dump more registers on panic, print register names

boot1.s

@@ -218,6 +218,10 @@ main:
 
   mov eax, 0xa1b2c3d4
   mov ebx, 0x12345678
+  mov ecx, 0xdeadbeef
+  mov edx, 0xcafebabe
+  mov esi, 0xfeedface
+  mov edi, 0x66778899
   call panic_fancy
 
   call test_a20
@@ -237,61 +241,71 @@ main:
   hlt
 
 
-; Wrapper function around panic_fancy which provides default arguments.
-; Arguments: none
-; Does not return
-panic_default:
-  push bp
-  mov bp, sp
-  push word 0
-  push word 0
-  ; Spoof return address
-  push dword [bp]
-  jmp panic_fancy
-
-
 ; Print a panic message then terminate.
 ; Arguments:
-; - [sp - 2]: panic message segment
+; - [sp + 2]: panic message segment
 ; - [sp]:     panic message offset
 ; Does not return
 panic_fancy:
   push bp
   mov bp, sp
 
-  sub sp, 16 ; Buffer: bp - 16
-
-  push eax   ; bp - 20
-  push ebx   ; bp - 24
-  push ecx   ; bp - 28
-  push edx   ; bp - 32
-  push esi   ; bp - 36
-  push edi   ; bp - 40
+  ; Flags first so we don't cobber them when we sub (uwu)
+  pushfd     ; Temp flags: bp - 0x04
+  sub sp, 16 ; Buffer:     bp - 0x14
+  push eax   ; eax:        bp - 0x18
+  push ebx   ; ebx:        bp - 0x1c
+  push ecx   ; ecx:        bp - 0x20
+  push edx   ; edx:        bp - 0x24
+  push esi   ; esi:        bp - 0x28
+  push edi   ; edi:        bp - 0x2c
+  sub sp, 4  ; Flags:      bp - 0x30
+  mov eax, [bp - 0x04]
+  mov [bp - 0x30], eax
 
   mov word [GLOBALS + VGA_COL], 0x4f00
   call vga_clear
 
   mov ax, ss
   mov es, ax
+
+  xor bx, bx
+  mov di, VGA_WIDTH * 3
+.loop_dump_regs:
+  cmp bx, 7
+  jae .loop_dump_regs_done
+
+  mov ax, bx
+  shl ax, 1
+  mov si, table_reg_msgs
+  add si, ax
+  mov cx, [si]
+  mov ax, di
+  add ax, 1
+  mov dx, 6
+  call vga_print_raw
+
+  ; Format the current saved register value as hex
+  lea si, [bp - 0x18]
+  mov ax, bx
+  shl ax, 2
+  sub si, ax
+  mov ecx, ss:[si]
+  lea ax, [bp - 0x14]
+  call dump_reg
+
+  mov ax, di
+  add ax, 7
+  lea cx, [bp - 0x14]
+  mov dx, 8
+  call vga_print_raw
+  
+  inc bx
+  add di, VGA_WIDTH
+  jmp .loop_dump_regs
+  
+.loop_dump_regs_done:
   
-  lea ax, [bp - 16]
-  push ax
-  mov ecx, [bp - 20]
-  call dump_reg
-  pop cx
-  xor ax, ax
-  mov dx, 8
-  call vga_print_raw
-
-  lea ax, [bp - 16]
-  push ax
-  mov ecx, [bp - 24]
-  call dump_reg
-  pop cx
-  mov ax, VGA_WIDTH
-  mov dx, 8
-  call vga_print_raw
-
 .halt:
   hlt
   ; Handle non-maskable interrupts
@@ -583,6 +597,24 @@ msg_a20_enabled  db "a20 enabled", 0
 msg_a20_disabled db "a20 not enabled", 0
 msg_panic        db "panic!", 0
 
+msg_reg_eax   db "eax", 0
+msg_reg_ebx   db "ebx", 0
+msg_reg_ecx   db "ecx", 0
+msg_reg_edx   db "edx", 0
+msg_reg_esi   db "esi", 0
+msg_reg_edi   db "edi", 0
+msg_reg_flags db "flags", 0
+
+table_reg_msgs:
+  dw msg_reg_eax
+  dw msg_reg_ebx
+  dw msg_reg_ecx
+  dw msg_reg_edx
+  dw msg_reg_esi
+  dw msg_reg_edi
+  dw msg_reg_flags
+  dw 0
+
 boot1_magic dd BOOT1_MAGIC
 
 BOOT1_TOTAL_LEN     equ $ - $$