRCODE 27
+ISR_NOERRCODE 28
+ISR_NOERRCODE 29
+ISR_NOERRCODE 30
+ISR_NOERRCODE 31
+ISR_NOERRCODE 32
+ISR_NOERRCODE 33
+ISR_NOERRCODE 34
+ISR_NOERRCODE 35
+ISR_NOERRCODE 36
+ISR_NOERRCODE 37
+ISR_NOERRCODE 38
+ISR_NOERRCODE 39
+ISR_NOERRCODE 40
+ISR_NOERRCODE 41
+ISR_NOERRCODE 42
+ISR_NOERRCODE 43
+ISR_NOERRCODE 44
+ISR_NOERRCODE 45
+ISR_NOERRCODE 46
+ISR_NOERRCODE 47
+ISR_NOERRCODE 48
+ISR_NOERRCODE 49
+ISR_NOERRCODE 50
+ISR_NOERRCODE 51
+ISR_NOERRCODE 52
+ISR_NOERRCODE 53
+ISR_NOERRCODE 54
+ISR_NOERRCODE 55
+ISR_NOERRCODE 56
+ISR_NOERRCODE 57
+ISR_NOERRCODE 58
+ISR_NOERRCODE 59
+ISR_NOERRCODE 60
+ISR_NOERRCODE 61
+ISR_NOERRCODE 62
+ISR_NOERRCODE 63
+ISR_NOERRCODE 64
+ISR_NOERRCODE 65
+ISR_NOERRCODE 66
+ISR_NOERRCODE 67
+ISR_NOERRCODE 68
+ISR_NOERRCODE 69
+ISR_NOERRCODE 70
+ISR_NOERRCODE 71
+ISR_NOERRCODE 72
+ISR_NOERRCODE 73
+ISR_NOERRCODE 74
+ISR_NOERRCODE 75
+ISR_NOERRCODE 76
+ISR_NOERRCODE 77
+ISR_NOERRCODE 78
+ISR_NOERRCODE 79
+ISR_NOERRCODE 80
+ISR_NOERRCODE 81
+ISR_NOERRCODE 82
+ISR_NOERRCODE 83
+ISR_NOERRCODE 84
+ISR_NOERRCODE 85
+ISR_NOERRCODE 86
+ISR_NOERRCODE 87
+ISR_NOERRCODE 88
+ISR_NOERRCODE 89
+ISR_NOERRCODE 90
+ISR_NOERRCODE 91
+ISR_NOERRCODE 92
+ISR_NOERRCODE 93
+ISR_NOERRCODE 94
+ISR_NOERRCODE 95
+ISR_NOERRCODE 96
+ISR_NOERRCODE 97
+ISR_NOERRCODE 98
+ISR_NOERRCODE 99
+ISR_NOERRCODE 100
+ISR_NOERRCODE 101
+ISR_NOERRCODE 102
+ISR_NOERRCODE 103
+ISR_NOERRCODE 104
+ISR_NOERRCODE 105
+ISR_NOERRCODE 106
+ISR_NOERRCODE 107
+ISR_NOERRCODE 108
+ISR_NOERRCODE 109
+ISR_NOERRCODE 110
+ISR_NOERRCODE 111
+ISR_NOERRCODE 112
+ISR_NOERRCODE 113
+ISR_NOERRCODE 114
+ISR_NOERRCODE 115
+ISR_NOERRCODE 116
+ISR_NOERRCODE 117
+ISR_NOERRCODE 118
+ISR_NOERRCODE 119
+ISR_NOERRCODE 120
+ISR_NOERRCODE 121
+ISR_NOERRCODE 122
+ISR_NOERRCODE 123
+ISR_NOERRCODE 124
+ISR_NOERRCODE 125
+ISR_NOERRCODE 126
+ISR_NOERRCODE 127
+ISR_NOERRCODE 128
+ISR_NOERRCODE 129
+ISR_NOERRCODE 130
+ISR_NOERRCODE 131
+ISR_NOERRCODE 132
+ISR_NOERRCODE 133
+ISR_NOERRCODE 134
+ISR_NOERRCODE 135
+ISR_NOERRCODE 136
+ISR_NOERRCODE 137
+ISR_NOERRCODE 138
+ISR_NOERRCODE 139
+ISR_NOERRCODE 140
+ISR_NOERRCODE 141
+ISR_NOERRCODE 142
+ISR_NOERRCODE 143
+ISR_NOERRCODE 144
+ISR_NOERRCODE 145
+ISR_NOERRCODE 146
+ISR_NOERRCODE 147
+ISR_NOERRCODE 148
+ISR_NOERRCODE 149
+ISR_NOERRCODE 150
+ISR_NOERRCODE 151
+ISR_NOERRCODE 152
+ISR_NOERRCODE 153
+ISR_NOERRCODE 154
+ISR_NOERRCODE 155
+ISR_NOERRCODE 156
+ISR_NOERRCODE 157
+ISR_NOERRCODE 158
+ISR_NOERRCODE 159
+ISR_NOERRCODE 160
+ISR_NOERRCODE 161
+ISR_NOERRCODE 162
+ISR_NOERRCODE 163
+ISR_NOERRCODE 164
+ISR_NOERRCODE 165
+ISR_NOERRCODE 166
+ISR_NOERRCODE 167
+ISR_NOERRCODE 168
+ISR_NOERRCODE 169
