Initial SMP support. Intializes AP and it halts in realmode. Fixed ou…

…tputting last character in a line. Aligned user mode stack in 8 bytes boundary. Fixed protected mode address loading in boot loader.

apic.c

@@ -78,7 +78,7 @@ void init_lapic() {
  print_msg("Local APIC id", lapic_id, 16, true);
 
  // enable receiving interrupt
- //write_lapic_register(LAPIC_SPURIOUS_REG, read_lapic_register(LAPIC_SPURIOUS_REG)| 0x100);
+ write_lapic_register(LAPIC_SPURIOUS_REG, read_lapic_register(LAPIC_SPURIOUS_REG)| 0x100);
 }
 
 void lapic_switch(bool enable) {

apic.h

@@ -21,21 +21,23 @@
 #define LAPIC_PPR 0xa0
 #define LAPIC_EOI_REG 0xb0
 #define LAPIC_SPURIOUS_REG 0xf0
-#define ISR_0_31 0x100
-#define TMR_0_31 0x180
-#define IRR_0_31 0x200
-#define ERROR_STATUS_REG 0x280
-#define ICR_1 0x300
-#define ICR_2 0x310
-#define LVT_TIMER_REG 0x320
-#define LVT_LINT_0_REG 0x350
-#define LVT_LINT_1_REG 0x360
-#define LVT_ERROR_REG 0x370
-#define INITIAL_COUNTER_REG 0x380
-#define CURRENT_COUNTER_REG 0x390
-#define DIVIDE_CONFIGURATION_REG 0x3e0
+#define LAPIC_ISR_0_31 0x100
+#define LAPIC_TMR_0_31 0x180
+#define LAPIC_IRR_0_31 0x200
+#define LAPIC_ERROR_STATUS_REG 0x280
+#define LAPIC_ICR_1 0x300
+#define LAPIC_ICR_2 0x310
+#define LAPIC_LVT_TIMER_REG 0x320
+#define LAPIC_LVT_LINT_0_REG 0x350
+#define LAPIC_LVT_LINT_1_REG 0x360
+#define LAPIC_LVT_ERROR_REG 0x370
+#define LAPIC_INITIAL_COUNTER_REG 0x380
+#define LAPIC_CURRENT_COUNTER_REG 0x390
+#define LAPIC_DIVIDE_CONFIGURATION_REG 0x3e0
 
 void init_lapic();
 void lapic_switch(bool enable);
+int read_lapic_register(int lapic_register);
+void write_lapic_register(int lapic_register, int value);
 
 #endif

bootldr.S

@@ -18,7 +18,6 @@
  .equ E820_MAP_ADDR, 0x1008
  .equ PROTECTED_MODE_STACK, 0xf000
  .equ KERNEL_SECTORS, ((KERNEL_SIZE + 0x200 -1) / 0x200)
- .equ PIT_FREQUENCY, 1000
 
  // machine boots in 16bit real mode
  .code16
@@ -206,7 +205,7 @@ protectedmodeaddress:
  movl %eax, %gs
 
  // initialize protected mode stack
- movl PROTECTED_MODE_STACK, %eax
+ movl $PROTECTED_MODE_STACK, %eax
  movl %eax, %esp
  movl %eax, %ebp
 

handlr32.S

@@ -48,8 +48,6 @@
  push %es
  push %fs
  push %gs
-
- movl %esp, %ebp
 
  movl $0x28, %eax 
  movl %eax, %ds
@@ -59,6 +57,7 @@
 
  sti
 
+ movl %esp, %ebp
  push %ebp
  call common_interrupt_handler
  addl $4, %esp
@@ -146,6 +145,7 @@
 
