Thank you Glenn !
Your answer was very helpful, the Cutmem i think worked, but the other one
did not.
*From a machine that had already usuntu installed and running, i knew that
if the modifications worked, then if i run in terminal sudo Dmesg , i
should see something like this:*
*[ 0.000000] reserve setup_data: [mem
0x00000000b4018000-0x00000000b401cfff] reserved[ 0.000000] reserve
setup_data: [mem 0x00000000b2018000-0x00000000b201cfff] reserved*
1) So, I started from scratch with an ubuntu iso and rufus. and modified
boot/grub/grug.cfg like you said.
*menuentry "Ubuntu (safe graphics)" { set gfxpayload=keep linux
/casper/vmlinuz nomodeset file=/cdrom/preseed/ubuntu.seed maybe-ubiquity
quiet splash ---
memmap=16K\$0x0000000B4018000,16K\$0x0000000B2018000,4K\$0x0000000B401C000,4K\$0x0000000B201C000
initrd /casper/initrd}*
I was able to boot ubuntu from liveusb, and did sudo Dmesg, i could not
find any address for b4018000 nor b2018000
so pretty much for me it means it failed, and if i run any program later on
there is a high chance that it will crash because of bad memory.
2) So i went back to boot/grub/grug.cfg and added as the first lines the
one you told me:
*cutmem 2949216K 2949232K cutmem 2916448K 2916464K cutmem 2949232K
2949236Kcutmem 2916464K 2916468K*
booted ubuntu live usb, did sudo dmesg ,and i found some "unusable"
addresses for bios-e820 that matched b4018000 and b2018000
[ 0.000000] BIOS-e820: [mem 0x00000000b2018000-0x00000000b201cfff]
unusable
[ 0.000000] BIOS-e820: [mem 0x00000000b4018000-0x00000000b401cfff]
unusable
so pretty much i think the cutmem worked! just need to test for many hours
that there are no crashes using live usb.
At least now i might be able to boot many different linux distros from live
USB too! which is what i was looking for!!
thanks!
On Sat, Nov 26, 2022 at 1:52 AM Project Development <
developm...@efficientek.com> wrote:
> On Mon, Nov 7, 2022 at 9:50 AM James Wabi <imitomx1...@gmail.com> wrote:
> >
> > Thanks vladimir, sadly it did not work. What i did was to include the
> memmap line like this on boot/grub/grub.cfg
> >
> >
> > # This Menu entry brought to you courtesy of
> https://www.pendrivelinux.com/install-grub2-on-usb-from-ubuntu-linux/
> > set timeout=10
> > set default=0
> >
> > menuentry "Run Ubuntu Live ISO" {
> > loopback loop /ubuntu.iso
> > linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/ubuntu.iso
> splash --
> memmap=16K\\\$0x0000000B4018000,16K\\\$0x0000000B2018000,4K\\\$0x0000000B401C000,4K\\\$0x0000000B201C000
>
> I bet your problem here is one too many levels of escaping being done. Try:
>
> linux (loop)/casper/vmlinuz boot=casper
> iso-scan/filename=/ubuntu.iso splash --
>
> memmap=16K\$0x0000000B4018000,16K\$0x0000000B2018000,4K\$0x0000000B401C000,4K\$0x0000000B201C000
>
> A little more generic, and not linux specific way would be to use
> GRUB's cutmem command[1]. Based on the documentation, I think you
> could have the following lines at the top of the grub config:
>
> cutmem 2949216K 2949232K
> cutmem 2916448K 2916464K
> cutmem 2949232K 2949236K
> cutmem 2916464K 2916468K
>
> Glenn
>
> [1] https://www.gnu.org/software/grub/manual/grub/html_node/cutmem.html
>
> >
> > initrd (loop)/casper/initrd
> > }
> >
> > Then i booted ubuntu from live usb, and i wanted to double check if
> those areas in the memory were reserved. So i opened terminal, and executed
> : dmesg
> > A long list of reserved things were displayed but nothing related to
> those specific memory addresses.
> >
> > regards!
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel
>
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