Prepare multicore_bringup for aarch64 support (#889)

* Move `multicore_bringup/lib.rs` to x86_64-specific module file.

* Remove `max_framebuffer_resolution` parameter in `multicore_bringup`,
  use the fixed constant definition from `kernel_config`.

* Restore arch-gate for early exceptions init in `nano_core`

Author: NathanRoyer

kernel/captain/src/lib.rs

@@ -55,16 +55,8 @@ impl DropAfterInit {
     }
 }
 
-#[cfg(target_arch = "x86_64")]
 pub use multicore_bringup::MulticoreBringupInfo;
 
-/// TODO: in the future this could be defined here or re-exported from another aarch64 crate.
-#[cfg(target_arch = "aarch64")]
-pub struct MulticoreBringupInfo {
-    // nothing needed on aarch64 yet
-}
-
-
 /// Initialize the Captain, which is the main crate that "steers the ship" of Theseus. 
 ///
 /// This does the rest of the initialization procedures so that the OS 
@@ -144,7 +136,6 @@ pub fn init(
     let ap_count = multicore_bringup::handle_ap_cores(
         &kernel_mmi_ref,
         multicore_info,
-        Some(kernel_config::display::FRAMEBUFFER_MAX_RESOLUTION),
     )?;
     #[cfg(not(target_arch = "x86_64"))]
     let ap_count = 0;

kernel/multicore_bringup/Cargo.toml

@@ -3,46 +3,25 @@ authors = ["Kevin Boos <kevinaboos@gmail.com>"]
 name = "multicore_bringup"
 description = "Support for bringing up other CPU cores (APs) from the main core (BSP)"
 version = "0.1.0"
+edition = "2021"
 
 [dependencies]
 spin = "0.9.4"
 volatile = "0.2.7"
 zerocopy = "0.5.0"
 log = "0.4.8"
-
-[dependencies.memory]
-path = "../memory"
-
-[dependencies.stack]
-path = "../stack"
-
-[dependencies.kernel_config]
-path = "../kernel_config"
-
-[dependencies.pit_clock_basic]
-path = "../pit_clock_basic"
-
-[dependencies.mod_mgmt]
-path = "../mod_mgmt"
-
-[dependencies.acpi]
-path = "../acpi"
-
-[dependencies.apic]
-path = "../apic"
-
-[dependencies.cpu]
-path = "../cpu"
-
-[dependencies.ap_start]
-path = "../ap_start"
-
-[dependencies.madt]
-path = "../acpi/madt"
-
-[dependencies.pause]
-path = "../pause"
-
+memory = { path = "../memory" }
+stack = { path = "../stack" }
+cpu = { path = "../cpu" }
+ap_start = { path = "../ap_start" }
+kernel_config = { path = "../kernel_config" }
+pit_clock_basic = { path = "../pit_clock_basic" }
+mod_mgmt = { path = "../mod_mgmt" }
+acpi = { path = "../acpi" }
+apic = { path = "../apic" }
+madt = { path = "../acpi/madt" }
+pause = { path = "../pause" }
 
 [lib]
 crate-type = ["rlib"]
+path = "src/x86_64.rs"

kernel/multicore_bringup/src/lib.rs renamed to kernel/multicore_bringup/src/x86_64.rs

@@ -7,22 +7,7 @@
 #![no_std]
 #![feature(let_chains)]
 
-extern crate alloc;
 #[macro_use] extern crate log;
-extern crate spin;
-extern crate volatile;
-extern crate zerocopy;
-extern crate memory;
-extern crate pit_clock_basic;
-extern crate stack;
-extern crate kernel_config;
-extern crate apic;
-extern crate acpi;
-extern crate madt;
-extern crate mod_mgmt;
-extern crate ap_start;
-extern crate pause;
-extern crate cpu;
 
 use core::{
     convert::TryInto,
@@ -34,7 +19,7 @@ use spin::Mutex;
 use volatile::Volatile;
 use zerocopy::FromBytes;
 use memory::{VirtualAddress, PhysicalAddress, MappedPages, PteFlags, MmiRef};
-use kernel_config::memory::{PAGE_SIZE, PAGE_SHIFT, KERNEL_STACK_SIZE_IN_PAGES};
+use kernel_config::{memory::{PAGE_SIZE, PAGE_SHIFT, KERNEL_STACK_SIZE_IN_PAGES}, display::FRAMEBUFFER_MAX_RESOLUTION};
 use apic::{LocalApic, get_lapics, current_cpu, has_x2apic, bootstrap_cpu, cpu_count};
 use ap_start::{kstart_ap, AP_READY_FLAG};
 use madt::{Madt, MadtEntry, find_nmi_entry_for_processor};
@@ -206,7 +191,6 @@ pub struct MulticoreBringupInfo {
 pub fn handle_ap_cores(
     kernel_mmi_ref: &MmiRef,
     multicore_info: MulticoreBringupInfo,
-    max_framebuffer_resolution: Option<(u16, u16)>,
 ) -> Result<u32, &'static str> {
     let MulticoreBringupInfo {
         ap_start_realmode_begin,
@@ -276,7 +260,7 @@ pub fn handle_ap_cores(
     // Here, we set up the data items that will be accessible to the APs when they boot up.
     // We only set the values of fields that are the same for ALL APs here;
     // values that change for each AP are set individually in `bring_up_ap()` below.
-    let (max_width, max_height) = max_framebuffer_resolution.unwrap_or((u16::MAX, u16::MAX));
+    let (max_width, max_height) = FRAMEBUFFER_MAX_RESOLUTION;
     ap_trampoline_data.ap_max_fb_width.write(max_width);
     ap_trampoline_data.ap_max_fb_height.write(max_height);
     ap_trampoline_data.ap_gdt.write(ap_gdt.value().try_into().map_err(|_| "AP_GDT physical address larger than u32::MAX")?);

kernel/nano_core/src/lib.rs

@@ -112,8 +112,10 @@ where
         build_info::CUSTOM_CFG_STR,
     );
 
-    exceptions_early::init(Some(double_fault_stack_top));
-    println!("early_setup(): initialized early IDT with exception handlers.");
+    #[cfg(target_arch = "x86_64")] {
+        exceptions_early::init(Some(double_fault_stack_top));
+        println!("early_setup(): initialized early IDT with exception handlers.");
+    }
 
     let rsdp_address = boot_info.rsdp();
     println!("nano_core(): bootloader-provided RSDP address: {:X?}", rsdp_address);