diff options
Diffstat (limited to 'asm/start.s')
| -rw-r--r-- | asm/start.s | 87 |
1 files changed, 0 insertions, 87 deletions
diff --git a/asm/start.s b/asm/start.s deleted file mode 100644 index ca99c20..0000000 --- a/asm/start.s +++ /dev/null @@ -1,87 +0,0 @@ -.global _start -.global _start_smp -.global stack_top -.global stack_bottom - -# Fill Multiboot Haeder, init stack and call kernel_main passing two params: -# eax - magic number -# ebx - multiboot structure - -# Declare constants used for creating a multiboot header. -.set ALIGN, 1<<0 # align loaded modules on page boundaries -.set MEMINFO, 1<<1 # provide memory map -.set GFXINFO, 1<<2 # provide gfx info -.set FLAGS, ALIGN | MEMINFO | GFXINFO # this is the Multiboot 'flag' field -.set MAGIC, 0x1BADB002 # 'magic number' lets bootloader find the header -.set CHECKSUM, -(MAGIC + FLAGS) # checksum of above, to prove we are multiboot - -# entry point for application processors we will copy this to 0x7000 later - -.section .smp -.code16 -_start_smp: -call smp_start # TODO: align later before going C - - -# Declare a header as in the Multiboot Standard. We put this into a special -# section so we can force the header to be in the start of the final program. -# You don't need to understand all these details as it is just magic values that -# is documented in the multiboot standard. The bootloader will search for this -# magic sequence and recognize us as a multiboot kernel. - -.section .multiboot -.code32 -.align 4 -.long MAGIC -.long FLAGS -.long CHECKSUM - -.long 0 # we dont need this for ELF -.long 0 -.long 0 -.long 0 -.long 0 - -# we override this from grub anyway -.long 0 #gfx_stuff 0=enable! -.long 640 -.long 480 -.long 32 - -# Currently the stack pointer register (esp) points at anything and using it may -# cause massive harm. Instead, we'll provide our own stack. We will allocate -# room for a small temporary stack by creating a symbol at the bottom of it, -# then allocating 16384 bytes for it, and finally creating a symbol at the top. -.section .bootstrap_stack, "aw", @nobits -stack_bottom: -.skip 16384 # 16 KiB -stack_top: - -# The linker script specifies _start as the entry point to the kernel and the -# bootloader will jump to this position once the kernel has been loaded. It -# doesn't make sense to return from this function as the bootloader is gone. -.section .text - -_start: - - # To set up a stack, we simply set the esp register to point to the top of - # our stack (as it grows downwards). - movl $stack_top, %esp - - sub $8, %esp #to align on 16byte before calling C - push %ebx #pass address of the multiboot information data structure - push %eax #pass eax, so kernel can check for magic number - - call kernel_main - - # turn off interrupts and halt. - # this should never be reached - cli - hlt - -.Lhang: - jmp .Lhang - -# Set the size of the _start symbol to the current location '.' minus its start. -# This is useful when debugging or when you implement call tracing. -.size _start, . - _start |