entering the idle task appears to work

6 files changed, 48 insertions, 4 deletions

diff --git a/kc/core/Makefile b/kc/core/Makefile
index 2b8ab8d..7458ba5 100644
--- a/kc/core/Makefile
+++ b/kc/core/Makefile
@@ -12,7 +12,7 @@ CFLAGS += -Wno-unused-const-variable -Wno-unused-function -fvisibility=hidden -g
 SOBJS := 
 GOBJS := entry_x86_64.o reloc_x86_64.o kprint.o serial.o port.o \
 	 kc_main.o main.o memory.o memset.o memcpy.o memmove.o memcmp.o cpu.o \
-	 vm_tree.o exceptions.o panic.o msr.o 
+	 vm_tree.o exceptions.o panic.o msr.o task.o cpu_task.o 
 IOBJS :=
 
 # __attribute__((interrupt)) requires -mgeneral-regs-only
diff --git a/kc/core/exceptions.S b/kc/core/exceptions.S
index 46b9947..0a5b760 100644
--- a/kc/core/exceptions.S
+++ b/kc/core/exceptions.S
@@ -26,6 +26,7 @@
 
 .macro ISR_RESTORE_REGISTERS
     // restore all the registers
+    pop %r15
     pop %r14
     pop %r13
     pop %r12
@@ -57,7 +58,7 @@
 page_fault_isr:
     ISR_STORE_REGISTERS
     /* collect parameters for page fault handler */
-    mov 48(%rsp), %rdi /* error code is first parameter */
+    mov 120(%rsp), %rdi /* error code is first parameter */
     mov %cr2, %rsi /* PFLA is next parameter */
     /* stack has to be aligned */
     ISR_CALL page_fault_handler
diff --git a/kc/core/kc_main.c b/kc/core/kc_main.c
index 1eb07da..68fcb0a 100644
--- a/kc/core/kc_main.c
+++ b/kc/core/kc_main.c
@@ -3,6 +3,7 @@
 #include "kprint.h"
 #include "memory.h"
 #include "panic.h"
+#include "task.h"
 
 #include <kernel/entry.h>
 
@@ -19,6 +20,8 @@ unsigned long kc_main(struct kc_boot_data *data)
     serial_init();
     kputs("<hacker voice> i'm in 3333\r\n");
     memory_init(data);
-    halt();
+    task_init();
+
+    return 0;
 }
 
diff --git a/kc/core/memory.c b/kc/core/memory.c
index 9956bfd..ba0ca57 100644
--- a/kc/core/memory.c
+++ b/kc/core/memory.c
@@ -537,12 +537,12 @@ static uint64_t *get_kernel_pm2e(void *vaddr)
     return &kernel_pm2[kpm2_index(vaddr)];
 }
 
-
 int anonymous_page_handler(uint32_t code, void *address)
 {
     kputs("anonymous space fault\n");
     if (code & PAGE_PR)
     {
+        kputs("can't fault a present page\n");
         // there's no reason a protection violation should happen
         // in anonymous space
         panic(UNHANDLED_FAULT);
diff --git a/kc/core/task.c b/kc/core/task.c
index 8f78516..b825f01 100644
--- a/kc/core/task.c
+++ b/kc/core/task.c
@@ -2,6 +2,7 @@
 #include "memory.h"
 #include "panic.h"
 #include "cpu.h"
+#include "kprint.h"
 
 struct kc_thread *current_task = NULL;
 struct kc_thread *first_ready_task = NULL;
@@ -72,5 +73,42 @@ static void set_thread_status(enum kc_thread_status status)
 
 static void idle_task_thread(void)
 {
+    kputs("in idle thread\n");
+    while (1)
+    {
+        __asm__ volatile ("hlt;");
+    }
+    kputs("scheduling\n");
+    lock_scheduler();
+    task_schedule();
+    unlock_scheduler();
+}
+
+noreturn void task_init(void)
+{
+    char *kernel_rsp0 = vm_alloc(4096);
+    // TODO: make it so this isn't demand-allocated.
+    kernel_rsp0[1] = 0;
+    *get_tss_rsp0() = (uintptr_t)kernel_rsp0;
+    char *first_task = vm_alloc(16384);
+    struct kc_thread *idle_thread =
+        (struct kc_thread *)(first_task + 16384 - sizeof(*idle_thread));
+    idle_thread->state.stack = (uintptr_t)idle_thread;
+    idle_thread->state.stack_top = (uintptr_t)kernel_rsp0;
+    
+    __asm__ volatile
+        (
+         "mov %%cr3, %%rax\n\t"
+         "mov %%rax, 0(%%rsi)\n\t"
+         "mov %%rcx, %%rsp\n\t"
+         "jmp idle_task_thread\n\t"
+         : "=m"(idle_thread->state.page_map)
+         : "S"(&idle_thread->state.page_map),
+         "c"(idle_thread)
+         : "rax"
+        );
+
+    // shouldn't ever get here
+    panic(GENERAL_PANIC);
 }
 
diff --git a/kc/core/task.h b/kc/core/task.h
index 86e262f..e9ddaaf 100644
--- a/kc/core/task.h
+++ b/kc/core/task.h
@@ -31,3 +31,5 @@ extern void cpu_set_thread(
         struct kc_thread_state *next,
         uint64_t *cpu_tss_rsp0);
 
+void task_init(void);
+