How to create a file of the exact size of a directory (and its files), to hold a FAT32 filesystem?
I'm trying to create a file with the minimum-enough size to contain a FAT32 filesystem, which, in turn, mirrors the contents of a directory (an ESP structure). This is needed to create an UEFI-bootable ISO image.
I've managed to create the file successfully (the ISO image boots), but I've had to create it with a fixed size, and not the actual size of its contents.
Here's what I have done to achieve it:
BOOT_IMG_DATA=$(mktemp -d)
BOOT_IMG=$ISO_DIR/boot/efi.img
mkdir -p $(dirname $BOOT_IMG)
truncate -s 4M $BOOT_IMG
mkfs.vfat $BOOT_IMG
mount $BOOT_IMG $BOOT_IMG_DATA
mkdir -p $BOOT_IMG_DATA/efi/boot
grub-mkimage
-C xz
-O x86_64-efi
-p /boot/grub
-o $BOOT_IMG_DATA/efi/boot/bootx64.efi
boot linux search normal configfile
part_gpt btrfs fat iso9660 loopback
test keystatus gfxmenu regexp probe
efi_gop efi_uga all_video gfxterm font
echo read ls cat png jpeg halt reboot
umount $BOOT_IMG_DATA
That code is part of a script that generates an UEFI-bootable ISO image. The whole script is here: https://github.com/Nitrux/mkiso/blob/master/mkiso#L79-L100.
I need a way to create a file that will contain the ESP structure with the exact size to hold both the ESP data (directories and files) and the FAT32 metadada. How can I achieve this?
linux uefi fat32 sh
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
migrated from stackoverflow.com Jan 4 at 3:28
This question came from our site for professional and enthusiast programmers.
add a comment |
I'm trying to create a file with the minimum-enough size to contain a FAT32 filesystem, which, in turn, mirrors the contents of a directory (an ESP structure). This is needed to create an UEFI-bootable ISO image.
I've managed to create the file successfully (the ISO image boots), but I've had to create it with a fixed size, and not the actual size of its contents.
Here's what I have done to achieve it:
BOOT_IMG_DATA=$(mktemp -d)
BOOT_IMG=$ISO_DIR/boot/efi.img
mkdir -p $(dirname $BOOT_IMG)
truncate -s 4M $BOOT_IMG
mkfs.vfat $BOOT_IMG
mount $BOOT_IMG $BOOT_IMG_DATA
mkdir -p $BOOT_IMG_DATA/efi/boot
grub-mkimage
-C xz
-O x86_64-efi
-p /boot/grub
-o $BOOT_IMG_DATA/efi/boot/bootx64.efi
boot linux search normal configfile
part_gpt btrfs fat iso9660 loopback
test keystatus gfxmenu regexp probe
efi_gop efi_uga all_video gfxterm font
echo read ls cat png jpeg halt reboot
umount $BOOT_IMG_DATA
That code is part of a script that generates an UEFI-bootable ISO image. The whole script is here: https://github.com/Nitrux/mkiso/blob/master/mkiso#L79-L100.
I need a way to create a file that will contain the ESP structure with the exact size to hold both the ESP data (directories and files) and the FAT32 metadada. How can I achieve this?
linux uefi fat32 sh
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
migrated from stackoverflow.com Jan 4 at 3:28
This question came from our site for professional and enthusiast programmers.
You mean likemkfs.vfat -C /path/to/image_to_create.img sizewhere you specify thesizeyou want for the image? You can thenmountthe image and copy the files to it as needed. You can do the same thing withddand then callmkfs.vfaton the image itself.
– David C. Rankin
Jan 3 at 20:15
@DavidC.Rankin, what I need is thesizeparameter, in that case.
– Luis Lavaire
Jan 3 at 20:49
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12
add a comment |
I'm trying to create a file with the minimum-enough size to contain a FAT32 filesystem, which, in turn, mirrors the contents of a directory (an ESP structure). This is needed to create an UEFI-bootable ISO image.
I've managed to create the file successfully (the ISO image boots), but I've had to create it with a fixed size, and not the actual size of its contents.
Here's what I have done to achieve it:
BOOT_IMG_DATA=$(mktemp -d)
BOOT_IMG=$ISO_DIR/boot/efi.img
mkdir -p $(dirname $BOOT_IMG)
truncate -s 4M $BOOT_IMG
mkfs.vfat $BOOT_IMG
mount $BOOT_IMG $BOOT_IMG_DATA
mkdir -p $BOOT_IMG_DATA/efi/boot
grub-mkimage
-C xz
-O x86_64-efi
-p /boot/grub
-o $BOOT_IMG_DATA/efi/boot/bootx64.efi
boot linux search normal configfile
part_gpt btrfs fat iso9660 loopback
test keystatus gfxmenu regexp probe
efi_gop efi_uga all_video gfxterm font
echo read ls cat png jpeg halt reboot
umount $BOOT_IMG_DATA
That code is part of a script that generates an UEFI-bootable ISO image. The whole script is here: https://github.com/Nitrux/mkiso/blob/master/mkiso#L79-L100.
I need a way to create a file that will contain the ESP structure with the exact size to hold both the ESP data (directories and files) and the FAT32 metadada. How can I achieve this?
linux uefi fat32 sh
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
I'm trying to create a file with the minimum-enough size to contain a FAT32 filesystem, which, in turn, mirrors the contents of a directory (an ESP structure). This is needed to create an UEFI-bootable ISO image.
I've managed to create the file successfully (the ISO image boots), but I've had to create it with a fixed size, and not the actual size of its contents.
Here's what I have done to achieve it:
BOOT_IMG_DATA=$(mktemp -d)
BOOT_IMG=$ISO_DIR/boot/efi.img
mkdir -p $(dirname $BOOT_IMG)
truncate -s 4M $BOOT_IMG
mkfs.vfat $BOOT_IMG
mount $BOOT_IMG $BOOT_IMG_DATA
mkdir -p $BOOT_IMG_DATA/efi/boot
grub-mkimage
-C xz
-O x86_64-efi
-p /boot/grub
-o $BOOT_IMG_DATA/efi/boot/bootx64.efi
boot linux search normal configfile
part_gpt btrfs fat iso9660 loopback
test keystatus gfxmenu regexp probe
efi_gop efi_uga all_video gfxterm font
echo read ls cat png jpeg halt reboot
umount $BOOT_IMG_DATA
That code is part of a script that generates an UEFI-bootable ISO image. The whole script is here: https://github.com/Nitrux/mkiso/blob/master/mkiso#L79-L100.
I need a way to create a file that will contain the ESP structure with the exact size to hold both the ESP data (directories and files) and the FAT32 metadada. How can I achieve this?
linux uefi fat32 sh
linux uefi fat32 sh
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
edited Jan 4 at 5:34
Luis Lavaire
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
asked Jan 3 at 20:07
Luis LavaireLuis Lavaire
216
216
migrated from stackoverflow.com Jan 4 at 3:28
This question came from our site for professional and enthusiast programmers.
migrated from stackoverflow.com Jan 4 at 3:28
This question came from our site for professional and enthusiast programmers.
You mean likemkfs.vfat -C /path/to/image_to_create.img sizewhere you specify thesizeyou want for the image? You can thenmountthe image and copy the files to it as needed. You can do the same thing withddand then callmkfs.vfaton the image itself.
– David C. Rankin
Jan 3 at 20:15
@DavidC.Rankin, what I need is thesizeparameter, in that case.
– Luis Lavaire
Jan 3 at 20:49
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12
add a comment |
You mean likemkfs.vfat -C /path/to/image_to_create.img sizewhere you specify thesizeyou want for the image? You can thenmountthe image and copy the files to it as needed. You can do the same thing withddand then callmkfs.vfaton the image itself.
– David C. Rankin
Jan 3 at 20:15
@DavidC.Rankin, what I need is thesizeparameter, in that case.
