6809: remove debug from lowlevel code, add more compiler glue

diff --git a/Kernel/lowlevel-6809.s b/Kernel/lowlevel-6809.s
index 6c7aa9c..466424f 100644 (file)
--- a/Kernel/lowlevel-6809.s
+++ b/Kernel/lowlevel-6809.s
@@ -13,7 +13,10 @@
        .globl  _udivhi3
        .globl  _umodhi3
        .globl  _mulhi3
-       .globl _swab
+       .globl  _ashlhi3
+       .globl  _lshrhi3
+       .globl  ___ashlsi3
+       .globl  _swab
 
        ; debugging aids
        .globl outcharhex
@@ -229,7 +232,6 @@ interrupt_handler:
 
            ; Do not use the stack before the switch...
 
-
             ; machine state stored by the cpu
            ; save zero page ??
             ldd _system_tick_counter
@@ -290,9 +292,6 @@ in_kernel:
            ;
            ; Y is caller saves so we'll get the right Y back
            ; for our SAM_RESTORE
-           inc 0x200
-;          lda 0xFF03
-;          lda 0xFF02
             jsr _platform_interrupt
 
             clr _inint
@@ -460,7 +459,7 @@ div0msg     .ascii  'Divby0'
        .db     13,10,0
 ;
 ;      Maths helpers - could be called from anywhere in C code
-;      From the GCC
+;      From the GCC support code (except for swab)
 ;
 _umodhi3:
        ldd     2,s
@@ -541,3 +540,55 @@ _swab:
        exg a,b         ; swap bytes over
        exg d,x         ; back into result
        rts
+
+_ashlhi3:
+       pshs    x
+_ashlhi3_1:
+       leax    -1,x
+       cmpx    #-1
+       beq     _ashlhi3_2
+       aslb
+       rola
+       bra     _ashlhi3_1
+_ashlhi3_2:
+       puls    x,pc
+
+___ashlsi3:
+       pshs    u
+       cmpb    #16
+       blt     try8
+       subb    #16
+       ; Shift by 16
+       ldu     2,x
+       stu     ,x
+try8:
+       cmpb    #8
+       blt     try_rest
+       subb    #8
+       ; Shift by 8
+
+try_rest:
+       tstb
+       beq     done
+do_rest:
+       ; Shift by 1
+       asl     3,x
+       rol     2,x
+       rol     1,x
+       rol     ,x
+       decb
+       bne     do_rest
+done:
+       puls    u,pc
+
+_lshrhi3:
+       pshs    x
+_lshrhi3_1:
+       leax    -1,x
+       cmpx    #-1
+       beq     _lshrhi3_2
+       lsra
+       rorb
+       bra     _lshrhi3_1
+_lshrhi3_2:
+       puls    x,pc