Instructions for patching firmware 4.1.7729

[GeoffR]

This firmware version has only been oficially released for the Aura One and Aura Edition 2, it should work on other Mk 6 devices (Glo HD) but don't try to install it on other devices unless you know what you are doing, installing the wrong firmware could potentailly result in an unbootable ereader.

See the Firmware 4.1.7729 discussion thread for information about what has changed in this firmware version.

See the Index to the Metazoa firmware patches thread for a description of what some of these patches do.


Before starting:

1. Make sure your Kobo ereader is already running firmware version 4.1.7729 (8bedc76ce7). If not, then you need to upgrade before applying this patch.

2. Check that your battery is well charged.


Patching from Windows, Linux (i386/x86_64), or Mac (OS X 10.8-10.9, i386/x86_64):

1. Download and extract patch_kobo_4017729.zip (attached).

2. Download the Kobo firmware archive version 4.1.7729 for your device (See this thread) and copy it into the 4.1.7729_source/ subdirectory. (Don't unzip the firmware.)

3. Read and edit all the *.patch files in the 4.1.7729_source/ subdirectory in order to: choose which patches to enable (patch_enable=`yes`) or disable (patch_enable=`no`); and to change some of the replacement values to suit your device and preferences.

4. In Windows double-click 4.1.7729.bat; For Linux/Mac open a terminal, change to the patch_kobo_4017729/ subdirectory, and run ./4.1.7729.sh from the command line.

5. If there were no errors, copy the resulting KoboRoot.tgz from the 4.1.7729_target/ subdirectory to the .kobo directory on your ereader.

6. Safely eject and unplug the device, which will then update and restart.


To return your ereader to its original unpatched state:

1. Edit all the 4.1.7729_source/*.patch files to disable all patches (set patch_enable = `no` for every patch).

2. Repeat steps 4-6 of the procedure above.


Note that the following patches are enabled by default:

`Fix page breaks bug`
`Default ePub monospace font (Courier)`
`Custom left & right margins`
`Search in Library by default`
`Custom page refresh options (1,2,3,...,12)`
`Fix three KePub fullScreenReading bugs`

[GeoffR]

The firmware link for this version (Mk6 devices only) is http://download.kobobooks.com/firmwa...e-4.1.7729.zip

The following patches are still missing:

Spoiler:

libadobe.so.patch:
`Remove PDF page turn arrows at left and right edges of page`

libnickel.so.1.0.0.patch:
`Custom page refresh options (1,8,32,Chapter -- Aura only)`
`Custom page refresh options (1,32,99,Chapter -- Aura only)`
`Remove system fonts in Reader list`
`Remove non-system fonts in Reader list`
`Customise PinchGestureRecognizer`
`Margins fine tuning`
`Change dicthtml strings to micthtml`

The `Custom Sleep/Power-off timeouts` patch has changed, it can now only change the highest timeout value on the menu.

The `ePub fixed/adjustable top/bottom margins` patch is now two separate patches: `ePub fixed top/bottom margins` and `ePub fixed/adjustable top/bottom margins`.

The following four patches created by oren64 are now included in nickel.patch:
`Changing the info panel in full size screensaver`
`Dictionary frame size`
`Increase The Books Cover Size In The Library`
`Increasing The View Details Container`

For the `My 24 line spacing values` patch, these alternative replacement values might better suit lower-dpi devices like the Aura 2ed:

Spoiler:

# 24 values for replacement, change these replace_float values to suit:
#
base_address = 5EAC10
replace_float = 0000, 1.0, 0.7
replace_float = 0008, 1.0, 0.725
replace_float = 0010, 1.0, 0.75
replace_float = 0018, 1.0, 0.775
replace_float = 0020, 1.0, 0.8
replace_float = 0028, 1.0, 0.825
replace_float = 0030, 1.0, 0.85
replace_float = 0038, 1.0, 0.875
replace_float = 0040, 1.0, 0.9
replace_float = 0048, 1.0, 0.925
replace_float = 0050, 1.0, 0.95
replace_float = 0058, 1.0, 0.975
replace_float = 0060, 1.0, 1.0
replace_float = 0068, 1.0, 1.025
base_address = 5EAD70
replace_float = 0000, 1.05, 1.05
replace_float = 0008, 1.07, 1.07
replace_float = 0010, 1.1, 1.1
replace_float = 0018, 1.35, 1.15
replace_float = 0020, 1.7, 1.2
replace_float = 0028, 1.8, 1.25
replace_float = 0030, 2.2, 1.3
replace_float = 0038, 2.4, 1.35
replace_float = 0040, 2.6, 1.4
replace_float = 0048, 2.8, 1.5