– Luis Lavaire
Jan 3 at 20:49
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12
You mean like
mkfs.vfat -C /path/to/image_to_create.img size where you specify the size you want for the image? You can then mount the image and copy the files to it as needed. You can do the same thing with dd and then call mkfs.vfat on the image itself.– David C. Rankin
Jan 3 at 20:15
You mean like
mkfs.vfat -C /path/to/image_to_create.img size where you specify the size you want for the image? You can then mount the image and copy the files to it as needed. You can do the same thing with dd and then call mkfs.vfat on the image itself.– David C. Rankin
Jan 3 at 20:15
@DavidC.Rankin, what I need is the
size parameter, in that case.– Luis Lavaire
Jan 3 at 20:49
@DavidC.Rankin, what I need is the
size parameter, in that case.– Luis Lavaire
Jan 3 at 20:49
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12
add a comment |
1 Answer
1
active
oldest
votes
The right tool for this task is du.
mkfs.vfat -C $BOOT_IMG
$(( ($(du -b $BOOT_IMG_DATA | tail -n 1 | awk '{ print $1 }') / 1024 + 511) / 1024 ))
That command will create the file $BOOT_IMG, which will have enough size to keep the contents of $BOOT_IMG_DATA.
answered 5 hours ago
Luis LavaireLuis Lavaire
216
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "3"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1390369%2fhow-to-create-a-file-of-the-exact-size-of-a-directory-and-its-files-to-hold-a%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The right tool for this task is du.
mkfs.vfat -C $BOOT_IMG
$(( ($(du -b $BOOT_IMG_DATA | tail -n 1 | awk '{ print $1 }') / 1024 + 511) / 1024 ))
That command will create the file $BOOT_IMG, which will have enough size to keep the contents of $BOOT_IMG_DATA.
answered 5 hours ago
Luis LavaireLuis Lavaire
216
add a comment |
The right tool for this task is du.
mkfs.vfat -C $BOOT_IMG
$(( ($(du -b $BOOT_IMG_DATA | tail -n 1 | awk '{ print $1 }') / 1024 + 511) / 1024 ))
That command will create the file $BOOT_IMG, which will have enough size to keep the contents of $BOOT_IMG_DATA.
answered 5 hours ago
Luis LavaireLuis Lavaire
216
add a comment |
The right tool for this task is du.
mkfs.vfat -C $BOOT_IMG
$(( ($(du -b $BOOT_IMG_DATA | tail -n 1 | awk '{ print $1 }') / 1024 + 511) / 1024 ))
That command will create the file $BOOT_IMG, which will have enough size to keep the contents of $BOOT_IMG_DATA.
answered 5 hours ago
Luis LavaireLuis Lavaire
216
The right tool for this task is du.
mkfs.vfat -C $BOOT_IMG
$(( ($(du -b $BOOT_IMG_DATA | tail -n 1 | awk '{ print $1 }') / 1024 + 511) / 1024 ))
That command will create the file $BOOT_IMG, which will have enough size to keep the contents of $BOOT_IMG_DATA.
answered 5 hours ago
Luis LavaireLuis Lavaire
216
answered 5 hours ago
Luis LavaireLuis Lavaire
216
answered 5 hours ago
Luis LavaireLuis Lavaire
216
answered 5 hours ago
Luis LavaireLuis Lavaire
216
216
add a comment |
add a comment |
Thanks for contributing an answer to Super User!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1390369%2fhow-to-create-a-file-of-the-exact-size-of-a-directory-and-its-files-to-hold-a%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
You mean like
mkfs.vfat -C /path/to/image_to_create.img sizewhere you specify thesizeyou want for the image? You can thenmountthe image and copy the files to it as needed. You can do the same thing withddand then callmkfs.vfaton the image itself.– David C. Rankin
Jan 3 at 20:15
@DavidC.Rankin, what I need is the
sizeparameter, in that case.– Luis Lavaire
Jan 3 at 20:49
I would make a disk image, then shrink it after for archival.
– juniorRubyist
Jan 4 at 17:12