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authorRusty Russell <rusty@rustcorp.com.au>2011-07-22 14:39:50 +0930
committerRusty Russell <rusty@rustcorp.com.au>2011-07-22 14:39:50 +0930
commit9f54288def3f92b7805eb6d4b1ddcd73ecf6e889 (patch)
treebb46242a92e47112c2967354b3be0c6daecae7a7 /arch/x86/lguest/i386_head.S
parent3c3ed482dc077a67903a58c9e1aedba1bb18c18a (diff)
lguest: update comments
Also removes a long-unused #define and an extraneous semicolon. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'arch/x86/lguest/i386_head.S')
-rw-r--r--arch/x86/lguest/i386_head.S18
1 files changed, 11 insertions, 7 deletions
diff --git a/arch/x86/lguest/i386_head.S b/arch/x86/lguest/i386_head.S
index c8c95e575c1e..cfa23e37ec5c 100644
--- a/arch/x86/lguest/i386_head.S
+++ b/arch/x86/lguest/i386_head.S
@@ -6,18 +6,22 @@
#include <asm/processor-flags.h>
/*G:020
- * Our story starts with the kernel booting into startup_32 in
- * arch/x86/kernel/head_32.S. It expects a boot header, which is created by
- * the bootloader (the Launcher in our case).
+
+ * Our story starts with the bzImage: booting starts at startup_32 in
+ * arch/x86/boot/compressed/head_32.S. This merely uncompresses the real
+ * kernel in place and then jumps into it: startup_32 in
+ * arch/x86/kernel/head_32.S. Both routines expects a boot header in the %esi
+ * register, which is created by the bootloader (the Launcher in our case).
*
* The startup_32 function does very little: it clears the uninitialized global
* C variables which we expect to be zero (ie. BSS) and then copies the boot
- * header and kernel command line somewhere safe. Finally it checks the
- * 'hardware_subarch' field. This was introduced in 2.6.24 for lguest and Xen:
- * if it's set to '1' (lguest's assigned number), then it calls us here.
+ * header and kernel command line somewhere safe, and populates some initial
+ * page tables. Finally it checks the 'hardware_subarch' field. This was
+ * introduced in 2.6.24 for lguest and Xen: if it's set to '1' (lguest's
+ * assigned number), then it calls us here.
*
* WARNING: be very careful here! We're running at addresses equal to physical
- * addesses (around 0), not above PAGE_OFFSET as most code expectes
+ * addesses (around 0), not above PAGE_OFFSET as most code expects
* (eg. 0xC0000000). Jumps are relative, so they're OK, but we can't touch any
* data without remembering to subtract __PAGE_OFFSET!
*