limine/README.md

225 lines
7.8 KiB
Markdown

# Limine
### What is Limine?
Limine is a modern, advanced, portable, multiprotocol bootloader, also used
as the reference implementation for the [Limine boot protocol](/PROTOCOL.md).
### Limine's boot menu
![Reference screenshot](/screenshot.png?raw=true "Reference screenshot")
[Photo by Lívia Bittencourt](https://www.pexels.com/photo/big-sea-waves-under-rainbow-and-cloudy-sky-4636525/)
### Supported architectures
* IA-32 (32-bit x86)
* x86_64
* aarch64 (arm64)
### Supported boot protocols
* Linux
* [Limine](/PROTOCOL.md)
* Multiboot 1
* Multiboot 2
* Chainloading
### Supported filesystems
* ext2/3/4
* FAT12/16/32
* ISO9660 (CDs/DVDs)
Even though these are the filesystems Limine supports directly, *any*
filesystem can be utilised by the kernel provided that the kernel (and any
needed modules) are on a directly supported filesystem.
### Supported partitioning schemes
* MBR
* GPT
* Unpartitioned media
### Minimum system requirements
For 32-bit x86 systems, support is only ensured starting with those with
Pentium Pro (i686) class CPUs.
All x86_64 and aarch64 (UEFI) systems are supported.
## Binary releases
For convenience, for point releases, binaries are distributed. These binaries
are shipped in the `-binary` branches and tags of this repository
(see [branches](https://github.com/limine-bootloader/limine/branches/all) and
[tags](https://github.com/limine-bootloader/limine/tags)).
For example, to clone the latest binary release of the `v4.x` branch one can do
```bash
git clone https://github.com/limine-bootloader/limine.git --branch=v4.x-branch-binary --depth=1
```
or, to clone a specific binary point release (for example `v4.20220927.0`)
```bash
git clone https://github.com/limine-bootloader/limine.git --branch=v4.20220927.0-binary --depth=1
```
In order to rebuild `limine-deploy`, simply run `make` in the binary
release directory.
`limine-deploy.exe` binaries are provided for Windows.
## Building the bootloader
*The following steps are not necessary if cloning a binary release. If so, skip to*
*"Installing Limine binaries".*
### Prerequisites
In order to build Limine, the following programs have to be installed:
common UNIX tools (also known as `coreutils`),
`GNU make`, `grep`, `sed`, `find`, `awk`, `gzip`, `nasm`, `mtools`
(optional, necessary to build `limine-cd-efi.bin`).
Furthermore, `gcc` or `llvm/clang` must also be installed, alongside
the respective binutils.
### Configure
If using a release tarball (recommended, see https://github.com/limine-bootloader/limine/releases),
run `./configure` directly.
If checking out from the repository, run `./bootstrap` first in order to download the
necessary dependencies and generate the configure script (`GNU autoconf` and `GNU automake` required).
`./configure` takes arguments and environment variables; for more information on
these, run `./configure --help`.
**`./configure` by default does not build any Limine port. Make sure to read the**
**output of `./configure --help` and enable any or all ports!**
To build using the LLVM toolchain, pass `CROSS_TOOLCHAIN=llvm` to `./configure`.
Limine supports both in-tree and out-of-tree builds. Simply run the `configure`
script from the directory you wish to execute the build in. The following `make`
commands are supposed to be ran inside the build directory.
### Building Limine
To build Limine, run:
```bash
make # (or gmake where applicable)
```
The generated bootloader files are going to be in `./bin`.
## Installing Limine binaries
This step is optional as the bootloader binaries can be used from the `./bin` or
release directory just fine. This step will only install them to `share`, `include`, and
`bin` directories in the specified prefix (default is `/usr/local`, see
`./configure --help`, or the `PREFIX` variable if installing from a binary release).