Other patches:

`Cyrillic keyboard` patch for Aura One, thanks AxaRu.

`Greek keyboard` patch for Aura One, thanks isaak.

Here is a `Keyboard template` patch (libnickel.so.1.0.0.patch) for the Aura One. (You'll need to fill in the replacement values with the keys you want according to the pattern in the comments.)

Spoiler:

<Patch>
patch_name = `Keyboard template (Aura One)`
patch_enable = `yes`
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad.
#
# Aura One keyboard layout:
#
# Row:  Position
# ---:-----------
# Top: 0123456789
# 2nd: 0123456789
# 3rd: 0123456789
# Bot:  12345678
#  
# Untested: Enable uppercase for `ß` key (Top row, pos 7)
#replace_bytes = 711920, 00 26, 01 26
#
# Replace layout sign (Cyrillic example)
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `абв`
# Change keyboard layout
find_base_address = `š\0ž\0þ\0ŀ\0`
# Top row, pos 2-3
replace_string = 0000, `š`, `2`
replace_string = 0003, `ž`, `3`
# Top row, pos 6
replace_string = 0006, `þ`, `6`
# Top row, pos 9
replace_string = 0009, `ŀ`, `9`
#
find_base_address = `æ\0à\0è\0ì\0`
# Top row, pos 0-1
replace_string = 0021, `ý`, `0`
replace_string = 0045, `ÿ`, `1`
# Top row, pos 4-5
replace_string = 0000, `æ`, `4`
replace_string = 0024, `œ`, `5`
# Top row, pos 7-8
replace_string = 0054, `ß`, `7`
replace_string = 0060, `ij`, `8`
# Second row, left to right:
replace_string = 0003, `à`, `0`
replace_string = 0012, `á`, `1`
replace_string = 0027, `â`, `2`
replace_string = 0036, `ä`, `3`
replace_string = 0048, `ã`, `4`
replace_string = 0051, `å`, `5`
replace_string = 0006, `è`, `6`
replace_string = 0015, `é`, `7`
replace_string = 002A, `ê`, `8`
replace_string = 0039, `ë`, `9`
# Third row, left to right:
replace_string = 000C, `ò`, `0`
replace_string = 001B, `ó`, `1`
replace_string = 0030, `ô`, `2`
replace_string = 003F, `ö`, `3`
replace_string = 004E, `õ`, `4`
replace_string = 005D, `ø`, `5`
replace_string = 0009, `ì`, `6`
replace_string = 0018, `í`, `7`
replace_string = 002D, `î`, `8`
replace_string = 003C, `ï`, `9`
# Bottom row, left to right:
replace_string = 000F, `ù`, `1`
replace_string = 001E, `ú`, `2`
replace_string = 0033, `û`, `3`
replace_string = 0042, `ü`, `4`
replace_string = 004B, `ñ`, `5`
replace_string = 0057, `ç`, `6`
replace_string = 005A, `đ`, `7`
replace_string = 0063, `ł`, `8`
</Patch>

Here are keyboard patches for other devices (libnickel.so.1.0.0.patch):

Spoiler:

