michaelkuc6/blog_os
1
0
Fork 0
mirror of https://github.com/phil-opp/blog_os.git synced 2025-12-16 14:27:49 +00:00
Code Issues Projects Releases Wiki Activity

Set up a cargo runner to make cargo xrun work

Browse Source
This commit is contained in:
Philipp Oppermann
2019-04-25 13:17:40 +02:00
parent 22bc414972
commit 52cbb1e756
1 changed files with 22 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
blog/content/second-edition/posts/02-minimal-rust-kernel/index.md
View File

@@ -431,5 +431,27 @@ It is also possible to write it to an USB stick and boot it on a real machine:
Where `sdX` is the device name of your USB stick. **Be careful** to choose the correct device name, because everything on that device is overwritten.
After writing the image to the USB stick, you can run it on real hardware by booting from it. You probably need to use a special boot menu or change the boot order in your BIOS configuration to boot from the USB stick. Note that it currently doesn't work for UEFI machines, since the `bootloader` crate has no UEFI support yet.
### Using `cargo run`
To make it easier to run our kernel in QEMU, we can set the `runner` configuration key for cargo:
```toml
# in .cargo/config
[target.'cfg(target_os = "none")']
runner = "bootimage runner"
```
The `target.'cfg(target_os = "none")'` table applies to all targets that have set the `"os"` field of their target configuration file to `"none"`. This includes our `x86_64-blog_os.json` target. The `runner` key specifies the command that should be invoked for `cargo run`. The command is run after a successful build with the executable path passed as first argument. See the [cargo documentation][cargo configuration] for more details.
The `bootimage runner` command is specifically designed to be usable as a `runner` executable. It links the given executable with the project's bootloader dependency and then launches QEMU. See the [Readme of `bootimage`] for more details and possible configuration options.
[Readme of `bootimage`]: https://github.com/rust-osdev/bootimage
Now we can use `cargo xrun` to compile our kernel and boot it in QEMU. Like `xbuild`, the `xrun` subcommand builds the sysroot crates before invoking the actual cargo command. The subcommand is also provided by `cargo-xbuild`, so you don't need to install an additional tool.
## What's next?
In the next post, we will explore the VGA text buffer in more detail and write a safe interface for it. We will also add support for the `println` macro.