Update

bootstrap.md

@@ -19,7 +19,7 @@ Bootstrapping has to start with some initial prerequisite machine dependent bina
 
 1. **Make a [simple](kiss.md) [programming language](programming_language.md) L**. You can choose e.g. the mentioned [Forth](forth.md) but you can even make your own, just remember to keep it extremely simple -- simplicity of the base language is the key feature here. If you also need a more complex language, write it in L. The language L will serve as tool for writing software for your platform, i.e. it will provide some comfort in programming (so that you don't have to write in assembly) but mainly it will be an **[abstraction](abstraction.md) layer** for the programs, it will allow them to run on any hardware/platform. The language therefore has to be **[portable](portability.md)**; it should probably abstracts things like [endianness](byte_sex.md), native integer size, control structures etc., so as to work nicely on all [CPUs](cpu.md), but it also mustn't have too much abstraction (such as [OOP](oop.md)) otherwise it will quickly get complicated. The language can compile e.g. to some kind of very simple [bytecode](bytecode.md) that will be easy to translate to any [assembly](assembly.md). Make the bytecode very simple (and document it well) as its complexity will later on determine the complexity of the bootstrap binary seed. At first you'll have to temporarily implement L in some already existing language, e.g. [C](c.md). NOTE: in theory you could just make bytecode, without making L, and just write your software in that bytecode, but the bytecode has to focus on being simple to translate, i.e. it will probably have few opcodes for example, which will be in conflict with making it at least somewhat comfortable to program on your platform. However one can try to make some compromise and it will save the complexity of translating language to bytecode, so it can be considered ([uxn](uxn.md) seems to be doing this).
 2. **Write L in itself, i.e. [self host](self_hosting.md) it**. This means you'll use L to write a [compiler](compiler.md) of L that outputs L's bytecode. Once you do this, you have a completely independent language and can start using it instead of the original compiler of L written in another language. Now compile L with itself -- you'll get the bytecode of L compiler. At this point you can bootstrap L on any platform as long as you can execute the L bytecode on it -- this is why it was crucial to make L and its bytecode very simple. In theory it's enough to just interpret the bytecode but it's better to translate it to the platform's native machine code so that you get maximum efficiency (the nature of bytecode should make it so that it isn't really more diffiult to translate it than to interpret it). If for example you want to bootstrap on an [x86](x86.md) CPU, you'll have to write a program (L compiler [backend](backend.md)) that translates the bytecode to x86 assembly; if we suppose that at the time of bootstrapping you will only have this x86 computer, you will have to write the translator in x86 assembly manually. If your bytecode really is simple and well made, it shouldn't be hard though (you will mostly be replacing your bytecode opcodes with given platform's machine code opcodes). Once you have the x86 backend, you can completely bootstrap L's compiler on any x86 computer.
-3. **Further help make L bootstrapable**. This means making it even easier to execute the L bytecode on any given platform -- you may for example write backends (the bytecode translators) for common platforms like x86, ARM, RISC-V, C, Lisp and so on. At this point you have L bootstrappable without any [work](work.md) on the platforms for which you provide backends and on others it will just take a tiny bit of work to write its own translator.
+3. **Further help make L bootstrapable**. This means making it even easier to execute the L bytecode on any given platform -- you may for example write backends (the bytecode translators) for common platforms like x86, ARM, RISC-V, C, Lisp and so on. You can also provide tests that will help check newly written backends for correctness. At this point you have L bootstrappable without any [work](work.md) on the platforms for which you provide backends and on others it will just take a tiny bit of work to write its own translator.
 4. **Write everything else in L**. This means writing the platform itself and software such as various tools and libraries. You can potentially even use L to write a higher level language (e.g. C) for yet more comfort in programming. Since everything here is written in L and L can be bootstrapped, everything here can be bootstrapped as well.
 
 ## Booting: Computer Starting Up