[kernel] E: Check lower memory regions are available

src/hal/mod.rs

@@ -63,13 +63,20 @@ pub fn init(
     memory_regions: &mut LinkedList<MemoryRegion<VirtualAddress>>,
     mmio_regions: &mut LinkedList<TruncatedMemoryRegion<VirtualAddress>>,
     madt: &Option<MadtInfo>,
+    mem_lower: Option<u32>,
 ) -> Result<Hal, Error> {
     info!("initializing hardware abstraction layer...");
 
     let mut ioports: IoPortAllocator = IoPortAllocator::new();
     let mut ioaddresses: IoMemoryAllocator = IoMemoryAllocator::new();
     let mut platform: Platform =
-        platform::init(&mut ioports, &mut ioaddresses, memory_regions, mmio_regions, madt)?;
+        platform::init(
+            &mut ioports, 
+            &mut ioaddresses, 
+            memory_regions, 
+            mmio_regions, 
+            madt,
+            mem_lower)?;
 
     // Initialize the interrupt manager.
     let intman: Option<InterruptManager> = match platform.arch.controller.take() {

src/hal/platform/bootinfo.rs

@@ -31,6 +31,8 @@ use ::alloc::collections::LinkedList;
 pub struct BootInfo {
     /// ACPI MADT information.
     pub madt: Option<MadtInfo>,
+    /// Lower memory size.
+    pub mem_lower: Option<u32>,
     /// General-purpose memory regions.
     pub memory_regions: LinkedList<MemoryRegion<VirtualAddress>>,
     /// Memory-mapped I/O regions.
@@ -52,6 +54,7 @@ impl BootInfo {
     /// # Parameters
     ///
     /// - `madt`: ACPI MADT information.
+    /// - `mem_lower`: Available Lower memory.
     /// - `memory_regions`: General-purpose memory regions.
     /// - `mmio_regions`: Memory-mapped I/O regions.
     /// - `kernel_modules`: Kernel modules.
@@ -62,12 +65,14 @@ impl BootInfo {
     ///
     pub fn new(
         madt: Option<MadtInfo>,
+        mem_lower: Option<u32>,
         memory_regions: LinkedList<MemoryRegion<VirtualAddress>>,
         mmio_regions: LinkedList<TruncatedMemoryRegion<VirtualAddress>>,
         kernel_modules: LinkedList<KernelModule>,
     ) -> Self {
         Self {
             madt,
+            mem_lower,
             memory_regions,
             mmio_regions,
             kernel_modules,

src/hal/platform/microvm.rs

@@ -200,7 +200,7 @@ pub fn parse_bootinfo(magic: u32, info: usize) -> Result<BootInfo, Error> {
         kernel_modules.push_back(module);
     }
 
-    Ok(BootInfo::new(None, LinkedList::new(), LinkedList::new(), kernel_modules))
+    Ok(BootInfo::new(None, None, LinkedList::new(), LinkedList::new(), kernel_modules))
 }
 
 pub fn init(
@@ -209,6 +209,7 @@ pub fn init(
     _memory_regions: &mut LinkedList<MemoryRegion<VirtualAddress>>,
     _mmio_regions: &mut LinkedList<TruncatedMemoryRegion<VirtualAddress>>,
     madt: &Option<MadtInfo>,
+    _mem_lower: Option<u32>
 ) -> Result<Platform, Error> {
     Ok(Platform {
         arch: x86::init(ioports, ioaddresses, madt)?,

src/hal/platform/pc/mboot/basic_mem_info.rs

@@ -5,7 +5,7 @@
 // Imports
 //==================================================================================================
 
-use ::error::{
+use ::sys::error::{
     Error,
     ErrorCode,
 };

