Modified assembly routines to use x86's advanced addressing modes.HEADmaster

3 files changed, 7 insertions, 19 deletions

diff --git a/kernel/asm.s b/kernel/asm.s
index 4e1e376..32153e4 100644
--- a/kernel/asm.s
+++ b/kernel/asm.s
@@ -70,8 +70,7 @@ set_tss:
   push ebx
   mov eax, [ebp+12]
   mov ebx, [ebp+8]
-  shl ebx, 3
-  add ebx, gdt+40
+  lea ebx, [ebx*8+gdt+40]
   mov [ebx+2], ax
   shr eax, 16
   mov [ebx+4], al
@@ -92,9 +91,7 @@ clear_tss:
   mov ebp, esp
   push ebx
   mov ebx, [ebp+8]
-  shl ebx, 3
-  add ebx, gdt+40
-  mov byte [ebx+5], 0
+  mov byte [ebx*8+gdt+40+5], 0
   pop ebx
   pop ebp
   ret
diff --git a/kernel/boot.s b/kernel/boot.s
index 4db2cf7..e844c5b 100644
--- a/kernel/boot.s
+++ b/kernel/boot.s
@@ -186,8 +186,7 @@ register_isr:
   push ebp
   mov ebp, esp
   mov edx, [ebp+8]
-  shl edx, 3
-  add edx, idt
+  lea edx, [edx*8+idt]
   mov eax, [ebp+16]
   mov [edx], ax
   shr eax, 16
@@ -206,8 +205,7 @@ register_trap:
   push ebp
   mov ebp, esp
   mov edx, [ebp+8]
-  shl edx, 3
-  add edx, idt
+  lea edx, [edx*8+idt]
   mov eax, [ebp+16]
   mov [edx], ax
   shr eax, 16
diff --git a/kernel/traps.s b/kernel/traps.s
index ca083dd..475495b 100644
--- a/kernel/traps.s
+++ b/kernel/traps.s
@@ -117,10 +117,7 @@ traps_init:
   mov ecx, 0
   mov edx, idt
 .loop:
-  mov eax, ecx
-  shl eax, 2
-  add eax, traps
-  mov eax, [eax]
+  mov eax, [ecx*4+traps]
   mov [edx], ax
   shr eax, 16
   mov [edx+6], ax
@@ -279,9 +276,7 @@ syscall_handler:
   push ecx
   push ebx
   and eax, 0xFF
-  shl eax, 2
-  add eax, call_table
-  call [eax]
+  call [eax*4+call_table]
   add esp, 12
   ; preserve the syscall's return value
   mov [esp+30], eax
@@ -326,9 +321,7 @@ check_signals:
   inc ecx
   mov ebx, ecx
   ; calculate offset to the handler function
-  shl ecx, 2
-  add ecx, eax
-  add ecx, ts_sig_handlers
+  lea ecx, [ecx*4+eax+ts_sig_handlers]
   cmp dword [ecx], 0
   jne .custom_handler
   ; call the default handler