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Update linux-bootstrap-1.md

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0xAX 2015-12-28 17:15:16 +06:00
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Booting/linux-bootstrap-1.md
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@ -388,7 +388,7 @@ This can lead to 3 different scenarios:
Let's look at all three of these scenarios:
1. `ss` has a correct address (0x10000). In this case we go to label [2](https://github.com/torvalds/linux/blob/master/arch/x86/boot/header.S#L481):
* `ss` has a correct address (0x10000). In this case we go to label [2](https://github.com/torvalds/linux/blob/master/arch/x86/boot/header.S#L481):
```
2: andw $~3, %dx
@ -403,7 +403,7 @@ Here we can see the alignment of `dx` (contains `sp` given by bootloader) to 4 b
![stack](http://oi58.tinypic.com/16iwcis.jpg)
2. In the second scenario, (`ss` != `ds`). First of all put the [_end](https://github.com/torvalds/linux/blob/master/arch/x86/boot/setup.ld#L52) (address of end of setup code) value in `dx` and check the `loadflags` header field with the `testb` instruction to see whether we can use the heap or not. [loadflags](https://github.com/torvalds/linux/blob/master/arch/x86/boot/header.S#L321) is a bitmask header which is defined as:
* In the second scenario, (`ss` != `ds`). First of all put the [_end](https://github.com/torvalds/linux/blob/master/arch/x86/boot/setup.ld#L52) (address of end of setup code) value in `dx` and check the `loadflags` header field with the `testb` instruction to see whether we can use the heap or not. [loadflags](https://github.com/torvalds/linux/blob/master/arch/x86/boot/header.S#L321) is a bitmask header which is defined as:
```C
#define LOADED_HIGH (1<<0)
@ -429,7 +429,7 @@ If the `CAN_USE_HEAP` bit is set, put `heap_end_ptr` in `dx` which points to `_e
![stack](http://oi62.tinypic.com/dr7b5w.jpg)
3. When `CAN_USE_HEAP` is not set, we just use a minimal stack from `_end` to `_end + STACK_SIZE`:
* When `CAN_USE_HEAP` is not set, we just use a minimal stack from `_end` to `_end + STACK_SIZE`:
![minimal stack](http://oi60.tinypic.com/28w051y.jpg)