dragon-nx32: Cruft removal and some cosmetics in tricks.s

We don't need to preserve Y because it is properly stacked.

Signed-off-by: Tormod Volden <debian.tormod@gmail.com>

diff --git a/Kernel/platform-dragon-nx32/tricks.s b/Kernel/platform-dragon-nx32/tricks.s
index 49bcd50..d678285 100644 (file)
--- a/Kernel/platform-dragon-nx32/tricks.s
+++ b/Kernel/platform-dragon-nx32/tricks.s
@@ -21,12 +21,12 @@
         .globl _dofork
        .globl _ramtop
 
-
         include "kernel.def"
         include "../kernel09.def"
 
        .area .common
 
+       ; ramtop must be in common although not used here
 _ramtop:
        .dw 0
 
@@ -55,7 +55,6 @@ _switchout:
 
        ; Stash the uarea into process memory bank
        jsr map_process_always
-       sty _swapstack+2
 
        ldx #U_DATA
        ldy #U_DATA_STASH
@@ -63,37 +62,32 @@ stash       ldd ,x++
        std ,y++
        cmpx #U_DATA+U_DATA__TOTALSIZE
        bne stash
-       ldy _swapstack+2
 
        ; get process table in
        jsr map_kernel
 
-        ; find another process to run (may select this one again) returns it
-        ; in X
+        ; find another (or same) process to run, returned in X
         jsr _getproc
         jsr _switchin
         ; we should never get here
         jsr _trap_monitor
 
-_swapstack .dw 0
-       .dw 0
-
 badswitchmsg: .ascii "_switchin: FAIL"
             .db 13
            .db 10
            .db 0
 
+newpp   .dw 0
+
 ; new process pointer is in X
 _switchin:
         orcc #0x10             ; irq off
 
-       ;pshs x
-       stx _swapstack
-       ; get process table - must be in already from switchout
-       ; jsr map_kernel
+       stx newpp
+       ; get process table
        lda P_TAB__P_PAGE_OFFSET+1,x            ; LSB of 16-bit page no
 
-       ; if we are switching to the same process
+       ; check if we are switching to the same process
        cmpa U_DATA__U_PAGE+1
        beq nostash
 
@@ -101,21 +95,19 @@ _switchin:
        cmpa #0
        bne not_swapped
        jsr _swapper            ; void swapper(ptptr p)
-       ldx _swapstack
+       ldx newpp
        lda P_TAB__P_PAGE_OFFSET+1,x
 
 not_swapped:
        jsr map_process_a
        
        ; fetch uarea from process memory
-       sty _swapstack+2
        ldx #U_DATA_STASH
        ldy #U_DATA
 stashb ldd ,x++
        std ,y++
        cmpx #U_DATA_STASH+U_DATA__TOTALSIZE
        bne stashb
-       ldy _swapstack+2
 
        ; we have now new stacks so get new stack pointer before any jsr
        lds U_DATA__U_SP
@@ -124,8 +116,7 @@ stashb      ldd ,x++
        jsr map_kernel
 
 nostash:
-       ;puls x
-       ldx _swapstack
+       ldx newpp
         ; check u_data->u_ptab matches what we wanted
        cmpx U_DATA__U_PTAB
         bne switchinfail
@@ -160,6 +151,7 @@ switchinfail:
         jmp _trap_monitor
 
        .area .data
+
 fork_proc_ptr: .dw 0 ; (C type is struct p_tab *) -- address of child process p_tab entry
 
        .area .common
@@ -221,9 +213,9 @@ fork_copy:
        lda U_DATA__U_PAGE+1            ; old bank
        ldx #0x8000                     ; PROGBASE
        ldu U_DATA__U_TOP
-       jsr copybank            ; preserves A,B, clobbers X,U
+       jsr copybank                    ; preserves A,B, clobbers X,U
 
-; stash parent urea (including kernel stack)
+; stash parent uarea (including kernel stack)
        jsr map_process_a
        ldx #U_DATA
        ldu #U_DATA_STASH