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author | Rusty Russell <rusty@rustcorp.com.au> | 2011-07-22 14:39:50 +0930 |
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committer | Rusty Russell <rusty@rustcorp.com.au> | 2011-07-22 14:39:50 +0930 |
commit | 9f54288def3f92b7805eb6d4b1ddcd73ecf6e889 (patch) | |
tree | bb46242a92e47112c2967354b3be0c6daecae7a7 /arch/x86/lguest/i386_head.S | |
parent | 3c3ed482dc077a67903a58c9e1aedba1bb18c18a (diff) | |
download | linux-9f54288def3f92b7805eb6d4b1ddcd73ecf6e889.tar.bz2 |
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.S | 18 |
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! * |