+ISR_NOERRCODE 170
+ISR_NOERRCODE 171
+ISR_NOERRCODE 172
+ISR_NOERRCODE 173
+ISR_NOERRCODE 174
+ISR_NOERRCODE 175
+ISR_NOERRCODE 176
+ISR_NOERRCODE 177
+ISR_NOERRCODE 178
+ISR_NOERRCODE 179
+ISR_NOERRCODE 180
+ISR_NOERRCODE 181
+ISR_NOERRCODE 182
+ISR_NOERRCODE 183
+ISR_NOERRCODE 184
+ISR_NOERRCODE 185
+ISR_NOERRCODE 186
+ISR_NOERRCODE 187
+ISR_NOERRCODE 188
+ISR_NOERRCODE 189
+ISR_NOERRCODE 190
+ISR_NOERRCODE 191
+ISR_NOERRCODE 192
+ISR_NOERRCODE 193
+ISR_NOERRCODE 194
+ISR_NOERRCODE 195
+ISR_NOERRCODE 196
+ISR_NOERRCODE 197
+ISR_NOERRCODE 198
+ISR_NOERRCODE 199
+ISR_NOERRCODE 200
+ISR_NOERRCODE 201
+ISR_NOERRCODE 202
+ISR_NOERRCODE 203
+ISR_NOERRCODE 204
+ISR_NOERRCODE 205
+ISR_NOERRCODE 206
+ISR_NOERRCODE 207
+ISR_NOERRCODE 208
+ISR_NOERRCODE 209
+ISR_NOERRCODE 210
+ISR_NOERRCODE 211
+ISR_NOERRCODE 212
+ISR_NOERRCODE 213
+ISR_NOERRCODE 214
+ISR_NOERRCODE 215
+ISR_NOERRCODE 216
+ISR_NOERRCODE 217
+ISR_NOERRCODE 218
+ISR_NOERRCODE 219
+ISR_NOERRCODE 220
+ISR_NOERRCODE 221
+ISR_NOERRCODE 222
+ISR_NOERRCODE 223
+ISR_NOERRCODE 224
+ISR_NOERRCODE 225
+ISR_NOERRCODE 226
+ISR_NOERRCODE 227
+ISR_NOERRCODE 228
+ISR_NOERRCODE 229
+ISR_NOERRCODE 230
+ISR_NOERRCODE 231
+ISR_NOERRCODE 232
+ISR_NOERRCODE 233
+ISR_NOERRCODE 234
+ISR_NOERRCODE 235
+ISR_NOERRCODE 236
+ISR_NOERRCODE 237
+ISR_NOERRCODE 238
+ISR_NOERRCODE 239
+ISR_NOERRCODE 240
+ISR_NOERRCODE 241
+ISR_NOERRCODE 242
+ISR_NOERRCODE 243
+ISR_NOERRCODE 244
+ISR_NOERRCODE 245
+ISR_NOERRCODE 246
+ISR_NOERRCODE 247
+ISR_NOERRCODE 248
+ISR_NOERRCODE 249
+ISR_NOERRCODE 250
+ISR_NOERRCODE 251
+ISR_NOERRCODE 252
+ISR_NOERRCODE 253
+ISR_NOERRCODE 254
+ISR_NOERRCODE 255
+
+isr_common_stub:
+    pusha                    # Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax
+
+    mov ax, ds               # Lower 16-bits of eax = ds.
+    push eax                 # save the data segment descriptor
+
+    mov ax, 0x10  # load the kernel data segment descriptor
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+
+    push esp
+    call int_handler
+    add esp, 4
+
+    pop ebx        # reload the original data segment descriptor
+    mov ds, bx
+    mov es, bx
+    mov fs, bx
+    mov gs, bx
+
+    popa                     # Pops edi,esi,ebp...
+    add esp, 8     # Cleans up the pushed error code and pushed ISR number
+    sti
+    iret           # pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP
diff --git a/kernel/drivers/keyboard.c b/kernel/drivers/keyboard.c
index f59e6a8..da04b1c 100644
--- a/kernel/drivers/keyboard.c
+++ b/kernel/drivers/keyboard.c
@@ -183,6 +183,7 @@ int keyboard_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
 }
 
