(It seems that the hardinfo utility shows that my motherboard is a 7480 but the laptop's
Dell sticker on the plastic case bottom shows: 7490. Other people seem to have this also.)
I wanted to boot and use my Dell Latitude 7480/7490 laptop with its built-in
micro SDCARD slot. (Especially since when I got this PC, it had no disk
nor SSD nor the standard size SDCARD slot.
For me booting from a SDCARD device, instead of a USB flash drive, also frees up a USB port.)
A 96 gigabyte micro SDCARD costs about ten US dollars and is about the size of a fingernail.
(For UEFI booting, I formatted the micro SDCARD as ntfs and set the boot and esp flags with the GParted utility
by putting the micro SDCARD into an standard size slot on my USB SDCARD reader dongle on another PC.)
With SecureBoot turned off, I was able to boot the Dell Latitude 7490 PC and use both BookwormPup64_10.0.8,
and BookwormPup64_10.0.7 and BookwormPup64_10.0.6 but I could not get the older fossapup64_9.5 to boot.
When BookwormPup64_10.0.8 and BookwormPup64_10.0.7 is running, the boot device icon on the bottom left side
of the screen shows: mm0p1 (not mmcblk0p1.)
(The micro SDCARD hardware, which is: vid=0a5c, pid=5832 USB Broadcom 5880
seems to generate a number of these dmesg -T messages:
mmc0: cannot verify signal voltage switch
pcieport 0000:00:1c.0: Intel SPT PCH root port ACS workaround enabled
The Broadcom 5880 which handles the micro SDCARD wants higher voltage for high speed data transfers and it can not confirm the motherboard is using it.)
I found that the somewhat newer Puppy ISO: fossapup64 9.6 (F96-CE_4) could boot
on my Dell Latitude 7490 microSD slot.
(I believe the somewhat older fossapup64_9.5 is missing some driver modules
for the Dell Latitude 7490's micro SDCARD hardware, which is: vid=0a5c, pid=5832 USB Broadcom 5880
While not the same brand, but Barry had a comment about booting from SDCARDs:
" ... the kernel does not recognise the Realtek card-reader at early bootup,
as the drivers for it are modules ..."
https://bkhome.org/news/201812/kernel-4 ... piled.html
I seem to remember more of his comments about adding modules to the ISO for SDCARD booting,
but I can not find them now.)
(I could get fossapup64_9.5 to boot on my Dell Latitude 7490 laptop when I put the micro SDCARD into
a plastic adapter and then into a standard size USB slot with my USB SDCARD reader dongle.)
===
However, my Dell Latitude 7490 laptop randomly "freezed" with its screen locked up,
sometimes after running a few minutes or sometimes only after running many hours:
I found this:
16 people also have this problem
Responses(96)
https://www.dell.com/community/en/conve ... aa3?page=1
===
and this: Dell Latitude 7480 random hangs when TLP is being used (linux):
Looking for working TLP configuration, which does not lead to system freezes/hangs:
on reddit suggested looking at the command:
dmesg | grep 5832
(Note: The 5832 is the Broadcom micro SDCARD hardware)
===
and finally, I found this:
Low-powered Intel processors and/or laptop processors have a tendency
to randomly hang or crash due to the problems with the power management
features found in low-power Intel chips.
If such a crash happens, you will not see any logs reporting this problem !
i915.enable_dc=0 disables GPU power management.
This does solve random hangs on certain Intel systems, notably
Goldmount and Kaby Lake Refresh chips.
Using this parameter does result in higher power use and shorter
battery life on laptops/notebooks.
And suggests adding the boot argument i915.enable_dc=0 to the kernelstub.
The above is from: https://github.com/pop-os/pop/issues/3346
(Note: no innocent ram memory was harmed in the testing of this fix ! )
My grub.cfg now looks like this:
menuentry ' '{
true
}
menuentry "BookwormPup64_10.0.8 with possible hang fix i915.enable_dc=0 and microcode" {
search --no-floppy --fs-uuid --set=root 046C95624CF5546B
echo "Loading vmlinuz"
linux /BookwormPup64_10.0.8/vmlinuz psubdir=/BookwormPup64_10.0.8 PDRV=mmcblk0p1 pmedia=usbflash pfix=fsck,fsckp,trim i915.enable_dc=0
if [ -e /BookwormPup64_10.0.8/ucode.cpio ]; then
echo "Loading microcode then initrd.gz"
initrd /BookwormPup64_10.0.8/ucode.cpio /BookwormPup64_10.0.8/initrd.gz
else
echo "Loading just initrd.gz"
initrd /BookwormPup64_10.0.8/initrd.gz
fi
}
menuentry ' '{
true
}
===
Perhaps this post might be a little useful for other Dell Latitude 7480/7490 owners and/or people
trying to boot via micro SDCARD readers.
