Implement proper string/file execution routines and argc/argv handlin…

…g, make all processes their own threads but "halt" the caller

bos.inc

@@ -496,6 +496,11 @@ namespace bos
 ?util_RemoveFromSymList          := $226C8
 ?util_SearchSymList              := $226CC
 ?util_FreeSymList                := $226D0
+?sys_Exec                        := $226D4
+?sys_ExecV                       := $226D8
+?sys_ExecData                    := $226DC
+?sys_ExecBegin                   := $226E0
+?sys_ExecContinue                := $226E4
 ; end of jump table
 ;-------------------------------------------------------------------------------
 ; OS memory areas and misc defines
@@ -549,6 +554,7 @@ namespace bos
 ?saved_LcdUpbase        := ti.appData+60 ; 3 bytes, saves LcdUpbase during sector caching
 ?text_flags             := ti.appData+63 ; 1 byte. Instructs the OS character printing routines
 ?gfx_routine_temp       := ti.appData+64 ; 16 bytes, temp location for graphics routines
+?LastExitCode           := ti.appData+80 ; 4 bytes, stores the exit code of the last program that finished executing
 ?ScrapByte              := ti.flashByte
 ?ScrapWord              := ti.scrapMem
 ?ScrapMem               := ti.scrapMem

bos.src

@@ -178,6 +178,11 @@
 	public _util_RemoveFromSymList
 	public _util_SearchSymList
 	public _util_FreeSymList
+	public _sys_Exec
+	public _sys_ExecV
+	public _sys_ExecData
+	public _sys_ExecBegin
+	public _sys_ExecContinue
 _boot_os                         := $20108
 _handle_interrupt                := $2010C
 _HandleInstruction               := $20110
@@ -356,6 +361,11 @@ _util_AppendSymList              := $226C4
 _util_RemoveFromSymList          := $226C8
 _util_SearchSymList              := $226CC
 _util_FreeSymList                := $226D0
+_sys_Exec                        := $226D4
+_sys_ExecV                       := $226D8
+_sys_ExecData                    := $226DC
+_sys_ExecBegin                   := $226E0
+_sys_ExecContinue                := $226E4
 
 public ram_executable
 public ram_executable_at

src/compatibility/_Str.asm

@@ -21,12 +21,12 @@ _StrCmpre:
 _StrLength:
 	push af,hl
 	xor a,a
-	sbc hl,hl
 	ld c,a
 	mlt bc
 	cpir
+	scf
+	sbc hl,hl
 	sbc hl,bc
-	dec hl
 	ex (sp),hl
 	pop bc,af
 	ret