<Patch>
patch_name = `Cyrillic keyboard`
patch_enable = `no`
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Cyrillic alternatives.
#  
# Enable uppercase for `ß` key
replace_bytes = 711920, 00 26, 01 26
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `абв`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `й`
replace_string = 0003, `à`, `ц`
replace_string = 0006, `è`, `у`
replace_string = 0009, `ì`, `к`
replace_string = 000C, `ò`, `е`
replace_string = 000F, `ù`, `н`
replace_string = 0012, `á`, `г`
replace_string = 0015, `é`, `ш`
replace_string = 0018, `í`, `щ`
replace_string = 001B, `ó`, `з`
replace_string = 001E, `ú`, `х`
replace_string = 0021, `ý`, `ъ`
# Third row, left to right:
replace_string = 0024, `œ`, `ф`
replace_string = 0027, `â`, `ы`
replace_string = 002A, `ê`, `в`
replace_string = 002D, `î`, `а`
replace_string = 0030, `ô`, `п`
replace_string = 0033, `û`, `р`
replace_string = 0036, `ä`, `о`
replace_string = 0039, `ë`, `л`
replace_string = 003C, `ï`, `д`
replace_string = 003F, `ö`, `ж`
replace_string = 0042, `ü`, `э`
replace_string = 0045, `ÿ`, `ё`
# Bottom row, left to right:
replace_string = 0048, `ã`, `я`
replace_string = 004B, `ñ`, `ч`
replace_string = 004E, `õ`, `с`
replace_string = 0051, `å`, `м`
replace_string = 0054, `ß`, `и`
replace_string = 0057, `ç`, `т`
replace_string = 005A, `đ`, `ь`
replace_string = 005D, `ø`, `б`
replace_string = 0060, `ij`, `ю`
replace_string = 0063, `ł`, `.`
</Patch>


<Patch>
patch_name = `Arabic keyboard`
patch_enable = `no`
# Multi-version patch: 4.0.7523 - 4.1.7729+
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Arabic alternatives.
## Note that after the device boots, the keypad will just show blank squares
## until the first book has been opened.
#  
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `ع`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `ذ`
replace_string = 0003, `à`, `ص`
replace_string = 0006, `è`, `ث`
replace_string = 0009, `ì`, `ق`
replace_string = 000C, `ò`, `ف`
replace_string = 000F, `ù`, `غ`
replace_string = 0012, `á`, `ع`
replace_string = 0015, `é`, `ه`
replace_string = 0018, `í`, `خ`
replace_string = 001B, `ó`, `ح`
replace_string = 001E, `ú`, `ج`
replace_string = 0021, `ý`, `د`
# Third row, left to right:
replace_string = 0024, `œ`, `ض`
replace_string = 0027, `â`, `ش`
replace_string = 002A, `ê`, `س`
replace_string = 002D, `î`, `ي`
replace_string = 0030, `ô`, `ب`
replace_string = 0033, `û`, `ل`
replace_string = 0036, `ä`, `ا`
replace_string = 0039, `ë`, `ت`
replace_string = 003C, `ï`, `ن`
replace_string = 003F, `ö`, `م`
replace_string = 0042, `ü`, `ك`
replace_string = 0045, `ÿ`, `ط`
# Bottom row, left to right:
replace_string = 0048, `ã`, `ئ`
replace_string = 004B, `ñ`, `ء`
replace_string = 004E, `õ`, `ؤ`
replace_string = 0051, `å`, `ر`
replace_string = 0054, `ß`, `ى`
replace_string = 0057, `ç`, `ة`
replace_string = 005A, `đ`, `و`
replace_string = 005D, `ø`, `ز`
replace_string = 0060, `ij`, `ظ`
replace_string = 0063, `ł`, `.`
</Patch>


