Windows recovery broke grub, recovery attempt broke access to endeavourOS

[Evo]

Background:
Two main SSDs:
sda1 popOS
sda2 windows10 boot sector
sda3 windows10

sdb1 grub2 core.img
sdb2 EndeavourOS with a btrfs filesystem (@, @home, @snapshots)

Yesterday I wanted to give the Win10 partition a bit more space via gparted and I received help in this thread to fix all of the Linux-related errors. I was able to boot into EndeavorOS and PopOS just fine, Windows 10 still asked for a recovery tool.

Cause of the current issue:
Today I ran the Win10 recovery tool from USB and that in turn overwrote grub, all I got after boot was the Win10 blue screen telling me to fix my windows install. Should have just wiped Win10 and reinstalled it. ;;

Attempts to fix:
I booted into my EndeavourOS live USB, chrooted into my PopOS (this was a mistake, as I later realized it was EndeavourOS which my grub ran under previously), ran (I believe) grub-install, grub-update and os-prober on sda1 (popOS) and only PopOS and Win10 were detected.

The newly generated grub.cfg looks like this:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
if [ "${initrdfail}" = 2 ]; then
   set initrdfail=
elif [ "${initrdfail}" = 1 ]; then
   set next_entry="${prev_entry}"
   set prev_entry=
   save_env prev_entry
   if [ "${next_entry}" ]; then
      set initrdfail=2
   fi
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="0"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}
function initrdfail {
    if [ -n "${have_grubenv}" ]; then if [ -n "${partuuid}" ]; then
      if [ -z "${initrdfail}" ]; then
        set initrdfail=1
        if [ -n "${boot_once}" ]; then
          set prev_entry="${default}"
          save_env prev_entry
        fi
      fi
      save_env initrdfail
    fi; fi
}
function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_msdos
insmod ext2
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
else
  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
fi
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_GB
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=30
else
  if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=countdown
    set timeout=5
  # Fallback hidden-timeout code in case the timeout_style feature is
  # unavailable.
  elif sleep --interruptible 5 ; then
    set timeout=0
  fi
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
	set gfxpayload="${1}"
	if [ "${1}" = "keep" ]; then
		set vt_handoff=vt.handoff=7
	else
		set vt_handoff=
	fi
}
if [ "${recordfail}" != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
menuentry 'Pop GNU/Linux' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-399cabc3-c5a4-4b58-965f-745351207608' {
	recordfail
	load_video
	gfxmode $linux_gfx_mode
	insmod gzio
	if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
	insmod part_msdos
	insmod ext2
	set root='hd0,msdos1'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
	else
	  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
	fi
	linux	/vmlinuz-linux root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
	initrd	/initramfs-linux.img
}
submenu 'Advanced options for Pop GNU/Linux' $menuentry_id_option 'gnulinux-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
	menuentry 'Pop GNU/Linux, with Linux linux' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux linux ...'
		linux	/vmlinuz-linux root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/initramfs-linux.img
	}
	menuentry 'Pop GNU/Linux, with Linux linux (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux linux ...'
		linux	/vmlinuz-linux root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/initramfs-linux.img
	}
	menuentry 'Pop GNU/Linux, with Linux 5.8.0-7630-generic' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-7630-generic-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.8.0-7630-generic ...'
		linux	/boot/vmlinuz-5.8.0-7630-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.8.0-7630-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.8.0-7630-generic (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-7630-generic-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.8.0-7630-generic ...'
		linux	/boot/vmlinuz-5.8.0-7630-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.8.0-7630-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.8.0-7625-generic' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-7625-generic-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.8.0-7625-generic ...'
		linux	/boot/vmlinuz-5.8.0-7625-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.8.0-7625-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.8.0-7625-generic (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.8.0-7625-generic-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.8.0-7625-generic ...'
		linux	/boot/vmlinuz-5.8.0-7625-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.8.0-7625-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.4.0-7642-generic' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-7642-generic-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.4.0-7642-generic ...'
		linux	/boot/vmlinuz-5.4.0-7642-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.4.0-7642-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.4.0-7642-generic (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-7642-generic-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.4.0-7642-generic ...'
		linux	/boot/vmlinuz-5.4.0-7642-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.4.0-7642-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.4.0-7634-generic' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-7634-generic-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.4.0-7634-generic ...'
		linux	/boot/vmlinuz-5.4.0-7634-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.4.0-7634-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.4.0-7634-generic (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-7634-generic-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.4.0-7634-generic ...'
		linux	/boot/vmlinuz-5.4.0-7634-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.4.0-7634-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.3.0-7648-generic' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.3.0-7648-generic-advanced-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		gfxmode $linux_gfx_mode
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.3.0-7648-generic ...'
		linux	/boot/vmlinuz-5.3.0-7648-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro  quiet splash $vt_handoff
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.3.0-7648-generic
	}
	menuentry 'Pop GNU/Linux, with Linux 5.3.0-7648-generic (recovery mode)' --class pop --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.3.0-7648-generic-recovery-399cabc3-c5a4-4b58-965f-745351207608' {
		recordfail
		load_video
		insmod gzio
		if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		echo	'Loading Linux 5.3.0-7648-generic ...'
		linux	/boot/vmlinuz-5.3.0-7648-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro recovery nomodeset dis_ucode_ldr 
		echo	'Loading initial ramdisk ...'
		initrd	/boot/initrd.img-5.3.0-7648-generic
	}
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/10_linux_zfs ###
### END /etc/grub.d/10_linux_zfs ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows 10 (on /dev/sda2)' --class windows --class os $menuentry_id_option 'osprober-chain-920E739D0E7378D5' {
	insmod part_msdos
	insmod ntfs
	set root='hd0,msdos2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos2 --hint-efi=hd0,msdos2 --hint-baremetal=ahci0,msdos2  920E739D0E7378D5
	else
	  search --no-floppy --fs-uuid --set=root 920E739D0E7378D5
	fi
	parttool ${root} hidden-
	drivemap -s (hd0) ${root}
	chainloader +1
}
menuentry 'Windows 7 (on /dev/sdc1)' --class windows --class os $menuentry_id_option 'osprober-chain-6276CC3176CC082D' {
	insmod part_msdos
	insmod ntfs
	set root='hd2,msdos1'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd2,msdos1 --hint-efi=hd2,msdos1 --hint-baremetal=ahci2,msdos1  6276CC3176CC082D
	else
	  search --no-floppy --fs-uuid --set=root 6276CC3176CC082D
	fi
	parttool ${root} hidden-
	chainloader +1
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
  set timeout=10
fi
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

…after doublechecking with the grub.cfg on my EndeavourOS install I realized I let that grub handle everything since I back when I installed it.

Coincidentally I remember doing it that way so that if Win10 ever really screws everything up I could go as far as wiping that entire SSD if need be without damage to my new and shiny EndeavourOS. Old me was definitely smarter than current me.

Said "original" grub.cfg looks like this and resembles the structure I was used to before Win10 did its thing:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
  load_env
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="EndeavourOS, on linux"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_gpt
insmod btrfs
set root='hd1,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
else
  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
fi
    font="/@/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_GB
  insmod gettext
fi
terminal_input console
terminal_output gfxterm
insmod part_gpt
insmod btrfs
set root='hd1,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
else
  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
fi
insmod gfxmenu
loadfont ($root)/@/boot/grub/themes/EndeavourOS/unifont-regular-16.pf2
insmod png
set theme=($root)/@/boot/grub/themes/EndeavourOS/theme.txt
export theme
if [ x$feature_timeout_style = xy ] ; then
  set timeout_style=menu
  set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
  set timeout=5
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux_proxy ###





if [ "x$default" = 'EndeavourOS, on linux' ]; then default='Advanced options for EndeavourOS>EndeavourOS, on linux'; fi;
menuentry "EndeavourOS, on linux" --class endeavouros --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-32166223-8f4f-4f69-9149-fe979df93e58' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_gpt
	insmod btrfs
	set root='hd1,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
	else
	  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
	fi
	echo	'Loading kernel linux ...'
	linux	/@/boot/vmlinuz-linux root=UUID=32166223-8f4f-4f69-9149-fe979df93e58 rw rootflags=subvol=@  quiet loglevel=3 nowatchdog
	echo	'Loading initial ramdisk ...'
	initrd	/@/boot/intel-ucode.img /@/boot/initramfs-linux.img
}
### END /etc/grub.d/10_linux_proxy ###

