[Updated] Removing quiet and splash options from command line of Debian RPD live USB with persistence

The excuse to remove quiet and splash options from the kernel command line of my Debian RPD live USB with persistence was the tty consoles did not reliably setup increased font size with dpkg-reconfigure console-setup on bootup. I have found xorriso and its alter ego osirrox to extract grub.cfg, remove the quiet and splash options and write it over back in the ISO image.

pi@raspberrypi:~ $ osirrox -dev Downloads/2020-02-12-rpd-x86-buster.iso

-extract boot/grub/grub.cfg grub.cfg
xorriso 1.5.0 : RockRidge filesystem manipulator, libburnia project.
xorriso : NOTE : Loading ISO image tree from LBA 0
xorriso : UPDATE : 5398 nodes read in 1 seconds
xorriso : NOTE : Detected El-Torito boot information which currently is set to be discarded
Drive current: -dev 'Downloads/2020-02-12-rpd-x86-buster.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record : El Torito , MBR isohybrid cyl-align-on GPT APM
Media summary: 1 session, 1527416 data blocks, 2983m data, 521m free
Volume id : 'Debian RPD M-A 1'
xorriso : UPDATE : 1 files restored ( 1828b) in 1 seconds = 0.0xD
Extracted from ISO image: file '/boot/grub/grub.cfg'='/home/pi/grub.cfg'
pi@raspberrypi:~ $ chmod +w grub.cfg
pi@raspberrypi:~ $ nano grub.cfg
pi@raspberrypi:~ $ chmod -w grub.cfg
pi@raspberrypi:~ $ xorriso -indev 2020-02-12-rpd-x86-buster.iso /
-outdev 2020-02-12-rpd-x86-buster-mod.iso /
-map '/home/pi/grub.cfg' '/boot/grub/grub.cfg' /
-overwrite nondir /
-boot_image any keep /
-close off /
-write_type auto /
-stream_recording data /
-commit
xorriso : UPDATE : 5398 nodes read in 1 seconds
xorriso : NOTE : Loading ISO image tree from LBA 0
Drive current: -indev '/mnt/2020-02-12-rpd-x86-buster.iso'
xorriso : NOTE : Detected El-Torito boot information which currently

is set to be discarded
Media current: stdio file, overwriteable
Media summary: 1 session, 1527416 data blocks, 2983m data, 754g free
Media status : is written , is appendable
Boot record : El Torito , MBR isohybrid cyl-align-on GPT APM
Volume id : 'Debian RPD M-A 1'
Media summary: 0 sessions, 0 data blocks, 0 data, 754g free
Drive current: -outdev '/mnt/2020-02-12-rpd-x86-buster-mod.iso'
Media current: stdio file, overwriteable
Media status : is blank
xorriso : UPDATE : 1 files added in 1 seconds
xorriso : UPDATE : Writing: 4512s 0.3% fifo 0% buf 50%
Added to ISO image: file '/boot/grub/grub.cfg'='/home/pi/grub.cfg'
xorriso : NOTE : Keeping boot image unchanged
xorriso : UPDATE : Writing: 2048s 0.1% fifo 2% buf 50%
Writing to '/mnt/2020-02-12-rpd-x86-buster-mod.iso' completed successfully.
xorriso : UPDATE : Writing: 16384s 1.1% fifo 81% buf 50% 17.5xD
...
xorriso : UPDATE : Writing: 1523712s 99.9% fifo 75% buf 50% 18.7xD
ISO image produced: 1525788 sectors
Written to medium : 1525952 sectors at LBA 32
xorriso : UPDATE : 5398 nodes read in 1 seconds
xorriso : NOTE : Re-assessing -outdev '/mnt/2020-02-12-rpd-x86-buster-mod.iso'
xorriso : NOTE : Loading ISO image tree from LBA 0
libburn : SORRY : Read start address 1527415s larger than number of readable blocks 1525984
xorriso : NOTE : Detected El-Torito boot information which currently is set to be kept unchanged

xorriso : NOTE : Tolerated problem event of severity 'SORRY'
Drive current: -dev '/mnt/2020-02-12-rpd-x86-buster-mod.iso'
Media current: stdio file, overwriteable
Media status : is written , is appendable
Boot record : El Torito , MBR cyl-align-on GPT APM
Media summary: 1 session, 1525788 data blocks, 2980m data, 751g free
Volume id : 'Debian RPD M-A 1'
xorriso : NOTE : -return_with SORRY 32 triggered by problem severity SORRY

xorriso : UPDATE : 5398 nodes read in 1 seconds

xorriso : UPDATE : 5398 nodes read in 1 seconds

This made increased font size reliably setup during boot of Debian RPD live USB with persistence.

[Update]

As my cheap USB SATA SSD frequently stopped working with kernel messages that suggested uas

driver is the culprit. So in order to fall back on legacy storage driver, I have looked up the idVendor and

idProduct in dmesg of my cheap USB SATA SSD and added this to the kernel command line:

usb_storage.quirks=2109:0715:u