Only xon/xoff serial consoles are working

[pawosm-arm]

This is somewhat annoying bug, eventually I've managed to get to the point where it kicks in.

If a serial device is not xon/xoff, a jump to _cost function is being done, but since it is not call, just a jump, linker somehow did not resolve it correctly and it jumps somewhere, but not where it supposed to. A small patch like this one helps to sort it out:

diff --git a/CPM3.0/src/BIOSKRNL.ASM b/CPM3.0/src/BIOSKRNL.ASM
index 81fab54..a61f22f 100644
--- a/CPM3.0/src/BIOSKRNL.ASM
+++ b/CPM3.0/src/BIOSKRNL.ASM
@@ -282,7 +282,7 @@ coster: ; check for output device ready, including optional
     LD      A,(HL) 
     AND     010H        ; mb_xonxoff
     POP     HL      ; recover console number in <HL>
-    JR      Z,_cost     ; not a xon device, go get output status direct
+    JR      Z,cost_direct   ; not a xon device, go get output status direct
     LD      DE,xofflist 
     ADD     HL,DE       ; make pointer to proper xon/xoff flag
     CALL    cist1       ; see if this keyboard has character
@@ -300,6 +300,9 @@ not_s:
     CALL    cost1       ; get the actual output status,
     AND     (HL)        ; and mask with ctl-Q/ctl-S flag
     RET         ; return this as the status
+cost_direct:
+    CALL    _cost
+    RET
 cist1:  ; get input status with <BC> and <HL> saved
     PUSH    BC 
     PUSH    HL

I wonder how often this idiom is used, may be a source of a few mysterious problems.