Fix minor typos. (#675)

blog/content/second-edition/posts/01-freestanding-rust-binary/index.md

@@ -145,7 +145,7 @@ Language items are special functions and types that are required internally by t
 [`Copy`]: https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html
 [copy code]: https://github.com/rust-lang/rust/blob/485397e49a02a3b7ff77c17e4a3f16c653925cb3/src/libcore/marker.rs#L296-L299
 
-Providing own implementations of language items would be possible, but this should only be done as a last resort. The reason is that language items are highly unstable implementation details and not even type checked (so the compiler doesn't even check if a function has the right argument types). Fortunately, there is a more stable ways to fix the above language item error.
+Providing own implementations of language items would be possible, but this should only be done as a last resort. The reason is that language items are highly unstable implementation details and not even type checked (so the compiler doesn't even check if a function has the right argument types). Fortunately, there is a more stable way to fix the above language item error.
 
 The `eh_personality` language item marks a function that is used for implementing [stack unwinding]. By default, Rust uses unwinding to run the destructors of all live stack variables in case of a [panic]. This ensures that all used memory is freed and allows the parent thread to catch the panic and continue execution. Unwinding, however, is a complicated process and requires some OS specific libraries (e.g. [libunwind] on Linux or [structured exception handling] on Windows), so we don't want to use it for our operating system.
 

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

@@ -137,7 +137,7 @@ We also target `x86_64` systems with our kernel, so our target specification wil
     "target-pointer-width": "64",
     "target-c-int-width": "32",
     "os": "none",
-    "executables": true,
+    "executables": true
 }
 ```
 

blog/content/second-edition/posts/03-vga-text-buffer/index.md

@@ -303,7 +303,7 @@ We can add a dependency on the `volatile` crate by adding it to the `dependencie
 volatile = "0.2.6"
 ```
 
-The `0.2.3` is the [semantic] version number. For more information, see the [Specifying Dependencies] guide of the cargo documentation.
+The `0.2.6` is the [semantic] version number. For more information, see the [Specifying Dependencies] guide of the cargo documentation.
 
 [semantic]: http://semver.org/
 [Specifying Dependencies]: http://doc.crates.io/specifying-dependencies.html

blog/content/second-edition/posts/06-double-faults/index.md

@@ -194,7 +194,7 @@ struct InterruptStackTable {
 }
 ```
 
-For each exception handler, we can choose a stack from the IST through the `options` field in the corresponding [IDT entry]. For example, we could use the first stack in the IST for our double fault handler. Then the CPU would automatically switch to this stack whenever a double fault occurs. This switch would happen before anything is pushed, so it would prevent the triple fault.
+For each exception handler, we can choose a stack from the IST through the `stack_pointers` field in the corresponding [IDT entry]. For example, we could use the first stack in the IST for our double fault handler. Then the CPU would automatically switch to this stack whenever a double fault occurs. This switch would happen before anything is pushed, so it would prevent the triple fault.
 
 [IDT entry]: @/second-edition/posts/05-cpu-exceptions/index.md#the-interrupt-descriptor-table
 

blog/content/second-edition/posts/09-paging-implementation/index.md

@@ -655,7 +655,7 @@ The function takes the `physical_memory_offset` as an argument and returns a new
 
 [`OffsetPageTable::new`]: https://docs.rs/x86_64/0.7.5/x86_64/structures/paging/mapper/struct.OffsetPageTable.html#method.new
 
-The `active_level_4_table` function should be only called from the `init` function from now on because it can easily to aliased mutable references when called multiple times, which can cause undefined behavior. For this reason, we make the function private by removing the `pub` specifier.
+The `active_level_4_table` function should be only called from the `init` function from now on because it can easily lead to aliased mutable references when called multiple times, which can cause undefined behavior. For this reason, we make the function private by removing the `pub` specifier.
 
 We now can use the `MapperAllSizes::translate_addr` method instead of our own `memory::translate_addr` function. We only need to change a few lines in our `kernel_main`:
 

blog/content/second-edition/posts/10-heap-allocation/index.md

@@ -87,7 +87,7 @@ Let's go through an example:
 
 ![The inner function calls `allocate(size_of([u32; 3]))`, writes `z.write([1,2,3]);`, and returns `(z as *mut u32).offset(i)`. The outer function does `deallocate(y, size_of(u32))` on the returned value `y`.](call-stack-heap.svg)
 
-Here the `inner` function uses heap memory instead of static variables for storing `z`. It first allocates a memory block of the required size, which returns a `*mut u8` [raw pointer]. It then uses the [`ptr::write`] method to write the array `[1,2,3]` to it. In the last step, it uses the [`offset`] function to calculate a pointer to the `i`th element and then returns it. (Note that we omitted some required casts and unsafe blocks in this example function for brevity.)
+Here the `inner` function uses heap memory instead of static variables for storing `z`. It first allocates a memory block of the required size, which returns a `*mut u32` [raw pointer]. It then uses the [`ptr::write`] method to write the array `[1,2,3]` to it. In the last step, it uses the [`offset`] function to calculate a pointer to the `i`th element and then returns it. (Note that we omitted some required casts and unsafe blocks in this example function for brevity.)
 
 [raw pointer]: https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html#dereferencing-a-raw-pointer
 [`ptr::write`]: https://doc.rust-lang.org/core/ptr/fn.write.html
@@ -475,7 +475,8 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
     println!("Hello World{}", "!");
     blog_os::init();
 
-    let mut mapper = unsafe { memory::init(boot_info.physical_memory_offset) };
+    let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
+    let mut mapper = unsafe { memory::init(phys_mem_offset) };
     let mut frame_allocator = unsafe {
         BootInfoFrameAllocator::init(&boot_info.memory_map)
     };