Initial commit

x86 kernel that prints a hello world message to com1

1 files changed, 25 insertions, 0 deletions

diff --git a/arch/i686/macros.s b/arch/i686/macros.s
new file mode 100644
index 0000000..a9b8b4d
--- /dev/null
+++ b/arch/i686/macros.s
@@ -0,0 +1,25 @@
+.set PAGE_RO, 0x001
+.set PAGE_RW, 0x003
+/* write section to page table macro
+ *
+ * Registers used:
+ * %ecx: loop counter   [ set to $1024 ]
+ * %edx: temporary
+ * %esi: current page being mapped
+ * %edi: page entry     [ set to $page_addr ]
+ */
+.macro mmap_section begin, end, access
+    mov  $\begin, %esi  # from $begin
+1:  cmpl $\end, %esi    # until $end
+    jge  2f
+
+    movl %esi, %edx
+    orl  $\access, %edx
+    movl %edx, (%edi)
+
+    addl $4096, %esi    # move to next page
+    addl $4, %edi       # size of page entry is 4 bytes
+    loop 1b             # loop according to %ecx
+2:
+.endm
+