From 6817874c0b6fc575c150dc5c0a103c30f853a0b6 Mon Sep 17 00:00:00 2001
From: Yukai Wu <wuyukai0403@qq.com>
Date: Fri, 17 Jan 2025 21:16:34 +0800
Subject: [PATCH] parse MCFG table & dummy pcie module

---
 README.md                   |  2 ++
 kernel/src/acpi.rs          | 31 ++++++++++++++++++++++++++++++-
 kernel/src/lib.rs           |  1 +
 kernel/src/main.rs          |  3 ++-
 kernel/src/pcie/enumrate.rs |  0
 kernel/src/pcie/mod.rs      |  1 +
 6 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 kernel/src/pcie/enumrate.rs
 create mode 100644 kernel/src/pcie/mod.rs

diff --git a/README.md b/README.md
index c0cc8cc..4f95e1f 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
 # DoglinkOS-2nd
 
 支持加载`GNU/MicroFish`
+
+已放弃BIOS启动支持，请用UEFI（毕竟虚拟机都能用UEFI了）
diff --git a/kernel/src/acpi.rs b/kernel/src/acpi.rs
index 745efec..3ece914 100644
--- a/kernel/src/acpi.rs
+++ b/kernel/src/acpi.rs
@@ -45,9 +45,28 @@ pub struct MADT {
     flags: u32,
 }
 
+#[derive(Debug, Copy, Clone)]
+#[repr(packed)]
+pub struct PCIE_CFG_ALLOC {
+    base_addr: u64,
+    pci_segment_group_number: u16,
+    start_pci_bus_number: u8,
+    end_pci_bus_number: u8,
+    reserved: u32,
+}
+
+#[derive(Debug)]
+#[repr(packed)]
+pub struct MCFG {
+    header: ACPI_table_header,
+    reserved: u64,
+    alloc: PCIE_CFG_ALLOC,
+}
+
 pub static mut rsdp: * const RSDP = 0 as * const RSDP;
 pub static mut xsdt: * const XSDT = 0 as * const XSDT;
 pub static mut madt: * const MADT = 0 as * const MADT;
+pub static mut mcfg: * const MCFG = 0 as * const MCFG;
 
 pub fn init(res: &RsdpResponse) {
     unsafe {
@@ -56,11 +75,15 @@ pub fn init(res: &RsdpResponse) {
         xsdt = phys_to_virt((*rsdp).xsdt_addr) as * const XSDT;
         // println!("{:?}", *xsdt);
         for i in 0..16 {
+            if (*xsdt).pointers[i] == 0 {
+                break;
+            }
             let head = phys_to_virt((*xsdt).pointers[i]) as * const ACPI_table_header;
             if (*head).signature == [65, 80, 73, 67] { // "APIC"
                 madt = head as * const MADT;
-                break;
                 // println!("{:?}", *madt);
+            } else if (*head).signature == [77, 67, 70, 71] { // "MCFG"
+                mcfg = head as * const MCFG;
             }
         }
     }
@@ -91,3 +114,9 @@ pub fn parse_madt() -> u64 {
     }
     res
 }
+
+pub fn parse_mcfg() {
+    unsafe {
+        println!("{:#?}", (*mcfg).alloc);
+    }
+}
diff --git a/kernel/src/lib.rs b/kernel/src/lib.rs
index 1ea94bf..4f22329 100644
--- a/kernel/src/lib.rs
+++ b/kernel/src/lib.rs
@@ -7,3 +7,4 @@ pub mod mm;
 pub mod apic;
 pub mod acpi;
 pub mod cpu;
+pub mod pcie;
diff --git a/kernel/src/main.rs b/kernel/src/main.rs
index b64b41a..4e736a7 100644
--- a/kernel/src/main.rs
+++ b/kernel/src/main.rs
@@ -6,7 +6,7 @@ use DoglinkOS_2nd::console::{init as init_console, clear as clear_console, puts
 use DoglinkOS_2nd::int::{init as init_interrupt, register as register_interrupt_handler};
 use DoglinkOS_2nd::mm::init as init_mm;
 use DoglinkOS_2nd::apic::{local::init as init_lapic, io::init as init_ioapic};
-use DoglinkOS_2nd::acpi::{init as init_acpi, parse_madt};
+use DoglinkOS_2nd::acpi::{init as init_acpi, parse_madt, parse_mcfg};
 use DoglinkOS_2nd::cpu::show_cpu_info;
 use DoglinkOS_2nd::println;
 use limine::request::{FramebufferRequest, HhdmRequest, RsdpRequest, RequestsEndMarker, RequestsStartMarker};
@@ -58,6 +58,7 @@ extern "C" fn kmain() -> ! {
     let ioapic_phys_addr = parse_madt();
     init_ioapic(ioapic_phys_addr);
     show_cpu_info();
+    parse_mcfg();
     hang();
 }
 
diff --git a/kernel/src/pcie/enumrate.rs b/kernel/src/pcie/enumrate.rs
new file mode 100644
index 0000000..e69de29
diff --git a/kernel/src/pcie/mod.rs b/kernel/src/pcie/mod.rs
new file mode 100644
index 0000000..e8bb32f
--- /dev/null
+++ b/kernel/src/pcie/mod.rs
@@ -0,0 +1 @@
+pub mod enumrate;