ENTRY_ARG_VGA handle_10
iretw
+#define VGA_CUSTOM_BDA_FLAGS 0xb9
+#define BF_EXTRA_STACK 0x40
+
// Entry point using extra stack
DECLFUNC entry_10_extrastack
entry_10_extrastack:
cli
cld
- pushw %ds // Set %ds:%eax to space on ExtraStack
+ pushw %ds
pushl %eax
- movw %cs:ExtraStackSeg, %ds
+
+ movw $SEG_BDA, %ax // Check if extra stack is enabled
+ movw %ax, %ds
+ testb $BF_EXTRA_STACK, VGA_CUSTOM_BDA_FLAGS
+ jz 1f
+
+ movw %cs:ExtraStackSeg, %ds // Set %ds:%eax to space on ExtraStack
movl $(CONFIG_VGA_EXTRA_STACK_SIZE-PUSHBREGS_size-16), %eax
SAVEBREGS_POP_DSEAX // Save registers on extra stack
movl %esp, PUSHBREGS_size+8(%eax)
RESTOREBREGS_DSEAX
iretw
+1: // Use regular entry point if the extra stack is disabled
+ popl %eax
+ popw %ds
+ jmp entry_10
+
// Timer irq handling
DECLFUNC entry_timer_hook
entry_timer_hook: