Some AP booting debug

21c44a5e · Silas Boyd-Wickizer · 389f0bd5 · 21c44a5e · 21c44a5e
--- a/kernel/bootother.S
+++ b/kernel/bootother.S
@@ -29,8 +29,15 @@
 .code16           
 .globl start
 start:
-        cli
-        cld
+	cli
+	wbinvd
+	mov $0, %ax
+	mov %ax, %ds
+	cld
+
+	# Announce we made it this far.
+	# Useful for debugging in bootothers.
+	movl $0x0a55face, start - 64
        
 	lgdt gdtdesc
 	movl %cr0, %eax

--- a/kernel/main.cc
+++ b/kernel/main.cc
@@ -84,6 +84,8 @@ bootothers(void)
    stack = (char*) ksalloc(slab_stack);
    *(u32*)(code-4) = (u32)v2p(&apstart);
    *(u64*)(code-12) = (u64)stack + KSTACKSIZE;
+    // bootother.S sets this to 0x0a55face early on
+    *(u32*)(code-64) = 0;

    bstate = 0;
    lapicstartap(c->hwid, v2p(code));