1 files changed, 137 insertions, 0 deletions
diff --git a/asm/x86.s b/asm/x86.s
new file mode 100644
index 0000000..a5bcb1c
--- /dev/null
+++ b/asm/x86.s
@@ -0,0 +1,137 @@
+// Basic low-level x86 32-bit calls //
+
+// reading and writing ports
+
+.global x86_outb    // 8 bit out
+.global x86_inb     // 8 bit in
+.global x86_outw    // 16 bit out
+.global x86_inw     // 16 bit in
+.global x86_outl    // 32 bit out
+.global x86_inl     // 32 bit in
+
+// interrupts
+
+.global x86_cli    // disable interrupts
+.global x86_sti    // enable interrupts
+
+// xchg
+.global x86_xchg   // exchange (for semaphors etc.)
+
+// invlpg
+.global x86_invlpg // invalidate translation lookaside buffer (tlb)
+
+// control registers
+.global x86_get_cr
+.global x86_set_cr
+
+x86_outb:
+    mov 4(%esp), %edx
+    mov 8(%esp), %eax
+    outb %al,%dx
+    ret
+
+x86_inb:
+    mov 4(%esp), %edx
+    inb %dx,%al
+    ret
+
+x86_outw:
+    mov 4(%esp), %edx
+    mov 8(%esp), %eax
+    outw %ax,%dx
+    ret
+
+x86_inw:
+    mov 4(%esp), %edx
+    inw %dx,%ax
+    ret
+
+x86_outl:
+    mov 4(%esp), %edx
+    mov 8(%esp), %eax
+    outl %eax,%dx
+    ret
+
+x86_inl:
+    mov 4(%esp), %edx
+    inl %dx,%eax
+    ret
+
+x86_cli:
+    cli
+    ret
+
+x86_sti:
+    sti
+    ret
+
+x86_xchg:
+// --   uint8_t result;
+// -- 
+// --   // The + in "+m" denotes a read-modify-write operand.
+// --   asm volatile("lock xchgb %0, %1" :
+// --                "+m" (*addr), "=a" (result) :
+// --                "1" (val) :
+// --                "cc");
+// -- 
+// --   return result;
+// -- } 
+    ret
+
+x86_get_cr:
+    mov 4(%esp), %ecx
+    cmp %ecx,0
+    je get_cr0
+    cmp %ecx,2
+    je get_cr2
+    cmp %ecx,3
+    je get_cr3
+    cmp %ecx,4
+    je get_cr4
+    ret
+
+x86_set_cr:
+    mov 4(%esp), %eax
+    mov 8(%esp), %ecx
+    cmp %ecx,0
+    je set_cr0
+    cmp %ecx,2
+    je set_cr2
+    cmp %ecx,3
+    je set_cr3
+    cmp %ecx,4
+    je set_cr4
+    ret
+
+get_cr0:
+    mov %cr0,%eax
+    ret
+
+get_cr2:
+    mov %cr2,%eax
+    ret
+
+get_cr3:
+    mov %cr3,%eax
+    ret
+
+get_cr4:
+    mov %cr4,%eax
+    ret
+
+set_cr0:
+    mov %eax,%cr0
+    ret
+
+set_cr2:
+    mov %eax,%cr2
+    ret
+
+set_cr3:
+    mov %eax,%cr3
+    ret
+
+set_cr4:
+    mov %eax,%cr4
+    ret
+