Link to framebuffer module in migration guide

We moved the framebuffer implementation out of the logger.rs module when we added support for serial logging.

Author: phil-opp

docs/migration/v0.9.md

@@ -33,7 +33,7 @@ This guide summarizes the steps for migrating from `bootloader v0.9.X` to `bootl
   entry_point!(kernel_main, config = &BOOTLOADER_CONFIG);
   ```
   See the [`BootloaderConfig`](https://docs.rs/bootloader_api/0.11/bootloader_api/config/struct.BootloaderConfig.html) struct for all configuration options.
-- The `v0.11` version of the bootloader sets up a pixel-based framebuffer instead of using the VGA text mode. This means that you have to rewrite your screen output code. See the [`common/logger.rs`](../../common/src/logger.rs) module for an example implementation based on the [`noto-sans-mono-bitmap`](https://docs.rs/noto-sans-mono-bitmap/latest/noto_sans_mono_bitmap/index.html) and [`log`](https://docs.rs/log/latest) crates.
+- The `v0.11` version of the bootloader sets up a pixel-based framebuffer instead of using the VGA text mode. This means that you have to rewrite your screen output code. See the [`common/src/framebuffer.rs`](../../common/src/framebuffer.rs) module for an example implementation based on the [`noto-sans-mono-bitmap`](https://docs.rs/noto-sans-mono-bitmap/latest/noto_sans_mono_bitmap/index.html) and [`log`](https://docs.rs/log/latest) crates.
 - If you want to use UEFI booting, you cannot use the [legacy PIC](https://wiki.osdev.org/8259_PIC) for interrupt handling. Instead, you have to set up the [`APIC`](https://wiki.osdev.org/APIC). Unfortunately, we don't have a guide for this yet, but the basic steps are:
   - The `boot_info.rsdp_addr` field will tell you the physical address of the [`RSDP`](https://wiki.osdev.org/RSDP) structure, which is part of the [`ACPI`](https://en.wikipedia.org/wiki/ACPI) standard. Note that `ACPI` (_Advanced Configuration and Power Interface_) and `APIC` (_Advanced Programmable Interrupt Controller_) are completely different things that just have confusingly similar acronyms.
   - Use the [`acpi`](https://docs.rs/acpi/4.1.1/acpi/index.html) crate and its [`AcpiTables::from_rsdp`](https://docs.rs/acpi/4.1.1/acpi/struct.AcpiTables.html#method.from_rsdp) function to load the ACPI tables. Then use the [`platform_info`](https://docs.rs/acpi/4.1.1/acpi/struct.AcpiTables.html#method.platform_info) method and read the [`interrupt_model`](https://docs.rs/acpi/4.1.1/acpi/platform/struct.PlatformInfo.html#structfield.interrupt_model) field of the returned `PlatformInfo`. This field gives you all the necessary information about the system's interrupt controller.