 void add_keyboard(void) {
+  kprintf("very important");
   kb_inode = devfs_add_file("/keyboard", keyboard_read, NULL, NULL, 0, 0,
                             FS_TYPE_CHAR_DEVICE);
 }
diff --git a/kernel/drivers/rtl8139.c b/kernel/drivers/rtl8139.c
index 6e738db..b178078 100644
--- a/kernel/drivers/rtl8139.c
+++ b/kernel/drivers/rtl8139.c
@@ -105,6 +105,12 @@ void rtl8139_handler(void *regs) {
 }
 
 void rtl8139_send_data(u8 *data, u16 data_size) {
+  if (data_size > 0x1000) {
+    rtl8139_send_data(data, 0x1000);
+    data += 0x1000;
+    data_size -= 0x1000;
+    return rtl8139_send_data(data, data_size);
+  }
   kprintf("ipc_write\n");
   ipc_write(0, data, data_size);
   /*
diff --git a/kernel/ipc.c b/kernel/ipc.c
index 6367511..e29b169 100644
--- a/kernel/ipc.c
+++ b/kernel/ipc.c
@@ -47,10 +47,7 @@ int ipc_read(u8 *buffer, u32 length, u32 *sender_pid) {
   for (;;) {
     ipc_message = &handler->data[read_ptr];
     if (!ipc_message->is_used) {
-      return 0;
-//      kprintf("switch\n");
-//      switch_task();
-//      continue;
+       return 0;
     }
     kprintf("breaking out\n");
     break;
diff --git a/kernel/ipc.h b/kernel/ipc.h
index cfa9e6d..ae67f71 100644
--- a/kernel/ipc.h
+++ b/kernel/ipc.h
@@ -3,8 +3,8 @@
 #include <stdbool.h>
 #include <typedefs.h>
 
-#define IPC_BUFFER_SIZE 4096
-#define IPC_NUM_DATA 32
+#define IPC_BUFFER_SIZE 0x2000
+#define IPC_NUM_DATA 400
 
 struct IpcMessage {
   u8 is_used;
diff --git a/kernel/process.s b/kernel/process.s
index 9f8ee71..caef941 100644
--- a/kernel/process.s
+++ b/kernel/process.s
@@ -101,7 +101,7 @@ insert_eip_on_stack:
 # WARNING: Caller is expected to disable IRQs before calling, and enable IRQs again after function returns
 
 switch_to_task:
-	cli
+#	cli
  
     # Save previous task's state
  
diff --git a/kernel/sched/scheduler.c b/kernel/sched/scheduler.c
index 8019e5a..505dbd8 100644
--- a/kernel/sched/scheduler.c
+++ b/kernel/sched/scheduler.c
@@ -26,6 +26,66 @@ process_t *get_current_task(void) {
   return current_task;
 }
 
+void process_push_restore_context(process_t *p, reg_t r) {
+  if (!p) {
+    p = current_task;
+  }
+  reg_t *new_r = kmalloc(sizeof(reg_t));
+  memcpy(new_r, &r, sizeof(reg_t));
+  stack_push(&p->restore_context_stack, new_r);
+  return;
+}
+
+void process_pop_restore_context(process_t *p, reg_t *out_r) {
+  if (!p) {
+    p = current_task;
+  }
+  reg_t *r = stack_pop(&p->restore_context_stack);
+  if (NULL == r) {
+    assert(NULL);
+  }
+  memcpy(out_r, r, sizeof(reg_t));
+  kfree(r);
+}
+
+void process_push_signal(process_t *p, signal_t s) {
+  if (!p) {
+    p = current_task;
+  }
+
+  int index = -1;
+  for (int i = 0; i < 100; i++) {
+    const signal_t *s = p->active_signals[i];
+    if (!s) {
+      index = i;
+      break;
+    }
+  }
+  if (-1 == index) {
+    assert(0);
+    return;
+  }
+  signal_t *new_signal_entry = kmalloc(sizeof(signal_t));
+  memcpy(new_signal_entry, &s, sizeof(signal_t));
+  p->active_signals[index] = new_signal_entry;
+}
+
+const signal_t *process_pop_signal(process_t *p) {
+  if (!p) {
+    p = current_task;
+  }
+
+  for (int i = 0; i < 100; i++) {
+    const signal_t *s = p->active_signals[i];
+    if (!s) {
+      continue;
+    }
+    p->active_signals[i] = NULL;
+    return s;
+  }
+  return NULL;
+}
+
 bool get_task_from_pid(u32 pid, process_t **out) {
   for (process_t *tmp = ready_queue; tmp; tmp = tmp->next) {
     if (tmp->pid == pid) {
diff --git a/kernel/sched/scheduler.h b/kernel/sched/scheduler.h
index 01276dc..f73d8ef 100644
--- a/kernel/sched/scheduler.h
+++ b/kernel/sched/scheduler.h
@@ -4,6 +4,7 @@
 #include <fs/vfs.h>
 #include <halts.h>
 #include <ipc.h>
+#include <lib/stack.h>
 #include <mmu.h>
 #include <signal.h>
 #include <stdbool.h>
@@ -32,6 +33,10 @@ typedef struct {
   int fd;
 } MemoryMap;
 