To install Limine, run:
```bash
make install # (or gmake where applicable)
```
## How to use
### UEFI
The `BOOT{IA32,X64,AA64}.EFI` files are vaild EFI applications that can be simply copied to
the `/EFI/BOOT` directory of a FAT formatted EFI system partition. These files can
be installed there and coexist with a BIOS installation of Limine (see below) so
that the disk will be bootable on both BIOS and UEFI systems.
The boot device must to contain the `limine.cfg` file in
either the root or the `boot` directory of one of the partitions, formatted
with a supported file system (the ESP partition is recommended).
### BIOS/MBR
In order to install Limine on a MBR device (which can just be a raw image file),
run `limine-deploy` as such:
```bash
limine-deploy <path to device/image>
```
The boot device must to contain the `limine.sys` and `limine.cfg` files in
either the root or the `boot` directory of one of the partitions, formatted
with a supported file system.
### BIOS/GPT
If using a GPT formatted device, there are 2 options one can follow for
installation:
* Specifying a dedicated stage 2 partition.
* Letting `limine-deploy` attempt to embed stage 2 within GPT structures.
In case one wants to specify a stage 2 partition, create a partition on the GPT
device of at least 32KiB in size, and pass the 1-based number of the partition
to `limine-deploy` as a second argument; such as:
```bash
limine-deploy <path to device/image> <1-based stage 2 partition number>
```
In case one wants to let `limine-deploy` embed stage 2 within GPT's structures,
simply omit the partition number, and invoke `limine-deploy` the same as one
would do for an MBR partitioned device.
The boot device must to contain the `limine.sys` and `limine.cfg` files in
either the root or the `boot` directory of one of the partitions, formatted
with a supported file system.
### BIOS/UEFI hybrid ISO creation
In order to create a hybrid ISO with Limine, place the
`limine-cd-efi.bin`, `limine-cd.bin`, `limine.sys`, and `limine.cfg` files
into a directory which will serve as the root of the created ISO.
(`limine.sys` and `limine.cfg` must either be in the root or inside a `boot`
subdirectory; `limine-cd-efi.bin` and `limine-cd.bin` can reside
anywhere).
Place any other file you want to be on the final ISO in said directory, then
run:
```
xorriso -as mkisofs -b <relative path of limine-cd.bin> \
-no-emul-boot -boot-load-size 4 -boot-info-table \
--efi-boot <relative path of limine-cd-efi.bin> \
-efi-boot-part --efi-boot-image --protective-msdos-label \
<root directory> -o image.iso
```
*Note: `xorriso` is required.*
And do not forget to also run `limine-deploy` on the generated image:
```
limine-deploy image.iso
```
`<relative path of limine-cd.bin>` is the relative path of
`limine-cd.bin` inside the root directory.
For example, if it was copied in `<root directory>/boot/limine-cd.bin`,
it would be `boot/limine-cd.bin`.
`<relative path of limine-cd-efi.bin>` is the relative path of
`limine-cd-efi.bin` inside the root directory.
For example, if it was copied in
`<root directory>/boot/limine-cd-efi.bin`, it would be
`boot/limine-cd-efi.bin`.
### BIOS/PXE boot
The `limine-pxe.bin` binary is a valid PXE boot image.
In order to boot Limine from PXE it is necessary to setup a DHCP server with
support for PXE booting. This can either be accomplished using a single DHCP
server or your existing DHCP server and a proxy DHCP server such as dnsmasq.
`limine.cfg` and `limine.sys` are expected to be on the server used for boot.
### Configuration
The `limine.cfg` file contains Limine's configuration.
An example `limine.cfg` file can be found in [`test/limine.cfg`](https://github.com/limine-bootloader/limine/blob/trunk/test/limine.cfg).
More info on the format of `limine.cfg` can be found in [`CONFIG.md`](https://github.com/limine-bootloader/limine/blob/trunk/CONFIG.md).
## Acknowledgments
Limine uses a stripped-down version of [tinf](https://github.com/jibsen/tinf).
## Discord server
We have a [Discord server](https://discord.gg/QEeZMz4) if you need support,
info, or you just want to hang out with us.