diff options
| author | Jean-Baptiste Boric <jblbeurope@gmail.com> | 2021-01-18 20:24:25 +0100 |
|---|---|---|
| committer | Andreas Kling <kling@serenityos.org> | 2021-01-19 09:03:37 +0100 |
| commit | 6677ab1ccd2c9f677782ff131889dab890fe53b0 (patch) | |
| tree | b4212b4d883f10fb04f99fd2c3a8c0ee241f12b8 /Kernel/Arch | |
| parent | cb29dca0293fd4c054d5b0fc7b717dbd37005f61 (diff) | |
| download | serenity-6677ab1ccd2c9f677782ff131889dab890fe53b0.zip | |
Boot: Fix undefined Multiboot behaviors
Both ESP and GDTR are left undefined by the Multiboot specification and
OS images must not rely on these values to be valid. Fix the undefined
behaviors so that booting with PXELINUX does not triple-fault the CPU.
Diffstat (limited to 'Kernel/Arch')
| -rw-r--r-- | Kernel/Arch/i386/Boot/boot.S | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Kernel/Arch/i386/Boot/boot.S b/Kernel/Arch/i386/Boot/boot.S index 4fce416868..d0ced81de4 100644 --- a/Kernel/Arch/i386/Boot/boot.S +++ b/Kernel/Arch/i386/Boot/boot.S @@ -194,10 +194,13 @@ start: orl $0x80000000, %eax movl %eax, %cr0 + /* set up stack */ + mov $stack_top, %esp + and $-16, %esp + /* jmp to an address above the 3GB mark */ - push %cs - push $1f - retf + movl $1f,%eax + jmp *%eax 1: movl %cr3, %eax movl %eax, %cr3 @@ -212,10 +215,7 @@ start: addl $8, %edi loop 1b - /* set up initial stack and jump into C++ land */ - mov $stack_top, %esp - and $-16, %esp - + /* jump into C++ land */ addl $0xc0000000, %ebx movl %ebx, multiboot_info_ptr |