Move aseg-paging to netwatch/

[netwatch.git] / netwatch / entry.asm

diff --git a/netwatch/entry.asm b/netwatch/entry.asm
new file mode 100644 (file)
index 0000000..151382e
--- /dev/null
+++ b/netwatch/entry.asm
@@ -0,0 +1,52 @@
+       org 0xA8000
+[bits 16]
+entry:
+       mov ax, 0xA800                  ; Take us out of flat unreal mode,
+       mov ds, ax                      ; and put us in true real mode.
+       mov es, ax
+       mov fs, ax
+       mov gs, ax
+       mov ss, ax
+       jmp 0xA800:(entry2-0xA8000)     ; Long jump to a correct cs.
+entry2:
+       lgdt [(gdtr-0xA8000)]           ; Set up a new GDT.
+       mov eax, 0x1
+       mov cr0, eax                    ; ... and enter pmode!
+       jmp long 0x10:continue          ; Now longjmp into the new code.
+[bits 32]
+continue:
+       mov ax, 0x08                    ; Set up segment selectors.
+       mov ds, ax
+       mov es, ax
+       mov fs, ax
+       mov gs, ax
+       mov ss, ax
+       mov esp, [dataptr]              ; Load stack pointer.
+
+       ; Before we do anything, turn off alignment checking.
+       pushf
+       pop eax
+       and eax, ~(1 << 18)
+       push eax
+       popf
+       
+       mov eax, [dataptr+4]            ; Load target jump address
+       call eax                        ; then jump into C.
+
+       rsm                             ; and leave SMM
+
+       align 0x4
+gdtr:
+       db 0x17, 0x00
+       dd gdt
+       align 0x4
+gdt:
+       db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00       ; initial null entry
+       db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x93, 0xCF, 0x00       ; data segment
+       db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9B, 0xCF, 0x00       ; code segment
+
+
+dataptr:
+       ; 4 bytes of stack top
+       ; 4 bytes of C entry point
+       ; These show up