fix GPAW mask in the reset vector

dingelish · dingelish · commit 0877d44c9892 · 2024-09-09T17:32:52.000-07:00
GPAW is the [0:6] bit of ESP. the current mask 0x2f does not extract the 5th bit. 0x3f is the correct bitmask. this should close issue #734 Signed-off-by: Yu Ding <dingelish@gmail.com>
diff --git a/td-shim/ResetVector/Ia32/Flat32ToFlat64.asm b/td-shim/ResetVector/Ia32/Flat32ToFlat64.asm
@@ -22,7 +22,7 @@ Transition32FlatTo64Flat:
     ; LA57 and use 5-level paging
     ;
     mov     ecx, esp
-    and     ecx, 0x2f
+    and     ecx, 0x3f
     cmp     ecx, 52
     jl      .set_cr4
     bts     eax, 12

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,7 @@ Transition32FlatTo64Flat:`
`22`	`22`	`; LA57 and use 5-level paging`
`23`	`23`	`;`
`24`	`24`	`mov ecx, esp`
`25`		`- and ecx, 0x2f`
	`25`	`+ and ecx, 0x3f`
`26`	`26`	`cmp ecx, 52`
`27`	`27`	`jl .set_cr4`
`28`	`28`	`bts eax, 12`