Hello, i just uploaded a new VM, i built tonight and new NativeBoost code. VM is built from latest SVN + VMMaker + NativeBoostPlugin sources, and now NativeBoost can use all latest additions to interpreterProxy function table, such as addGCRoot, stackPointer etc. And there's already a code which using that, named NBExternalTypeRegistry. It serves as a dictionary of name->object values, where you can register any object under given name and then use it in native code (during native code generation). This is analoguous to what SpecialObjectArray serving for, where you can put an object and then use that object in primitives through well-known index. But in contrast to SpecialObjectArray, a NBExternalTypeRegistry doesn't requires from you to use indexes. You can use just names! Also, it doesn't requires from you to statically assign or initialize the same set of name/value pairs at each image startup. All what you need is just register an object first: NBExternalTypeRegistry current at: #MyName put: #(10 12 13) and then, in your assembler, emit code to load it: NBExternalTypeRegistry current emitOopAt: #MyName generator: gen When your restarting a VM, it makes sure that this registry are initially clean. So, it is get refilled only when some new native methods is generated which are using registry to fetch some named object(s). The most often use of named objects is, of course, instantiating the objects of specific class, like: self typeRegistry emitFetchClass: objectClass generator: gen. proxy instantiateClass: asm EAX indexableSize: 0. Or, checking that argument is of correct type. Here, the method which generates a code to verify that argument class (held in oop) will be an objectClass: validateClassOf: oop generator: gen | asm class | asm := gen asm. class := gen reserveTemp. gen proxy fetchClassOf: oop. asm mov: asm EAX to: class. self typeRegistry emitFetchClass: objectClass generator: gen. asm cmp: asm EAX with: class; jne: gen failedLabel. gen releaseTemps: 1. -- Best regards, Igor Stasenko AKA sig.