diff options
| author | Anton Kling <anton@kling.gg> | 2023-11-08 15:33:11 +0100 |
|---|---|---|
| committer | Anton Kling <anton@kling.gg> | 2023-11-08 15:33:11 +0100 |
| commit | d88e7c2124ccb655945bcfd9c2b1cb875a42637d (patch) | |
| tree | ccea3c2efa7664e5c7de040daea3e07e52908fe4 /kernel/arch/i386/boot.s | |
| parent | 2753031a63117fd9de2d189d6731b4de8dd94769 (diff) | |
Kernel/MMU: Create a seperate table for heap allocation
Diffstat (limited to 'kernel/arch/i386/boot.s')
| -rw-r--r-- | kernel/arch/i386/boot.s | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/kernel/arch/i386/boot.s b/kernel/arch/i386/boot.s index 61bbfbb..3286a57 100644 --- a/kernel/arch/i386/boot.s +++ b/kernel/arch/i386/boot.s @@ -34,6 +34,8 @@ boot_page_directory: .skip 4096 boot_page_table1: .skip 4096 +heap_table: + .skip 4096 .section .multiboot.text, "a" .global _start @@ -55,8 +57,8 @@ _start: # If we are past the kernel jump to the final stage # "label 3" - cmpl $(_kernel_end - 0xC0000000), %esi - jge 3f + cmpl $(_kernel_end- 0xC0000000), %esi + jge heap_start 2: # Add permission to the pages @@ -71,10 +73,30 @@ _start: # Loop to the next entry if we haven't finished. loop 1b -3: +heap_start: + # edi contains the buffer we wish to modify + movl $(heap_table - 0xC0000000), %edi + + # for loop + movl $1024, %ecx + addl $4096, %esi +heap: + movl %esi, %edx + orl $0x003, %edx + movl %edx, (%edi) + + # Size of page is 4096 bytes. + addl $4096, %esi + # Size of entries is 4 bytes. + addl $4, %edi + + loop heap + +final: # Map the page table to both virtual addresses 0x00000000 and 0xC0000000. movl $(boot_page_table1 - 0xC0000000 + 0x003), boot_page_directory - 0xC0000000 + 0 movl $(boot_page_table1 - 0xC0000000 + 0x003), boot_page_directory - 0xC0000000 + 768 * 4 + movl $(heap_table - 0xC0000000 + 0x003), boot_page_directory - 0xC0000000 + 769 * 4 # Set cr3 to the address of the boot_page_directory. movl $(boot_page_directory - 0xC0000000), %ecx |