Scheduling + setting up files

src/kernel/arch_i386/idt.s

@@ -352,3 +352,19 @@ _irq_common_stub:
     popad
     add esp, 8
     iret
+
+global panic_hold
+
+panic_hold:
+    
+    push ebp
+    mov ebp, esp
+    
+    mov esp, [ebp + 8]
+    
+    pop gs
+    pop fs
+    pop es
+    pop ds
+    popad
+    jmp $

src/kernel/arch_i386/interrupts.c

@@ -41,17 +41,16 @@ void _irq_handler(cpu_registers_t *regs){
     }
     else if(interrupt_handlers[regs->int_no - 32])
     {
-        if(regs->int_no == 32){
+        // printf("found one for an int");
-            // printf("Tick\n");
-            // printf("%x\n", regs->int_no);
-        }
         regs = interrupt_handlers[regs->int_no - 32](regs);
+        // printf("returned;")
         // printf("eip: %x", regs->eip);
-        outb(0x20, 0x20);
-        if(regs->int_no >= 0x28){
-            outb(0xa0, 0x20);
-        }
     }
+    outb(0x20, 0x20);
+    if(regs->int_no >= 0x28){
+        outb(0xa0, 0x20);
+    }
+    return;
 }
 void _isr_handler(cpu_registers_t *regs){
     printf("Error!! %x\n", regs->eip);
@@ -62,6 +61,16 @@ cpu_registers_t *syscall(cpu_registers_t *regs){
     
 }
 
+extern void panic_hold(cpu_registers_t *regs);
+
+void kernel_panic(char *message, cpu_registers_t *regs){
+    printf("Kernel Panic!\nAn fatal error occured, and could not be recovered.\nError: ");
+    printf(message);
+    printf("System halting...\n");
+    if(regs != 0) panic_hold(regs);
+    asm volatile ("jmp .");
+}
+
 void install_irq_handler(void (*handler)(), uint8_t irqno){
     interrupt_handlers[irqno] = handler;
 }
@@ -74,7 +83,7 @@ void init_idt(){
     // printf("last ")
     for(uint32_t i = 0; i < 16; i++){
         set_idt_entry(i + 32, (_irq0 + ((_irq1 - _irq0) * i)), IDT_GATE_INT, 0x10);
-        printf("int %d: address: %x\n", i + 32, _irq0 + (_irq1 - _irq0) * i);
+        // printf("int %d: address: %x\n", i + 32, _irq0 + (_irq1 - _irq0) * i);
     }
     
     idt_desc.pointer = (uint32_t)&idt_table;

src/kernel/arch_i386/memory.c

@@ -4,11 +4,11 @@
 
 #define mmap_count 0x20000
 
-uint8_t pm_map[mmap_count];
+uint8_t volatile pm_map[mmap_count];
 
 uint32_t total_memory = 0;
 uint32_t total_memory_usable = 0;
-uint32_t last_allocated = 0;
+uint32_t volatile last_allocated = 0;
 extern uint32_t _start;
 
 uint32_t pm_alloc(){

src/kernel/kmain.c

@@ -4,6 +4,7 @@
 #include "shared/interrupts.h"
 #include "drivers/serial.h"
 #include "drivers/pic.h"
+#include "system/scheduler.h"
 
 extern void kmain(kernel_info_t *kernel_info){
     init_serial();
@@ -11,9 +12,10 @@ extern void kmain(kernel_info_t *kernel_info){
     init_idt();
     init_pic(32);
     pic_disable();
+    init_scheduler();
     pic_setmask(0xfe, PIC1_DATA);
     enable_interrupts();
-    printf("done\n");
+    // printf("done\n");
     for(;;);
     return;
 }

src/kernel/shared/interrupts.h

@@ -29,4 +29,5 @@ inline void enable_interrupts(){
 inline void disable_interrupts(){
     asm volatile("cli");
 }
+void kernel_panic(char *msg, cpu_registers_t *regs);
 void install_irq_handler(void (*handler)(), uint8_t irqno);

src/kernel/shared/kstdlib.h

@@ -1,6 +1,8 @@
 #pragma once
 // #include "memory.h"
 #include "../drivers/serial.h"
+#include "interrupts.h"
+
 typedef struct kernel_info{
     void *mmap_ptr;
     uint16_t mmap_entry_count;
@@ -12,3 +14,5 @@ typedef struct kernel_info{
     void *loaded_modues;
     uint32_t loaded_module_count;
 }__attribute__((packed)) kernel_info_t;
+
+#define PANIC(m) kernel_panic(m, 0)