+typedef struct {
+  uintptr_t handler_ip;
+} signal_t;
+
 typedef struct Process process_t;
 
 typedef struct TCB {
@@ -40,6 +45,11 @@ typedef struct TCB {
   uint32_t ESP0;
 } __attribute__((packed)) TCB;
 
+void process_push_restore_context(process_t *p, reg_t r);
+void process_pop_restore_context(process_t *p, reg_t *out_r);
+void process_push_signal(process_t *p, signal_t s);
+const signal_t *process_pop_signal(process_t *p);
+
 struct Process {
   u32 pid;
   char program_name[100];
@@ -57,6 +67,13 @@ struct Process {
   vfs_inode_t *read_halt_inode[100];
   vfs_inode_t *write_halt_inode[100];
   vfs_inode_t *disconnect_halt_inode[100];
+
+  //  // FIXME: Make this a array or circular buffer
+  //  reg_t restore_context;
+  struct stack restore_context_stack;
+
+  signal_t *active_signals[100];
+
   u32 halts[2];
   struct Halt *halt_list;
   void *data_segment_end;
diff --git a/kernel/syscalls/install_irq.c b/kernel/syscalls/install_irq.c
new file mode 100644
index 0000000..c50c6e0
--- /dev/null
+++ b/kernel/syscalls/install_irq.c
@@ -0,0 +1,26 @@
+#include <sched/scheduler.h>
+#include <syscalls.h>
+
+process_t *tmp;
+void *handler;
+
+void jump_signal_handler(void *func, u32 esp);
+
+void test_handler(reg_t *regs) {
+  kprintf("IRQ FIRED\n");
+  kprintf("handler: %x\n", handler);
+  tmp->interrupt_handler = handler;
+  signal_t sig;
+  sig.handler_ip = (uintptr_t)handler;
+  process_push_signal(tmp, sig);
+  return;
+}
+
+int syscall_install_irq(void (*irq_handler)(), u8 irq) {
+  // TODO: This should be able to fail if the handler is already set
+  tmp = get_current_task();
+  handler = irq_handler;
+  kprintf("IRQ INSTALLED\n");
+  install_handler(test_handler, INT_32_INTERRUPT_GATE(0x0), 0x20 + irq);
+  return 1;
+}
diff --git a/kernel/syscalls/map_frames.c b/kernel/syscalls/map_frames.c
new file mode 100644
index 0000000..1b0d097
--- /dev/null
+++ b/kernel/syscalls/map_frames.c
@@ -0,0 +1,6 @@
+#include <mmu.h>
+#include <syscalls.h>
+
+u32 syscall_map_frames(u32 address, u32 size) {
+  return (u32)mmu_map_user_frames((void *)address, size);
+}
diff --git a/kernel/syscalls/port.c b/kernel/syscalls/port.c
new file mode 100644
index 0000000..0a27a5e
--- /dev/null
+++ b/kernel/syscalls/port.c
@@ -0,0 +1,14 @@
+#include <syscalls.h>
+
+// FIXME: PERMISSION CHECKS
+void syscall_outw(u16 port, u16 word) {
+  outw(port, word);
+}
+
+void syscall_outl(u16 port, u32 l) {
+  outl(port, l);
+}
+
+u32 syscall_inl(u16 port) {
+  return inl(port);
+}
diff --git a/kernel/syscalls/virtual_to_physical.c b/kernel/syscalls/virtual_to_physical.c
new file mode 100644
index 0000000..e5b3eba
--- /dev/null
+++ b/kernel/syscalls/virtual_to_physical.c
@@ -0,0 +1,6 @@
+#include <mmu.h>
+#include <syscalls.h>
+
+u32 syscall_virtual_to_physical(u32 virtual) {
+  return (u32)virtual_to_physical((void *)virtual, NULL);
+}