memtable.py

#! /usr/bin/env python3
from __future__ import annotations

import argparse
import os
import os.path
from collections import defaultdict

from prettytable import PrettyTable

FIRMWARE_BASE = "/sys/firmware/memmap"


def oread(mdir: str, entry: str) -> str:
    with open(f"{FIRMWARE_BASE}/{mdir}/{entry}", "rt") as fp:
        return fp.read().strip()

def pretty_size(s: int):
    if isinstance(s, str):
        s = int(s, 16)

    s = float(s)
    e = 0
    suffs = ('', 'k', 'M', 'G', 'T', 'P')
    while s > 1000:
        s = s / 1024
        e += 1

    return f"{s:.2f} {suffs[e]}B"


def main():

    table = PrettyTable()
    table.align = "l"
    table.field_names = ('Id', "Type", "Start", "End", "Size")
    by_name = defaultdict(int)

    entry_keys = os.listdir(FIRMWARE_BASE)
    entry_keys.sort(key=lambda x: int(x))

    for memt in entry_keys:
        mtype = oread(memt, "type")
        mstart = oread(memt, "start")
        mend = oread(memt, "end")
        try:
            size = int(mend, 16) - int(mstart, 16)
            by_name[mtype] += size
            psize = pretty_size(size)
        except (ValueError, IndexError) as e:
            print(f"Can't compute size: {e}")
            size = 0

        row = [int(memt), mtype, mstart, mend, psize]

        table.add_row(row)

    table.add_divider()
    for mtype, size in by_name.items():
        table.add_row(["", mtype, "", "", pretty_size(size)])

    print(table)


if __name__ == '__main__':
    main()