Additional corrections to state restore logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@466 42af7a65-404d-4744-a932-0658087f49c3

3 files changed, 15 insertions, 16 deletions

diff --git a/nuttx/TODO b/nuttx/TODO
index a38b5b3d0..33db2ed41 100644
--- a/nuttx/TODO
+++ b/nuttx/TODO
@@ -231,9 +231,9 @@ o Build system
   Priority:    Low
 
   Description: Dependencies do not work correctly under configs/<board>/src
-               (same as arch/<arch>/src/board) with SDCC.
+               (same as arch/<arch>/src/board).  Seems to be worse using SDCC.
   Status:      Open
-  Priority:    Medium
+  Priority:    Medium (maybe higher for z80 target)
 
 o Applications & Tests (examples/)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/nuttx/arch/z80/include/z80/irq.h b/nuttx/arch/z80/include/z80/irq.h
index dbf61fe3e..3bcaaed20 100644
--- a/nuttx/arch/z80/include/z80/irq.h
+++ b/nuttx/arch/z80/include/z80/irq.h
@@ -70,13 +70,13 @@
  */
 
 #define XCPT_I               (0) /* Offset 0: Saved I w/interrupt state in carry */
-#define XCPT_AF              (1) /* Offset 1: Saved AF register */
-#define XCPT_BC              (2) /* Offset 2: Saved BC register */
-#define XCPT_DE              (3) /* Offset 3: Saved DE register */
-#define XCPT_HL              (4) /* Offset 4: Saved HL register */
-#define XCPT_IX              (5) /* Offset 5: Saved IX register */
-#define XCPT_IY              (6) /* Offset 6: Saved IY register */
-#define XCPT_SP              (7) /* Offset 7: Offset to SP at time of interrupt */
+#define XCPT_BC              (1) /* Offset 1: Saved BC register */
+#define XCPT_DE              (2) /* Offset 2: Saved DE register */
+#define XCPT_IX              (3) /* Offset 3: Saved IX register */
+#define XCPT_IY              (4) /* Offset 4: Saved IY register */
+#define XCPT_SP              (5) /* Offset 5: Offset to SP at time of interrupt */
+#define XCPT_HL              (6) /* Offset 6: Saved HL register */
+#define XCPT_AF              (7) /* Offset 7: Saved AF register */
 #define XCPT_PC              (8) /* Offset 8: Offset to PC at time of interrupt */
 
 #define XCPTCONTEXT_REGS     (9)
diff --git a/nuttx/arch/z80/src/common/up_restoreusercontext.asm b/nuttx/arch/z80/src/common/up_restoreusercontext.asm
index b37b6a752..61a8855b4 100644
--- a/nuttx/arch/z80/src/common/up_restoreusercontext.asm
+++ b/nuttx/arch/z80/src/common/up_restoreusercontext.asm
@@ -49,7 +49,6 @@
 ; up_restoreusercontext

 ;**************************************************************************

 

-;        .area	_CODE	(ABS,OVR)

 _up_restoreusercontext:

 	; On entry, stack contains return address (not used), then address

 	; of the register save structure

@@ -79,9 +78,7 @@ _up_restoreusercontext:
 	pop	ix			; Offset 3: IX

 	pop	iy			; Offset 4: IY

 	exx				;   Use alternate BC/DE/HL

-	ld	hl, #-2			;   Offset of SP to account for ret addr on stack

-	pop	de			; Offset 5: HL' = Stack pointer after return

-	add	hl, de			;   HL = Stack pointer value before return

+	pop	hl			; Offset 5: HL' = Stack pointer after return

 	exx				;   Restore original BC/DE/HL

 	pop	hl			; Offset 6: HL

 	pop	af			; Offset 7: AF

@@ -89,7 +86,9 @@ _up_restoreusercontext:
 	; Restore the stack pointer

 

 	exx				; Use alternate BC/DE/HL

+	pop	de			; DE' = return address

 	ld	sp, hl			; Set SP = saved stack pointer value before return

+	push	de			; Save return address for ret instruction

 	exx				; Restore original BC/DE/HL

 

 	; Restore interrupt state

@@ -97,8 +96,8 @@ _up_restoreusercontext:
 	ex	af, af'			; Recover interrupt state

 	jr	nc, noinrestore		; No carry, IFF2=0, means disabled

 	ex	af, af'			; Restore AF (before enabling interrupts)

-	ei				; yes

-	ret

+	ei				; yes.. Enable interrupts

+	ret				; and return

 noinrestore:

 	ex	af, af'			; Restore AF

-	ret

+	ret				; Return with interrupts disabled