makefile: add i686/arch.a target

1 files changed, 42 insertions, 0 deletions

diff --git a/i686/init.s b/i686/init.s
new file mode 100644
index 0000000..92710df
--- /dev/null
+++ b/i686/init.s
@@ -0,0 +1,42 @@
+.section .stack, "aw", @nobits
+.global k_stack
+.align 16       /* Stack on x86 must be 16-byte aligned according to System V ABI */
+k_stack_bottom:
+    .skip 16 * 1024     /* 16 kByte */
+k_stack:
+
+.section .pages, "aw", @nobits
+.align 4096
+.global k_pagedir
+k_pagedir:      .skip 1024 * 4
+.global k_ptable0x300
+k_ptable0x300: .skip 1024 * 4
+
+.section .text
+.global k_init
+.extern kmain
+k_init:
+    # kernel entry point, higher half
+
+    # unmap the identity mapping as its no longer necessary
+    movl $0, k_pagedir + 0 * 4
+    mov %cr3, %ecx              # reload cr3 to force a TLB flush
+    mov %ecx, %cr3
+
+    # zero out the stack
+    mov  $4096, %ecx # loop counter
+    mov  $k_stack_bottom, %edi  # start from the bottom
+    xor  %edx, %edx             # clear %edx
+1:  movl %edx, (%edi)           # store %edx into address in %edi
+    addl $4, %edi               # point to next address
+    loop 1b                     # loop according to %ecx
+
+    mov   $k_stack, %esp        # point stack pointer to the stack
+
+    call kmain
+
+    /* If the system has nothing more to do, put it in an infinite loop */
+    cli         # disable interrupts
+h:  hlt         # wait for interrupt
+    jmp h       # continue waiting for interrupt
+