<Patch>
patch_name = `Hebrew keyboard`
patch_enable = `no`
# Multi-version patch: 4.0.7523 - 4.1.7729+
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Hebrew alternatives.
## Note that after the device boots, the keypad will just show blank squares
## until the first book has been opened.
#
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `אב`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `@`
replace_string = 0003, `à`, `'`
replace_string = 0006, `è`, `/`
replace_string = 0009, `ì`, `ק`
replace_string = 000C, `ò`, `ר`
replace_string = 000F, `ù`, `א`
replace_string = 0012, `á`, `ט`
replace_string = 0015, `é`, `ו`
replace_string = 0018, `í`, `ן`
replace_string = 001B, `ó`, `ם`
replace_string = 001E, `ú`, `פ`
replace_string = 0021, `ý`, `-`
# Third row, left to right:
replace_string = 0024, `œ`, `,`
replace_string = 0027, `â`, `ש`
replace_string = 002A, `ê`, `ד`
replace_string = 002D, `î`, `ג`
replace_string = 0030, `ô`, `כ`
replace_string = 0033, `û`, `ע`
replace_string = 0036, `ä`, `י`
replace_string = 0039, `ë`, `ח`
replace_string = 003C, `ï`, `ל`
replace_string = 003F, `ö`, `ך`
replace_string = 0042, `ü`, `ף`
replace_string = 0045, `ÿ`, `_`
# Bottom row, left to right:
replace_string = 0048, `ã`, `ז`
replace_string = 004B, `ñ`, `ס`
replace_string = 004E, `õ`, `ב`
replace_string = 0051, `å`, `ה`
replace_string = 0054, `ß`, `נ`
replace_string = 0057, `ç`, `מ`
replace_string = 005A, `đ`, `צ`
replace_string = 005D, `ø`, `ת`
replace_string = 0060, `ij`, `ץ`
replace_string = 0063, `ł`, `.`
</Patch>


<Patch>
patch_name = `Turkish keyboard`
patch_enable = `no`
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Turkish alternatives.
#
# Enable uppercase for `ß` key
replace_bytes = 711920, 00 26, 01 26
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `EN/TR`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `!`
replace_string = 0003, `à`, `q`
replace_string = 0006, `è`, `w`
replace_string = 0009, `ì`, `e`
replace_string = 000C, `ò`, `r`
replace_string = 000F, `ù`, `t`
replace_string = 0012, `á`, `y`
replace_string = 0015, `é`, `u`
replace_string = 0018, `í`, `ı`
replace_string = 001B, `ó`, `o`
replace_string = 001E, `ú`, `p`
replace_string = 0021, `ý`, `ü`
# Third row, left to right:
#replace_string = 0024, `œ\0`, `’`
replace_string = 0027, `â`, `a`
replace_string = 002A, `ê`, `s`
replace_string = 002D, `î`, `d`
replace_string = 0030, `ô`, `f`
replace_string = 0033, `û`, `g`
replace_string = 0036, `ä`, `h`
replace_string = 0039, `ë`, `j`
replace_string = 003C, `ï`, `k`
replace_string = 003F, `ö`, `l`
replace_string = 0042, `ü`, `ş`
replace_string = 0045, `ÿ`, `ğ`
# Bottom row, left to right:
replace_string = 0048, `ã`, `z`
replace_string = 004B, `ñ`, `x`
replace_string = 004E, `õ`, `c`
replace_string = 0051, `å`, `v`
replace_string = 0054, `ß`, `b`
replace_string = 0057, `ç`, `n`
replace_string = 005A, `đ`, `m`
replace_string = 005D, `ø`, `ö`
replace_string = 0060, `ij`, `ç`
replace_string = 0063, `ł`, `i`
</Patch>


<Patch>
patch_name = `Bulgarian keyboard`
patch_enable = `no`
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Bulgarian alternatives.
#  
# Enable uppercase for `ß` key
replace_bytes = 711920, 00 26, 01 26
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `абв`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `!`
replace_string = 0003, `à`, `я`
replace_string = 0006, `è`, `в`
replace_string = 0009, `ì`, `е`
replace_string = 000C, `ò`, `р`
replace_string = 000F, `ù`, `т`
replace_string = 0012, `á`, `ъ`
replace_string = 0015, `é`, `у`
replace_string = 0018, `í`, `и`
replace_string = 001B, `ó`, `о`
replace_string = 001E, `ú`, `п`
replace_string = 0021, `ý`, `ч`
# Third row, left to right:
replace_string = 0024, `œ`, `?`
replace_string = 0027, `â`, `а`
replace_string = 002A, `ê`, `с`
replace_string = 002D, `î`, `д`
replace_string = 0030, `ô`, `ф`
replace_string = 0033, `û`, `г`
replace_string = 0036, `ä`, `х`
replace_string = 0039, `ë`, `й`
replace_string = 003C, `ï`, `к`
replace_string = 003F, `ö`, `л`
replace_string = 0042, `ü`, `ш`
replace_string = 0045, `ÿ`, `щ`
# Bottom row, left to right:
replace_string = 0048, `ã`, `з`
replace_string = 004B, `ñ`, `ь`
replace_string = 004E, `õ`, `ц`
replace_string = 0051, `å`, `ж`
replace_string = 0054, `ß`, `б`
replace_string = 0057, `ç`, `н`
replace_string = 005A, `đ`, `м`
replace_string = 005D, `ø`, `ю`
replace_string = 0060, `ij`, `,`
replace_string = 0063, `ł`, `.`
</Patch>


