---

yaml
---
r: 72275
b: refs/heads/master
c: 814a0e5
h: refs/heads/master
i:
  72273: 0b7310f
  72271: e136d95
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1f5a29022ac66bc90cbe2a2162f56e9cd7b393ef
+refs/heads/master: 814a0e5cdfbd384f4bf7a8443f9c3b885f413d58

trunk/Documentation/lguest/lguest.c

@@ -251,23 +251,6 @@ static void *get_pages(unsigned int num)
 	return addr;
 }
 
-/* To find out where to start we look for the magic Guest string, which marks
- * the code we see in lguest_asm.S.  This is a hack which we are currently
- * plotting to replace with the normal Linux entry point. */
-static unsigned long entry_point(const void *start, const void *end)
-{
-	const void *p;
-
-	/* The scan gives us the physical starting address.  We boot with
-	 * pagetables set up with virtual and physical the same, so that's
-	 * OK. */
-	for (p = start; p < end; p++)
-		if (memcmp(p, "GenuineLguest", strlen("GenuineLguest")) == 0)
-			return to_guest_phys(p + strlen("GenuineLguest"));
-
-	errx(1, "Is this image a genuine lguest?");
-}
-
 /* This routine is used to load the kernel or initrd.  It tries mmap, but if
  * that fails (Plan 9's kernel file isn't nicely aligned on page boundaries),
  * it falls back to reading the memory in. */
@@ -303,7 +286,6 @@ static void map_at(int fd, void *addr, unsigned long offset, unsigned long len)
  * We return the starting address. */
 static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr)
 {
-	void *start = (void *)-1, *end = NULL;
 	Elf32_Phdr phdr[ehdr->e_phnum];
 	unsigned int i;
 
@@ -335,19 +317,13 @@ static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr)
 		verbose("Section %i: size %i addr %p\n",
 			i, phdr[i].p_memsz, (void *)phdr[i].p_paddr);
 
-		/* We track the first and last address we mapped, so we can
-		 * tell entry_point() where to scan. */
-		if (from_guest_phys(phdr[i].p_paddr) < start)
-			start = from_guest_phys(phdr[i].p_paddr);
-		if (from_guest_phys(phdr[i].p_paddr) + phdr[i].p_filesz > end)
-			end=from_guest_phys(phdr[i].p_paddr)+phdr[i].p_filesz;
-
 		/* We map this section of the file at its physical address. */
 		map_at(elf_fd, from_guest_phys(phdr[i].p_paddr),
 		       phdr[i].p_offset, phdr[i].p_filesz);
 	}
 
-	return entry_point(start, end);
+	/* The entry point is given in the ELF header. */
+	return ehdr->e_entry;
 }
 
 /*L:160 Unfortunately the entire ELF image isn't compressed: the segments
@@ -374,7 +350,8 @@ static unsigned long unpack_bzimage(int fd)
 
 	verbose("Unpacked size %i addr %p\n", len, img);
 
-	return entry_point(img, img + len);
+	/* The entry point for a bzImage is always the first byte */
+	return (unsigned long)img;
 }
 
 /*L:150 A bzImage, unlike an ELF file, is not meant to be loaded.  You're
@@ -1684,8 +1661,15 @@ int main(int argc, char *argv[])
 	*(u32 *)(boot + 0x228) = 4096;
 	concat(boot + 4096, argv+optind+2);
 
-	/* The guest type value of "1" tells the Guest it's under lguest. */
-	*(int *)(boot + 0x23c) = 1;
+	/* Boot protocol version: 2.07 supports the fields for lguest. */
+	*(u16 *)(boot + 0x206) = 0x207;
+
+	/* The hardware_subarch value of "1" tells the Guest it's an lguest. */
+	*(u32 *)(boot + 0x23c) = 1;
+
+	/* Set bit 6 of the loadflags (aka. KEEP_SEGMENTS) so the entry path
+	 * does not try to reload segment registers. */
+	*(u8 *)(boot + 0x211) |= (1 << 6);
 
 	/* We tell the kernel to initialize the Guest: this returns the open
 	 * /dev/lguest file descriptor. */

trunk/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. */

trunk/arch/x86/lguest/i386_head.S

@@ -5,11 +5,8 @@
 #include <asm/thread_info.h>
 #include <asm/processor-flags.h>
 
-/*G:020 This is where we begin: we have a magic signature which the launcher
- * looks for.  The plan is that the Linux boot protocol will be extended with a
- * "platform type" field which will guide us here from the normal entry point,
- * but for the moment this suffices.  The normal boot code uses %esi for the
- * boot header, so we do too.
+/*G:020 This is where we begin: head.S notes that the boot header's platform
+ * type field is "1" (lguest), so calls us here.  The boot header is in %esi.
  *
  * WARNING: be very careful here!  We're running at addresses equal to physical
  * addesses (around 0), not above PAGE_OFFSET as most code expectes
@@ -19,19 +16,14 @@
  * The .section line puts this code in .init.text so it will be discarded after
  * boot. */
 .section .init.text, "ax", @progbits
-.ascii "GenuineLguest"
+ENTRY(lguest_entry)
 	/* Make initial hypercall now, so we can set up the pagetables. */
 	movl $LHCALL_LGUEST_INIT, %eax
 	movl $lguest_data - __PAGE_OFFSET, %edx
 	int $LGUEST_TRAP_ENTRY
 
-	/* Set up boot information pointer to hand to lguest_init(): it wants
-	 * a virtual address. */
-	movl %esi, %eax
-	addl $__PAGE_OFFSET, %eax
-
 	/* The Host put the toplevel pagetable in lguest_data.pgdir.  The movsl
-	 * instruction uses %esi, so we needed to save it above. */
+	 * instruction uses %esi implicitly. */
 	movl lguest_data - __PAGE_OFFSET + LGUEST_DATA_pgdir, %esi
 
 	/* Copy first 32 entries of page directory to __PAGE_OFFSET entries.
@@ -47,7 +39,6 @@
 	/* Set up the initial stack so we can run C code. */
 	movl $(init_thread_union+THREAD_SIZE),%esp
 
-
 	/* Jumps are relative, and we're running __PAGE_OFFSET too low at the
 	 * moment. */
 	jmp lguest_init+__PAGE_OFFSET