 
 common_trap_handler:
+ cli
  pusha
 
  push %ds
@@ -171,6 +171,7 @@ common_trap_handler:
  pop %ds
 
  popa
+ sti
 
  iret
 

kernel32.ld

@@ -12,6 +12,9 @@ SECTIONS
  . = ALIGN(4096);
  .um : AT(ADDR(.um) - 0x80000000) {*(.um);}
  um_size = SIZEOF(um);
+ . = ALIGN(4096);
+ .mp_init : AT(ADDR(.mp_init) - 0x80000000) {*(.mp_init);}
+ mp_init_size = SIZEOF(mp_init);
  .kernel_data ALIGN(4096) : AT(ADDR(.kernel_data) - 0x80000000) {*(.kernel_data); }
  . = ALIGN(4096);
  _kernel_pg_dir = .;

mpinit.S

@@ -0,0 +1,31 @@
+/*****************************************************************************/
+/* File: mp_init.S */
+/* */
+/* Description: Startup code for AP. */
+/* */
+/* Author: Shoily O Rahman <[email protected]> */
+/* */
+/* Date: Aug 9, 2020 */
+/* */
+/*****************************************************************************/
+
+ .equ AP_COUNT_PHYS_ADDR, 0xfff8
+ .code16
+
+ .globl init_ap
+
+ .section "mp_init", "ax"
+
+init_ap:
+
+ cli
+ xorw %ax, %ax
+ movw %ax, %ss
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %fs
+ movw %ax, %gs
+
+ incw AP_COUNT_PHYS_ADDR
+
+ hlt

setup32.c

@@ -14,6 +14,7 @@
 #include "system.h"
 #include "setup32.h"
 #include "apic.h"
+#include "smp.h"
 
 // GDT data
 struct gdt_entry __attribute__((aligned(8))) gdt[LAST_SEG/8];
@@ -68,41 +69,22 @@ void irq_handler_13();
 void irq_handler_14();
 void irq_handler_15();
 
+void lapic_irq_handler_0();
 void lapic_irq_handler_1();
 
-
 __attribute__((regparm(0))) void trap_handler(struct regs_frame *rf) {
 
- char str[20];
-
  print_vga("Trap handler", true);
 
- itoa(rf->gs, str, 16);
- print_vga(str, true);
-
- itoa(rf->fs, str, 16);
- print_vga(str, true);
-
- itoa(rf->es, str, 16);
- print_vga(str, true);
-
- itoa(rf->ds, str, 16);
- print_vga(str, true);
-
- itoa(rf->code_nr, str, 16);
- print_vga(str, true);
-
- itoa(rf->cs, str, 16);
- print_vga(str, true);
-
- itoa(rf->eip, str, 16);
- print_vga(str, true);
-
- itoa(rf->ss, str, 16);
- print_vga(str, true);
-
- itoa(rf->esp, str, 16);
- print_vga(str, true);
+ print_msg("gs", rf->gs, 16, false);
+ print_msg("fs", rf->fs, 16, false);
+ print_msg("es", rf->es, 16, false);
+ print_msg("ds", rf->ds, 16, false);
+ print_msg("code_nr", rf->code_nr, 16, false);
+ print_msg("cs", rf->cs, 16, false);
+ print_msg("eip", rf->eip, 16, false);
+ print_msg("ss", rf->ss, 16, false);
+ print_msg("esp", rf->esp, 16, false);
 
  __asm__ __volatile__("1: hlt; jmp 1b;" : : : );
 }
@@ -253,16 +235,16 @@ void setup32() {
  setupGDT32();
  setupLDT32();
 
- if (!lapic_present) {
- init_pic_8259();
- init_pit_frequency();
- }
-
  init_lapic();
 
+ init_pic_8259();
+ init_pit_frequency();
+
  setupIDT32();
  setupTSS32();
 