<Patch>
patch_name = `Greek keyboard`
patch_enable = `no`
# patch_group = `Keyboard alternatives`
#
## Replaces keys on the Extended Latin keypad with Greek alternatives.
#
# Enable uppercase for `ß` key
replace_bytes = 711920, 00 26, 01 26
# Replace layout sign
find_base_address = `ÉÀÇ`
replace_string = 0000, `ÉÀÇ`, `EN/GR`
# Change keyboard layout
find_base_address = `æ\0à\0è\0ì\0`
# Second row, left to right:
replace_string = 0000, `æ`, `!`
replace_string = 0003, `à`, `ά`
replace_string = 0006, `è`, `ς`
replace_string = 0009, `ì`, `ε`
replace_string = 000C, `ò`, `ρ`
replace_string = 000F, `ù`, `τ`
replace_string = 0012, `á`, `υ`
replace_string = 0015, `é`, `θ`
replace_string = 0018, `í`, `ι`
replace_string = 001B, `ó`, `ο`
replace_string = 001E, `ú`, `π`
replace_string = 0021, `ý`, `-`
# Third row, left to right:
replace_string = 0024, `œ`, `?`
replace_string = 0027, `â`, `α`
replace_string = 002A, `ê`, `σ`
replace_string = 002D, `î`, `δ`
replace_string = 0030, `ô`, `φ`
replace_string = 0033, `û`, `γ`
replace_string = 0036, `ä`, `η`
replace_string = 0039, `ë`, `ξ`
replace_string = 003C, `ï`, `κ`
replace_string = 003F, `ö`, `λ`
replace_string = 0042, `ü`, `ή`
replace_string = 0045, `ÿ`, `ώ`
# Bottom row, left to right:
replace_string = 0048, `ã`, `ζ`
replace_string = 004B, `ñ`, `χ`
replace_string = 004E, `õ`, `ψ`
replace_string = 0051, `å`, `ω`
replace_string = 0054, `ß`, `β`
replace_string = 0057, `ç`, `ν`
replace_string = 005A, `đ`, `μ`
replace_string = 005D, `ø`, `,`
replace_string = 0060, `ij`, `.`
replace_string = 0063, `ł`, `ύ`
</Patch>

A new patch to Reduce the size of the header menu bar by 33% including the title header in KePub books. (nickel.patch)

A new patch `Force user font-family in ePubs`.

A new patch `KePub text-rendering options` can enable ligatures in KePub books and fix the em-dash justification problem.

`Brightness fine control`


If anyone else has patches for firmware 4.1.7729 post them in this thread and I'll include a link here.

[Terisa de morgan]

Thank you very much, the "Search in library by default" is the only patch I was missing.

[SCION]

Thank you.

[Martina Schein]

Thank you very much, GeoffR. You are the greatest.

[jamalau]

Thank you GeoffR, for this very fast release!
Is it possible to edit these patches, so doese they work in the ne FW?

Changing the info panel in full size screensaver

Dictionary frame size

Increase The Books Cover Size In The Library

Increasing The View Details Container
__________________

[hkckoo]

do I need to always remove patches made in previous firmware version if I want to upgrade to a newer firmware or am I good just upgrading the firmware directly and then applying the patches once again?

