Only show one 'Loading' and one 'Verifying' progress bar when loading

[DavidEGrayson]

This makes the output much shorter and more useful when loading a UF2 file that writes to many different memory ranges, which can happen if it contains a filesystem. Also, this PR removes the "OK" message that was printed after verification: if the verification finished and there is no error message, that means everything was OK.

This is similar to what I did in my older pull request #66 from 18 months ago for picotool version 1, but that pull request had a bigger scope and was never merged in.

If you want to test this, here is a simple Ruby script I used to generate a fragmented UF2 file for a Pico 2:

#!/usr/bin/env ruby
# coding: ASCII-8BIT

output_filename = ARGV.fetch(0)

UF2_FLAG_FAMILY_ID_PRESENT = 0x2000
RP2040_FAMILY_ID = 0xe48bff56
RP2350_ARM_S_FAMILY_ID = 0xe48bff59

FRAGMENT_COUNT = 32
FRAGMENT_SIZE = 4096

block_map = {}
FRAGMENT_COUNT.times do |i|
  (FRAGMENT_SIZE/256).times do |j|
    block_map[i * FRAGMENT_SIZE * 2 + j * 256] = "\xAA" * 256
  end
end

File.open(output_filename, 'wb') do |output|
  block_map.keys.sort.each_with_index do |offset, block_number|
    address = offset + 0x1000_0000
    block = block_map.fetch(offset)
    uf2_block = "UF2\n\x57\x51\x5D\x9E" +
      [UF2_FLAG_FAMILY_ID_PRESENT, address, block.size,
      block_number, block_map.size, RP2350_ARM_S_FAMILY_ID].pack('<LLLLLL') +
      block.ljust(476, "\x00") + "\x30\x6F\xB1\x0A"
    output.write uf2_block
  end
end

Picotool output before this pull request:

$ ./picotool.exe load -v ../fragment.uf2
Family ID 'rp2350-arm-s' can be downloaded in absolute space:
  00000000->02000000
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Loading into Flash: [==============================]  100%
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK
Verifying Flash:    [==============================]  100%
  OK

Picotool output after this pull request:

$ ./picotool.exe load -v ../fragment.uf2
Family ID 'rp2350-arm-s' can be downloaded in absolute space:
  00000000->02000000
Loading:   [==============================]  100%
Verifying: [==============================]  100%

[lurch]

It's probably worth keeping the // new scope for progress bar comment, oherwise it might look like the { on the second line is associated with the for on the previous line 😉
Or alternatively, as there's now not multiple progress bars, perhaps this additional scope is no longer necessary? 🤔

[will-v-pi]

I'm happy with the general idea of this change, but I would want to keep the "OK" printout after verifying for clarity, and keep the "Loading into xxx" printout to specify whether it's loading into flash or SRAM. Therefore it will still need to split the memory ranges into different memory types, with a separate loading bar for each memory type - possibly by having get_coalesced_ranges return a vector<vector<range>> with a separate vector<range> for each memory type?

These changes should also be made to the verify command and the verify section of the save command, as those have similar progress bars.