Revert lguest magic and use hook in head.S

Version 2.07 of the boot protocol uses 0x23C for the hardware_subarch
field, that for lguest is "1".  This allows us to use the standard
boot entry point rather than the "GenuineLguest" string hack.

The standard entry point also clears the BSS and copies the boot parameters
and commandline for us, saving more code.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 1 insertions, 16 deletions

diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 495e46a1f111..d2235db4085f 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -928,18 +928,8 @@ static unsigned lguest_patch(u8 type, u16 clobber, void *ibuf,
 /*G:030 Once we get to lguest_init(), we know we're a Guest.  The pv_ops
  * structures in the kernel provide points for (almost) every routine we have
  * to override to avoid privileged instructions. */
-__init void lguest_init(void *boot)
+__init void lguest_init(void)
 {
-        /* Copy boot parameters first: the Launcher put the physical location
-         * in %esi, and head.S converted that to a virtual address and handed
-         * it to us.  We use "__memcpy" because "memcpy" sometimes tries to do
-         * tricky things to go faster, and we're not ready for that. */
-        __memcpy(&boot_params, boot, PARAM_SIZE);
-        /* The boot parameters also tell us where the command-line is: save
-         * that, too. */
-        __memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr),
-               COMMAND_LINE_SIZE);
-
         /* We're under lguest, paravirt is enabled, and we're running at
          * privilege level 1, not 0 as normal. */
         pv_info.name = "lguest";
@@ -1024,11 +1014,6 @@ __init void lguest_init(void *boot)
          * the normal data segment to get through booting. */
         asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory");
 
-        /* Clear the part of the kernel data which is expected to be zero.
-         * Normally it will be anyway, but if we're loading from a bzImage with
-         * CONFIG_RELOCATALE=y, the relocations will be sitting here. */
-        memset(__bss_start, 0, __bss_stop - __bss_start);
-
         /* The Host uses the top of the Guest's virtual address space for the
          * Host<->Guest Switcher, and it tells us how much it needs in
          * lguest_data.reserve_mem, set up on the LGUEST_INIT hypercall. */