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| -rw-r--r-- | todo.org | 30 |
1 files changed, 30 insertions, 0 deletions
@@ -17,6 +17,36 @@ Proposed syntax: #+begin_src asm init <label> #+end_src +* TODO Standard library +I should start considering this and how a user may use it. Should it +be an option in the VM and/or assembler binaries (i.e. a flag) or +something the user has to specify in their source files? + +Something to consider is /static/ and /dynamic/ "linking" i.e.: ++ Static linking: assembler inserts all used library definitions into + the bytecode output directly + + We could insert all of it at the start of the bytecode file, and + with [[*Start points][Start points]] this won't interfere with + user code + + Furthermore library code will have fixed program addresses (always + at the start) so we'll know at start of assembler runtime where to + resolve standard library subroutine calls + + Virtual machine needs no changes to do this ++ Virtual machine has fixed program storage for library code, and + assembler makes jump references specifically for this program + storage (dynamic linking) + + When assembling subroutine calls, just need to put references to + this library storage (some kind of shared state between VM and + assembler to know what these references are) + + VM needs to manage a ROM of some kind for library code + + How do we ensure assembled links to subroutine calls don't + conflict with user code jumps? + + Possibility: most significant bit of a program address is + reserved such that if 0 it refers to user code and if 1 it + refers to library code + + 63 bit references user code (not a lot of loss in precision) + + Easy to check if a reference is a library reference or a user + code reference by checking "sign bit" (negativity) * Completed ** DONE Write a label/jump system :ASM: Essentially a user should be able to write arbitrary labels (maybe |