### BEGIN /etc/grub.d/30_os-prober_proxy ###















menuentry "Windows 10 (on /dev/sda2)" --class windows --class os $menuentry_id_option 'osprober-chain-920E739D0E7378D5' {
	insmod part_msdos
	insmod ntfs
	set root='hd0,msdos2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos2 --hint-efi=hd0,msdos2 --hint-baremetal=ahci0,msdos2  920E739D0E7378D5
	else
	  search --no-floppy --fs-uuid --set=root 920E739D0E7378D5
	fi
	parttool ${root} hidden-
	drivemap -s (hd0) ${root}
	chainloader +1
}
menuentry "Pop GNU/Linux (on /dev/sda1)" --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/boot/vmlinuz-5.8.0-7630-generic--399cabc3-c5a4-4b58-965f-745351207608' {
		insmod part_msdos
		insmod ext2
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  399cabc3-c5a4-4b58-965f-745351207608
		else
		  search --no-floppy --fs-uuid --set=root 399cabc3-c5a4-4b58-965f-745351207608
		fi
		linux /boot/vmlinuz-5.8.0-7630-generic root=UUID=399cabc3-c5a4-4b58-965f-745351207608 ro quiet splash $vt_handoff
		initrd /boot/initrd.img-5.8.0-7630-generic
}
### END /etc/grub.d/30_os-prober_proxy ###

### BEGIN /etc/grub.d/33_uefi-firmware ###
### END /etc/grub.d/33_uefi-firmware ###

### BEGIN /etc/grub.d/34_linux_proxy ###
menuentry "EndeavourOS, on linux (fallback initramfs)" --class endeavouros --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-fallback-32166223-8f4f-4f69-9149-fe979df93e58' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_gpt
	insmod btrfs
	set root='hd1,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
	else
	  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
	fi
	echo	'Loading kernel linux ...'
	linux	/@/boot/vmlinuz-linux root=UUID=32166223-8f4f-4f69-9149-fe979df93e58 rw rootflags=subvol=@  quiet loglevel=3 nowatchdog
	echo	'Loading initial ramdisk ...'
	initrd	/@/boot/intel-ucode.img /@/boot/initramfs-linux-fallback.img
}
menuentry "EndeavourOS, on linux-lts" --class endeavouros --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-advanced-32166223-8f4f-4f69-9149-fe979df93e58' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_gpt
	insmod btrfs
	set root='hd1,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
	else
	  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
	fi
	echo	'Loading kernel linux-lts ...'
	linux	/@/boot/vmlinuz-linux-lts root=UUID=32166223-8f4f-4f69-9149-fe979df93e58 rw rootflags=subvol=@  quiet loglevel=3 nowatchdog
	echo	'Loading initial ramdisk ...'
	initrd	/@/boot/intel-ucode.img /@/boot/initramfs-linux-lts.img
}
menuentry "EndeavourOS, on linux-lts (fallback initramfs)" --class endeavouros --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-fallback-32166223-8f4f-4f69-9149-fe979df93e58' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_gpt
	insmod btrfs
	set root='hd1,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  32166223-8f4f-4f69-9149-fe979df93e58
	else
	  search --no-floppy --fs-uuid --set=root 32166223-8f4f-4f69-9149-fe979df93e58
	fi
	echo	'Loading kernel linux-lts ...'
	linux	/@/boot/vmlinuz-linux-lts root=UUID=32166223-8f4f-4f69-9149-fe979df93e58 rw rootflags=subvol=@  quiet loglevel=3 nowatchdog
	echo	'Loading initial ramdisk ...'
	initrd	/@/boot/intel-ucode.img /@/boot/initramfs-linux-lts-fallback.img
}
### END /etc/grub.d/34_linux_proxy ###

### BEGIN /etc/grub.d/35_linux_xen ###
### END /etc/grub.d/35_linux_xen ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg
fi
### END /etc/grub.d/41_custom ###