src/hal/platform/pc/mod.rs

@@ -33,7 +33,10 @@ use ::arch::{
     cpu::pic,
     mem,
 };
-use ::sys::error::Error;
+use ::sys::error::{
+    Error,
+    ErrorCode,
+};
 use ::sys::{
     config,
     mm::VirtualAddress,
@@ -107,7 +110,16 @@ pub struct Platform {
 #[cfg(feature = "bios")]
 fn register_bios_data_area(
     memory_regions: &mut LinkedList<MemoryRegion<VirtualAddress>>,
+    mem_lower_size: usize,
 ) -> Result<(), Error> {
+
+    // This is possible because mem_lower_size start at address 0x0.
+    if mem_lower_size < bios::BiosDataArea::BASE + mem::PAGE_SIZE {
+        let reason: &str = "bios data memory region is not available";
+        error!("register_bios_data_area(): {:?}", reason);
+        return Err(Error::new(ErrorCode::OutOfMemory, reason));
+    }
+
     let bios_data_area: MemoryRegion<VirtualAddress> = MemoryRegion::new(
         "bios data area",
         VirtualAddress::from_raw_value(bios::BiosDataArea::BASE)?
@@ -156,6 +168,7 @@ pub fn init(
     memory_regions: &mut LinkedList<MemoryRegion<VirtualAddress>>,
     mmio_regions: &mut LinkedList<TruncatedMemoryRegion<VirtualAddress>>,
     madt: &Option<MadtInfo>,
+    mem_lower: Option<u32>,
 ) -> Result<Platform, Error> {
     // Register I/O ports for 8259 PIC.
     ioports.register_read_write(pic::PIC_CTRL_MASTER as u16)?;
@@ -182,8 +195,25 @@ pub fn init(
 
     // Register BIOS data area.
     #[cfg(feature = "bios")]
-    register_bios_data_area(memory_regions)?;
+    let mem_lower_size = match mem_lower {
+        Some(mem_lower_size) => {
+            mem_lower_size as usize
+        },
+        None => {
+            let reason: &str = "availability of lower memory is not known";
+            error!("init(): {:?}", reason);
+            return Err(Error::new(ErrorCode::InvalidArgument, reason));
+        }
+    };
+
+    register_bios_data_area(memory_regions, mem_lower_size)?;
 
+    // This is possible because mem_lower start at address 0x0.
+    if mem_lower_size < platform::TRAMPOLINE_ADDRESS.into_raw_value() + mem::PAGE_SIZE {
+        let reason: &str = "trampoline memory region is not available";
+        error!("init(): {:?}", reason);
+        return Err(Error::new(ErrorCode::OutOfMemory, reason));
+    }
     // Trampoline.
     let trampoline: MemoryRegion<VirtualAddress> = MemoryRegion::new(
         "trampoline",
@@ -195,7 +225,7 @@ pub fn init(
     memory_regions.push_back(trampoline);
 
     // Register video display memory.
-    // TODO: we should read this region from the multi-boot information passed by Grub.
+    // FIXME: https://github.com/nanvix/kernel/issues/435
     let video_display_memory: TruncatedMemoryRegion<VirtualAddress> = TruncatedMemoryRegion::new(
         "video display memory",
         PageAligned::from_raw_value(0x000a0000)?,
@@ -207,7 +237,7 @@ pub fn init(
     mmio_regions.push_back(video_display_memory);
 
     // Bios memory.
-    // TODO: we should read this region from the multi-boot information passed by Grub.
+    // FIXME: https://github.com/nanvix/kernel/issues/435
     let bios: MemoryRegion<VirtualAddress> = MemoryRegion::new(
         "bios memory",
         VirtualAddress::from_raw_value(0x000c0000)?,

src/kmain.rs

@@ -213,14 +213,19 @@ pub extern "C" fn kmain(kargs: &KernelArguments) {
 
     // Parse kernel arguments.
     info!("parsing kernel arguments...");
-    let (madt, mut memory_regions, mut mmio_regions, kernel_modules): (
+    let (madt, mem_lower, mut memory_regions, mut mmio_regions, kernel_modules): (
         Option<MadtInfo>,
+        Option<u32>,
         LinkedList<MemoryRegion<VirtualAddress>>,
         LinkedList<TruncatedMemoryRegion<VirtualAddress>>,
         LinkedList<KernelModule>,
     ) = match kargs.parse() {
         Ok(bootinfo) => {
-            (bootinfo.madt, bootinfo.memory_regions, bootinfo.mmio_regions, bootinfo.kernel_modules)
+            (bootinfo.madt, 
+             bootinfo.mem_lower, 
+             bootinfo.memory_regions, 
+             bootinfo.mmio_regions, 
+             bootinfo.kernel_modules)
         },
         Err(err) => {
             panic!("failed to parse kernel arguments: {:?}", err);
@@ -255,7 +260,12 @@ pub extern "C" fn kmain(kargs: &KernelArguments) {
         }
     }
 
-    let mut hal: Hal = match hal::init(&mut memory_regions, &mut mmio_regions, &madt) {
+    let mut hal: Hal = match hal::init(
+        &mut memory_regions,
+        &mut mmio_regions,
+        &madt,
+        mem_lower)
+    {
         Ok(hal) => hal,
         Err(err) => {
             panic!("failed to initialize hardware abstraction layer: {:?}", err);