+ smp_start();
+
  STI;
 
  print_vga("Setup GDT,IDT, LDT and TSS done", true);

smp.c

@@ -0,0 +1,67 @@
+/*****************************************************************************/
+/* File: smp.c */
+/* */
+/* Description: Source file SMP related code. */
+/* */
+/* Author: Shoily O Rahman <[email protected]> */
+/* */
+/* Date: Aug 9, 2020 */
+/* */
+/*****************************************************************************/
+
+#include "util.h"
+#include "system.h"
+#include "apic.h"
+
+#define AP_INIT_PHYS_TEXT 0xf000
+#define AP_COUNT_PHYS_ADDR 0xfff8
+
+extern int mp_init_size;
+extern int init_ap;
+
+void copy_smp_init_to_low_mem() {
+
+ char *s = (char*)&init_ap;
+ char *d = (char*)(AP_INIT_PHYS_TEXT+KERNEL_VIRT_ADDR);
+
+ for(int i=0;i<(int)&mp_init_size;i++) {
+ *d++ = *s++;
+ }
+}
+
+void smp_start() {
+
+ int status;
+
+ copy_smp_init_to_low_mem();
+
+ // initialize AP processor count with 0
+ // it will be increased by AP startup code
+ *(int*)(AP_COUNT_PHYS_ADDR+KERNEL_VIRT_ADDR) = 0;
+
+ MFENCE;
+
+ // send INIT IPI to APs
+ write_lapic_register(LAPIC_ICR_1, 0x000c4500);
+ write_lapic_register(LAPIC_ICR_2, 0);
+ for(int i=0;i<10;i++) {
+ status = read_lapic_register(LAPIC_ICR_1) & 0x1000;
+ if (!status)
+ break;
+ pit_wait(0xffff);
+ }
+
+ // send Startup IPI to APs
+ write_lapic_register(LAPIC_ICR_1, 0x000c4600 | (AP_INIT_PHYS_TEXT >> 12));
+ write_lapic_register(LAPIC_ICR_2, 0);
+ for(int i=0;i<30;i++) {
+ status = read_lapic_register(LAPIC_ICR_1) & 0x1000;
+ if (!status)
+ break;
+ pit_wait(0xffff);
+ }
+
+ pit_wait(0xffff);
+
+ print_msg("Number of APs", *(int*)(AP_COUNT_PHYS_ADDR+KERNEL_VIRT_ADDR), 10, true);
+}

smp.h

@@ -0,0 +1,17 @@
+/*****************************************************************************/
+/* File: smp.h */
+/* */
+/* Description: Header file SMP related code. */
+/* */
+/* Author: Shoily O Rahman <[email protected]> */
+/* */
+/* Date: Aug 9, 2020 */
+/* */
+/*****************************************************************************/
+
+#ifndef SMP_H
+#define SMP_H
+
+void smp_start();
+
+#endif

system.c

@@ -10,6 +10,11 @@
 /* */
 /*****************************************************************************/
 
+//
+// Reserved memory aside from E820
+//
+// 
+
 #include "system.h"
 #include "util.h"
 
@@ -33,7 +38,7 @@ void print_vga(char *c, bool newline) {
  c++;
  vga_buffer_index += 2;
  p++;
- if (vga_buffer_index > 160) {
+ if (vga_buffer_index == 160) {
  vga_buffer_line++;
  vga_buffer_index = 0;
  }

usermode.c

@@ -19,7 +19,7 @@ char __attribute__((aligned(4096))) um_pg_table[4096];
 char __attribute__((aligned(4096))) user_mode_program[4096];
 
 #define USER_MODE_STACK_SIZE 8192
-char user_mode_stack[USER_MODE_STACK_SIZE];
+char __attribute__((aligned(8))) user_mode_stack[USER_MODE_STACK_SIZE];
 
 extern int um, um_size;
 extern int _kernel_pg_dir;
@@ -45,8 +45,6 @@ void load_usermode_function(char *usermodefunction) {
  for(i=(int)&um;i<(int)&um+(int)&um_size;i++) {
  *d++ = *s++;
  }
-
- print_vga("User mode progam copied", true);
 }
 
 void switch_to_um() {
@@ -89,6 +87,4 @@ void initialize_usermode() {
  MFENCE;
 
  switch_to_um();
-
- print_vga("Test", true);
 }