[JSWolf]

Originally Posted by hkckoo

do I need to always remove patches made in previous firmware version if I want to upgrade to a newer firmware or am I good just upgrading the firmware directly and then applying the patches once again?

When updating the firmware, you do not need to remove the patches before you update.

[handocjo]

Thank you GeoffR
I would like to add a Korean keyboard. Can you give me advice?

[oren64]

Originally Posted by jamalau

Is it possible to edit these patches, so doese they work in the ne FW?

Changing the info panel in full size screensaver

Dictionary frame size

Increase The Books Cover Size In The Library

Increasing The View Details Container

[GeoffR]

Thanks oren64, I've added links in post #2.

[GeoffR]

Originally Posted by handocjo

Thank you GeoffR
I would like to add a Korean keyboard. Can you give me advice?

I don't know whether it is possible to make a Korean keyboard for this firmware. It will require some experimenting, but I don't have a device running this firmware and am reluctant to upgrade my Glo yet as it is my only ereader and it is working very nicely with firmware 3.19.5761.

I think the problem might that the Korean characters are encoded as three bytes in UTF-8, while the other languages that have worked with the keyboard are encoded as two bytes. Each keyboard letter has three bytes allocated, but I don't know if they are stored as individual characters or as strings, I suspect the latter, and so the third zero byte might be an end-of-string marker.

The way to find out for sure is to try an experiment using one of the other keyboard patches, but modified so that the third zero byte is overwritten, for example:

replace_string = 0000, `š\0`, `ㅂ`
replace_string = 0003, `ž\0`, `ㄷ`

If the keys are stored as individual characters then the patched keyboard would have one character on each key, but if they are stored as strings then one key will have both characters and the other will have just the second character.

(Edit: Everything above refers to the Extended Latin keypad you see when the UI is set to a Latin-like language. The keyboard you see when Japanese is selected might be completely different and maybe that is what you would need to patch for Korean, but I have no experience with that at all.)

[jackie_w]

I'm making this post to see if there is any general interest in a patch to reduce (not eliminate) the size of the top header menubar thereby reducing what many have described as 'screen wastage' in kepubs.

In the last few days I've been tinkering with pipcat's alternative method for patching the nickel file. I discovered that it's currently quite easy to reduce the height of the top menubar. See attached images for example.

First image: a typical kepub page on an AuraOne with GeoffR's 'Custom Footer' patch plus my 'Reduce Header by 33%' patch.

Second image: same page when tapped to show top and bottom menus. Without the 'Reduce Header' patch both top and bottom menubars are 13mm in height. With the extra patch the top menubar is 8.5mm.

In truth the height could be reduced to any number of pixels you like, but I chose reducing by 33% as a first stab.

What I'm not sure about is whether those who describe the top header in kepubs as 'waste' are more than happy to just use the 'full-screen' option. In which case I won't bother pursuing this.

If there is any interest I can use GeoffR's makepatch utility to create a suitable 4.1.7729-specific addition to nickel.patch

[oren64]

@jackie_w:I like how it look, what's the streems numbers in nickel-extracted.css the patch changes?

[surquizu]

Originally Posted by jackie_w

I'm making this post to see if there is any general interest in a patch to reduce (not eliminate) the size of the top header menubar thereby reducing what many have described as 'screen wastage' in kepubs.

In the last few days I've been tinkering with pipcat's alternative method for patching the nickel file. I discovered that it's currently quite easy to reduce the height of the top menubar. See attached images for example.

First image: a typical kepub page on an AuraOne with GeoffR's 'Custom Footer' patch plus my 'Reduce Header by 33%' patch.

Second image: same page when tapped to show top and bottom menus. Without the 'Reduce Header' patch both top and bottom menubars are 13mm in height. With the extra patch the top menubar is 8.5mm.

In truth the height could be reduced to any number of pixels you like, but I chose reducing by 33% as a first stab.

What I'm not sure about is whether those who describe the top header in kepubs as 'waste' are more than happy to just use the 'full-screen' option. In which case I won't bother pursuing this.

If there is any interest I can use GeoffR's makepatch utility to create a suitable 4.1.7729-specific addition to nickel.patch

I like it!