### BEGIN /etc/grub.d/42_snapshots-btrfs ###
submenu 'EndeavourOS snapshots' {
    configfile "${prefix}/grub-btrfs.cfg"
}
### END /etc/grub.d/42_snapshots-btrfs ###

### BEGIN /etc/grub.d/43_grub-customizer_menu_color_helper ###
### END /etc/grub.d/43_grub-customizer_menu_color_helper ###

I’m currently back in the EndeavourOS live medium and os-prober (via chroot into EndeavourOS) still just returns this (ignore the Win7 result, old remnant):

/dev/sda1:Pop!_OS 20.04 LTS (20.04):Pop:linux
/dev/sda2:Windows 10:Windows:chain
/dev/sdc1:Windows 7:Windows1:chain

Question:
How do I put the “EndeavourOS grub” back into control with the old grub.cfg? I did make a backup of @/boot/ this time around at least, those files should be untouched as of now.

Once this is fixed I plan to just disconnect the EndeavourOS SSD and then re-install Windows on the partition of the other one. That’s how I originally set this up and it made Windows10 behave just fine without interfering with grub.

Apologies for showing up here again back to back & thank you for your time in advance.

[pebcak]

What does
efibootmgr -v
return?

If you have an EFI boot entry for EnOS, perhaps you might need to change the boot priority.

If not you would need to arch-chroot to your EnOS system and reinstall the bootloader.

See the following post on how to chroot into a systen on BTRFS:

Grub unknown filesystem/can't chroot after installing Windows 11

Try this: umount /mnt mount -o subvol=@ /dev/nvme0n1p6 /mnt mount /dev/nvme0n1p2 /mnt/boot/efi arch-chroot /mnt

Adapt the /dev/xxxx part to your actual setup.

Also:

https://discovery.endeavouros.com/system-rescue/repair-a-non-booting-grub/2021/03/

[Evo]

@pebcak

What does
efibootmgr -v
return?

[root@archiso /]# efibootmgr -v
EFI variables are not supported on this system.

@pebcak

If you have an EFI boot entry for EnOS, perhaps you might need to change the boot priority.

If not you would need to arch-chroot to your EnOS system and reinstall the bootloader.

See the following post on how to chroot into a systen on BTRFS:
Grub unknown filesystem/can't chroot after installing Windows 11 - #4 by dalto

Adapt the /dev/xxxx part to your actual setup.

Also:

https://discovery.endeavouros.com/system-rescue/repair-a-non-booting-grub/2021/03/

I’m following the advice here to chroot into my btrfs:

sudo mount /dev/sdb2 /mnt -o subvol=@
sudo arch-chroot /mnt

Same user, same idea, that should be fine so far.

…does my efibootmgr -v result mean I can just follow the “non-booting GRUB”-guide for BIOS systems? I’d just rather triple check before I break anything else.

e: If I run os-prober from chroot it’s normal that it only detects the other OS’s, right?

[pebcak]

@Evo

…does my efibootmgr -v result mean I can just follow the “non-booting GRUB”-guide for BIOS systems?

Sorry. Wrong of me to assume that you had a UEFI system.
I guess it should be fine to follow the instructions for the BIOS system to reinstall the bootloader.

[pebcak]

Please note that you might need to do the following for os-prober to run and detect your other systems:

Os-prober grub

This means that if you have other systems on your drive they will not be detected and added to the Grub boot menu since os-prober will not be run (the Warning text said it much better ). You could add GRUB_DISABLE_OS_PROBER=false to /etc/default/grub and regenerate grub.cfg sudo grub-mkconfig -o /boot/grub/grub.cfg if you want/need os-prober to run again.

[Evo]

Thank you so much, that did the trick. The non-booting GRUB repair was really all that was needed.

…there’s something about bootloaders not working that terrifies me, but it seems they’re really not that scary on Linux systems. Now to fix Windows10 and by ‘fix’ I probably mean ‘burn down and reinstall after some minor backups’…

Have a good day!

[pebcak]

You are welcome! Glad you got it sorted out!
Have a nice day you too!