src/kernel/shared/memory.h

@@ -67,5 +67,12 @@ uint32_t get_paddr(void *addr);
 uint32_t pm_alloc();
 void pm_reserve(uint32_t addr);
 void pm_free(uint32_t addr);
-
+inline void set_cr3(void *cr3){
+    asm volatile("mov %0, %%eax; mov %%eax, %%cr3":: "r"(cr3));
+}
+inline void *get_cr3(){
+    void *cr3;
+    asm volatile("mov %%cr3, %%eax;mov %0, %%eax": "=r"(cr3));
+    return cr3;
+}
 int pm_init(kernel_info_t *kernel_info);

src/kernel/system/devices.h

@@ -0,0 +1,33 @@
+#include<stdint.h>
+
+typedef struct{
+    uint32_t devid;
+    enum DeviceType{
+        NULL_TYPE,
+        DEV_TYPE_DISK,
+        DEV_TYPE_AUDIO,
+        DEV_TYPE_KBD,
+        DEV_TYPE_MOUSE,
+        DEV_TYPE_VIDEO,
+        DEV_TYPE_OTHER,
+        DEV_TYPE_NAT,
+    }device_type;
+    uint32_t driver_pid;
+}device_t;
+typedef struct{
+    uint64_t start_sector; //Register or sector (depending on command and or device type)
+    uint64_t total_sectors;//hard disks only
+    volatile void *buffer;
+    uint32_t buffer_size;//size of each object in buffer
+    uint32_t buffer_count;//Number of objects of size buffer_size in buffer
+    enum DeviceCommand{
+        NULLOP,
+        DEVICE_READ,
+        DEVICE_WRITE,
+        DEVICE_INIT,
+        DEVICE_COMMAND,
+        DEVICE_SET_MMAP,
+        DEVICE_SET_DMA,
+    }command;
+    uint32_t requesting_pid;
+}device_packet_t;

src/kernel/system/modules.c

@@ -0,0 +1,2 @@
+#include "modules.h"
+

src/kernel/system/modules.h

@@ -0,0 +1,2 @@
+#pragma once
+#include <stdint.h>

src/kernel/system/scheduler.c

@@ -0,0 +1,69 @@
+#include "../shared/interrupts.h"
+#include "scheduler.h"
+#include "../shared/kstdlib.h"
+
+process_t volatile processes[0x10000];
+uint32_t volatile process_queue[0x10000];
+uint32_t volatile current_pid;
+
+void init_scheduler(){
+    for(uint32_t i = 0; i < 0x10000; i++){
+        processes[i].flags.present = 0;
+        process_queue[i] = 0;
+    }
+    current_pid = 0;
+    install_irq_handler(schedule, 0);
+    printf("Installing scheduler");
+}
+
+cpu_registers_t *schedule(cpu_registers_t *regs){
+    uint32_t i = current_pid;
+    // printf("Test");
+    while(processes[process_queue[i]].flags.blocked){
+        i++;
+        if(i == current_pid) return regs;
+        if(i >= 0x10000) i = 0;
+    }
+    current_pid = i;
+    return &(processes[i].cpuregs);
+    // return regs;
+}
+
+void spawn_new_process(cpu_registers_t defaultregs, char **argv, uint32_t argc, void *cr3){
+    uint32_t i = current_pid;
+    while(processes[i].flags.present){
+        i++;
+        if(i >= 0x10000) i = 0;
+        if(i == current_pid) return;
+    }
+    process_t new_proc = {0};
+    new_proc.argc = argc;
+    new_proc.argv = argv;
+    new_proc.page_dir = cr3;
+    new_proc.cpuregs = defaultregs;
+    new_proc.parent = current_pid;
+    new_proc.flags.present = 1;
+    new_proc.flags.cpu_lvl = 1;
+    new_proc.flags.priority = 0;
+    new_proc.flags.system = processes[current_pid].flags.system;
+    return;
+}
+
+void fork(){
+    
+}
+void exec(){
+    
+}
+void exit(){
+    
+}
+void thread_start(void (*function)(), uint32_t *exit_code){
+    
+}
+void thread_join(uint32_t thread_id, uint32_t **exit_code){
+    
+}
+void thread_exit(uint32_t *exit_code){
+    
+}

src/kernel/system/scheduler.h

@@ -0,0 +1,24 @@
+#pragma once
+#include <stdint.h>
+#include "../shared/interrupts.h"
+typedef struct{
+    char **argv;
+    uint32_t argc;
+    cpu_registers_t cpuregs;
+    void *page_dir;
+    struct pflags{
+        uint8_t blocked :1;
+        uint8_t system  :1;
+        uint8_t cpu_lvl :1;
+        uint8_t priority:3;
+        uint8_t present :1;
+        uint8_t unused  :1;
+    }flags;
+    uint32_t thread_id;
+    uint32_t parent;
+    uint32_t uid;
+    uint32_t gid;
+}process_t;
+
+cpu_registers_t* schedule(cpu_registers_t *regs);
+void init_scheduler();