interrupt, smp: fix GDT code/data segment order, fix GDT size

interrupt/init.c

@@ -5,6 +5,7 @@
 #include "../runtime/stdio.h"
 #include "../runtime/panic_assert.h"
 #include "testcode.h"
+#include "string.h"
 
 bool interrupt_Enabled;
 
@@ -28,7 +29,7 @@ SYSV_ABI void interrupt_MapHandler(void *handler, int interrupt) {
 */
 
 // defined in assembly
-SYSV_ABI void interrupt_MapHandler(void *handler, int interrupt);
+//SYSV_ABI void interrupt_MapHandler(void *handler, int interrupt);
 
 
 void interrupt_Init() {
@@ -40,21 +41,21 @@ void interrupt_Init() {
 	io_WriteConsoleASCII("interrupt_Init() calling\n");
 
 	// set the 2 dummy gdts
-	uint64_t *gdt = (uint64_t *)KERNEL_GDT_MAPPING;
+	uint64_t *gdt                     = (uint64_t *)KERNEL_GDT_MAPPING;
-	gdt[0]        = 0;
+	gdt[0]                            = 0;
-	gdt[1]        = GDT_EXEC;
+	gdt[GDT_DATA_SELECTOR >> 3]       = GDT_DATA;
-	gdt[2]        = GDT_DATA;
+	gdt[GDT_EXEC_SELECTOR >> 3]       = GDT_EXEC;
-	gdt[3]        = GDT_EXEC_RING3;
+	gdt[GDT_DATA_RING3_SELECTOR >> 3] = GDT_DATA_RING3;
-	gdt[4]        = GDT_DATA_RING3;
+	gdt[GDT_EXEC_RING3_SELECTOR >> 3] = GDT_EXEC_RING3;
 	io_WriteConsoleASCII("GDT Installed\n");
 
-	interrupt_LoadGDT(4 * GDT_SIZE_BYTES - 1, (void *)KERNEL_GDT_MAPPING); // set it!
+	interrupt_LoadGDT(5 * GDT_SIZE_BYTES - 1, (void *)KERNEL_GDT_MAPPING); // set it!
 	io_WriteConsoleASCII("GDT OK\n");
 
 	//interrupt_Testcode();
 	io_WriteConsoleASCII("Testcode OK\n");
 
-
+	memset((void *)KERNEL_IDT_MAPPING, 0, KERNEL_IDT_SIZE);
 	interrupt_MapHandler(interrupt_Int0, 0);
 	interrupt_MapHandler(interrupt_Int1, 1);
 	interrupt_MapHandler(interrupt_Int2, 2);

interrupt/interrupt.h

@@ -8,16 +8,16 @@ extern "C" {
 #endif
 
 
-#define GDT_SIZE_BYTES 4
+#define GDT_SIZE_BYTES 8
 #define GDT_EXEC       0x00AF9A000000FFFFull // Base=0, Limit=max, Access=Present|Ring0|TypeUser|Exec|Readable, Flag=GranularityPage|Long
 #define GDT_DATA       0x00EF92000000FFFFull // Base=0, Limit=max, Access=Present|Ring0|TypeUser|Writable, Flag=GranularityPage|Size
 #define GDT_EXEC_RING3 0x00AFFA000000FFFFull // Base=0, Limit=max, Access=Present|Ring3|TypeUser|Exec|Readable, Flag=GranularityPage|Long
 #define GDT_DATA_RING3 0x00EFF2000000FFFFull // Base=0, Limit=max, Access=Present|Ring3|TypeUser|Writable, Flag=GranularityPage|Size
 
-#define GDT_EXEC_SELECTOR       0x08 // SelectorIndex=1, TableIndicator=GDT(0), Privilege=Ring0
+#define GDT_DATA_SELECTOR       0x08 // SelectorIndex=1, TableIndicator=GDT(0), Privilege=Ring0
-#define GDT_DATA_SELECTOR       0x10 // SelectorIndex=2, TableIndicator=GDT(0), Privilege=Ring0
+#define GDT_EXEC_SELECTOR       0x10 // SelectorIndex=2, TableIndicator=GDT(0), Privilege=Ring0
-#define GDT_EXEC_RING3_SELECTOR 0x1B // SelectorIndex=3, TableIndicator=GDT(0), Privilege=Ring3
+#define GDT_DATA_RING3_SELECTOR 0x1B // SelectorIndex=3, TableIndicator=GDT(0), Privilege=Ring3
-#define GDT_DATA_RING3_SELECTOR 0x23 // SelectorIndex=4, TableIndicator=GDT(0), Privilege=Ring3
+#define GDT_EXEC_RING3_SELECTOR 0x23 // SelectorIndex=4, TableIndicator=GDT(0), Privilege=Ring3
 
 #define IDT_PRESENT (1ull << 47)
 #define IDT_RING0   0

interrupt/interrupt_testcode.S

@@ -46,12 +46,18 @@ interrupt_Testcode:
 	lidt [idtr]
 	mov rax, int_handler
 	mov [idt+49*16], ax
-	mov word [idt+49*16+2], 0x08
+	mov word [idt+49*16+2], 0x10
 	mov word [idt+49*16+4], 0x8e00
 	shr rax, 16
 	mov [idt+49*16+6], ax
 	shr rax, 16
 	mov [idt+49*16+8], rax
 
+	; load the CS segment reg with 0x10
+	lea  rax, [.realint]
+	push qword 0x10
+	push rax
+	retfq
+.realint:
 	int 49
 	ret

interrupt/load_gdt.S

@@ -11,19 +11,18 @@ section '.text' executable
 ;
 ; Clobbers: rax
 interrupt_ReloadSegments:
-	;mov eax, 0x10  ; my data segment
+	mov ax, 0x08  ; my data segment
-	xor ax, ax
 	mov ds, ax
 	mov es, ax
 	mov fs, ax
 	mov gs, ax
 	mov ss, ax
 
-	;jmp  0x08:.flush
+	;jmp  0x10:.flush
 	; as in https://forum.osdev.org/viewtopic.php?f=1&t=30739
 	; farjump does not work in long mode, you need to do a far return:
 	pop  rax
-	push qword 0x08  ; my code segment
+	push qword 0x10  ; my code segment
 	push rax
 	retfq
 

interrupt/map_handler.S

@@ -16,7 +16,7 @@ interrupt_MapHandler:
 	shl rsi, 4                   ; rsi *= 16
 	add rsi, rax                 ; rsi += KERNEL_IDT_MAPPING
 	mov [rsi], di
-	mov word [rsi+2], 0x08       ; GDT_EXEC_SELECTOR (index=1)
+	mov word [rsi+2], 0x10       ; GDT_EXEC_SELECTOR (index=2)
 	mov word [rsi+4], 0x8e00
 	shr rdi, 16
 	mov [rsi+6], di

smp/kthread.c

@@ -72,7 +72,7 @@ smp_thread_ID smp_thread_Start(void *entry, const smp_thread_Arguments *args, un
 	t->waitCondition   = NULL;
 
 	t->state.cs  = GDT_EXEC_SELECTOR;
-	t->state.ss  = 0;
+	t->state.ss  = GDT_DATA_SELECTOR;
 	t->state.rip = (uint64_t)__smp_thread_EntryPoint;
 
 	t->state.rax = (uint64_t)entry;