fix Golden ram issues

codeCore/src/prog8/code/target/C64Target.kt

@@ -34,7 +34,7 @@ class C64Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by No
 
     override val BSSHIGHRAM_START = 0xc000u
     override val BSSHIGHRAM_END = 0xcfdfu
-    override val BSSGOLDENRAM_START = 0u
+    override val BSSGOLDENRAM_START = 0u        // no golden ram on C64
     override val BSSGOLDENRAM_END = 0u
 
     override lateinit var zeropage: Zeropage
@@ -80,7 +80,7 @@ class C64Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by No
 
     override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
         zeropage = C64Zeropage(compilerOptions)
-        golden = GoldenRam(compilerOptions, 0xc000u until 0xd000u)
+        golden = GoldenRam(compilerOptions, UIntRange.EMPTY)
     }
 
 }

codeCore/src/prog8/code/target/Cx16Target.kt

@@ -88,7 +88,7 @@ class Cx16Target: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by N
 
     override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
         zeropage = CX16Zeropage(compilerOptions)
-        golden = GoldenRam(compilerOptions, 0x0400u until 0x0800u)
+        golden = GoldenRam(compilerOptions, BSSGOLDENRAM_START..BSSGOLDENRAM_END)
     }
 
 

codeCore/src/prog8/code/target/PETTarget.kt

@@ -75,7 +75,7 @@ class PETTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by No
 
     override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
         zeropage = PETZeropage(compilerOptions)
-        // there's no golden ram.
+        golden = GoldenRam(compilerOptions, UIntRange.EMPTY)
     }
 
 }

codeCore/src/prog8/code/target/VMTarget.kt

@@ -84,6 +84,7 @@ class VMTarget: ICompilationTarget, IStringEncoding by Encoder, IMemSizer by Nor
 
     override fun initializeMemoryAreas(compilerOptions: CompilationOptions) {
         zeropage = VirtualZeropage(compilerOptions)
+        golden = GoldenRam(compilerOptions, UIntRange.EMPTY)
     }
 
     override fun memorySize(dt: DataType, numElements: Int?): Int {

compiler/src/prog8/CompilerMain.kt

@@ -131,20 +131,12 @@ private fun compileMain(args: Array<String>): Boolean {
     }
 
     if (varsGolden==true) {
-        if (compilationTarget != Cx16Target.NAME) {
-            System.err.println("Golden Ram is only available on the Commander X16 target.")
-            return false
-        }
         if (varsHighBank!=null || slabsHighBank!=null) {
             System.err.println("Either use varsgolden or varshigh (and slabsgolden or slabshigh), not both or mixed.")
             return false
         }
     }
     if (slabsGolden==true) {
-        if (compilationTarget != Cx16Target.NAME) {
-            System.err.println("Golden Ram is only available on the Commander X16 target.")
-            return false
-        }
         if (varsHighBank!=null || slabsHighBank!=null) {
             System.err.println("Either use golden or high ram, not both.")
             return false

compiler/src/prog8/compiler/Compiler.kt

@@ -71,6 +71,13 @@ fun compileProgram(args: CompilerArguments): CompilationResult? {
         getCompilationTargetByName(args.compilationTarget)
     }
 
+    if(args.varsGolden || args.slabsGolden) {
+        if(compTarget.BSSGOLDENRAM_END-compTarget.BSSGOLDENRAM_START==0u) {
+            System.err.println("The current compilation target doesn't support Golden Ram.")
+            return null
+        }
+    }
+
     try {
         val totalTime = measureTimeMillis {
             val libraryDirs =  if(compTarget.libraryPath!=null) listOf(compTarget.libraryPath.toString()) else emptyList()

compiler/src/prog8/compiler/astprocessing/AstChecker.kt

@@ -1053,6 +1053,8 @@ internal class AstChecker(private val program: Program,
                     err("invalid encoding directive, expected one of $allowedEncodings")
             }
             "%jmptable" -> {
+                if(directive.parent !is Block)
+                    err("this directive may only occur in a block")
                 for(arg in directive.args) {
                     val target = directive.definingScope.lookup(arg.string!!.split('.'))
                     if(target==null)

docs/source/compiling.rst

@@ -239,7 +239,7 @@ One or more .p8 module files
 ``-varsgolden``
     Like ``-varshigh``, but places the variables in the $0400-$07FF "golden ram" area instead.
     Because this is in normal system memory, there are no bank switching issues.
-    This mode is only available on the Commander X16.
+    This mode is only available on the Commander X16, and possibly on custom configured targets.
 
 ``-varshigh <rambank>``
     Places uninitialized non-zeropage variables in a separate memory area, instead of inside the program itself.

docs/source/programming.rst

@@ -374,6 +374,14 @@ Directives
         jmp  lib.routine2
         ...
 
+    This is usually put at the top of the main block so that it ends up at the beginning
+    of the library file. *Note:* the compiler may still insert the required bootstrapping
+    code in front of it, which in the case of a library, is the JMP to the start routine
+    which also does some variable initialization and BSS area clearing. So the first JMP
+    in the jumptable will then end up at offset 3 in the resulting binary. You could consider
+    the JMP start that prog8 inserts as the implicit first entry of the jump table.
+    Check the generated assembly code to see exactly what's up.
+
 .. data:: %launcher <type>
 
 	Level: module.