arno/linux-insides
1
0
Fork 0
mirror of https://github.com/0xAX/linux-insides.git synced 2024-11-15 20:48:57 +00:00
Code Issues Releases Wiki Activity

Merge pull request #131 from diogovk/fix_typos

Browse Source 
Fix a few english typos - "can be runned not"
This commit is contained in:
0xAX 2015-07-17 12:06:48 +05:00
commit 45fe80f242
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Initialization/linux-initialization-1.md
View File

@ -72,7 +72,7 @@ Now we know default physical and virtual addresses of the `startup_64` routine,
subq $_text - __START_KERNEL_map, %rbp
```
Here we just put the `rip-relative` address to the `rbp` register and than subtract `$_text - __START_KERNEL_map` from it. We know that compiled address of the `_text` is `0xffffffff81000000` and `__START_KERNEL_map` contains `0xffffffff81000000`, so `rbp` will contain physical address of the `text` - `0x1000000` after this calculation. We need to calculate it because kernel can be runned not on the default address, but now we know actual physical address.
Here we just put the `rip-relative` address to the `rbp` register and then subtract `$_text - __START_KERNEL_map` from it. We know that compiled address of the `_text` is `0xffffffff81000000` and `__START_KERNEL_map` contains `0xffffffff81000000`, so `rbp` will contain physical address of the `text` - `0x1000000` after this calculation. We need to calculate it because kernel can't be runned on the default address, but now we know the actual physical address.
In the next step we checks that this address is aligned with:
@ -122,7 +122,7 @@ The first step before we started to setup identity paging, need to correct follo
addq %rbp, level2_fixmap_pgt + (506*8)(%rip)
```
Here we need to correct `early_level4_pgt` and other addresses of the page table directories, because as I wrote above, kernel can be runned not at the default `0x1000000` address. `rbp` register contains actuall address so we add to the `early_level4_pgt`, `level3_kernel_pgt` and `level2_fixmap_pgt`. Let's try to understand what this labels means. First of all let's look on their definition:
Here we need to correct `early_level4_pgt` and other addresses of the page table directories, because as I wrote above, kernel can't be runned at the default `0x1000000` address. `rbp` register contains actual address so we add to the `early_level4_pgt`, `level3_kernel_pgt` and `level2_fixmap_pgt`. Let's try to understand what these labels means. First of all let's look on their definition:
```assembly
NEXT_PAGE(early_level4_pgt)