Assembler module for Flash

As mentioned in previous post, this post gives more information about loading an assembler based module.

var asm = require("ASM");
asm.setup(true);
asm.loadLibrary({
  varName:"Flash", fileName:"node_binaries/FLASH.BIN",
  functions:[
    {name:"read",format:"int(int)"},
    {name:"unlock",format:"void()"},
    {name:"write",format:"void(int,int)"},
    {name:"erase",format:"void(int)"},
    {name:"copyMem",format:"void(int,int,int)"},
    {name:"pageSafe",format:"int(int)"}
  ]
});

console.log(asm.listBinaries());

A binary file is loaded from fileName and creates an object named by varName.
This holds functions given by functions array.
Flash.read(adr) // returns an int-value from adr
Flash.unlock // unlocks flash memory, so you can change values
Flash.write(adr,value) // writes value to adr
Flash.erase(adr) // erases fullpage starting at adr
Flash.copyMem(source,destination,length) //copys from "length" bytes from source to destination
Flash.pageSafe(adr) // checks page for safe writing, returns 0 if safe

The assembly file holds a list of branches on top like this (see attached ASM file)

thumb;
;jump table for functions in this library
        b read          ;Flash.read(adr) adr is word aligned (word size 4 bytes)
        b unlock        ;Flash.unlock()
        b write         ;Flash.write(adr,val) adr is word aligned 
.....

An example, how this can be used is this:

console.log(asm.listBinaries());
console.log("pageSafe",Flash.pageSafe(adr));
console.log("read (0x0803E000):",Flash.read(adr).toString(16));
Flash.unlock();
console.log("unlocked");
Flash.write(adr,0xFFFFFFFE);
console.log("new value (-2) written");
console.log("read new value:",Flash.read(adr).toString(16));
Flash.copyMem(adr,adr+16,4);
console.log("copyMem done");
console.log("read target",Flash.read(adr+16).toString(16));
console.log("pageSafe, (should be <> 0):",Flash.pageSafe(adr).toString(16));
Flash.erase(adr);
console.log("erased");
console.log("pageSafe, should be 0:",Flash.pageSafe(adr).toString(16));

BTW, I had some experience with assembler many years ago. This is my first attempt in ARM assembler, any hint is welcome.

1 Attachment

• FLASH.ASM