[PATCH 8/8] x86: put 64bit bzImage high

[Yinghai Lu]

also need to make sure pass right 64bit start address to go there directly later.

Signed-off-by: Yinghai Lu <yinghai at kernel.org>
---
 kexec/arch/i386/kexec-bzImage.c |   53 ++++++++++++++++++++++++++++++++++++--
 1 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/kexec/arch/i386/kexec-bzImage.c b/kexec/arch/i386/kexec-bzImage.c
index 6998587..3e705ca 100644
--- a/kexec/arch/i386/kexec-bzImage.c
+++ b/kexec/arch/i386/kexec-bzImage.c
@@ -18,8 +18,10 @@
  */
 
 #define _GNU_SOURCE
+#include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <sys/types.h>
@@ -35,6 +37,7 @@
 #include "../../kexec-elf.h"
 #include "../../kexec-syscall.h"
 #include "kexec-x86.h"
+#include "../x86_64/kexec-x86_64.h"
 #include "x86-linux-setup.h"
 #include "crashdump-x86.h"
 #include <arch/options.h>
@@ -111,12 +114,15 @@ int do_bzImage_load(struct kexec_info *info,
 	size_t size;
 	int kern16_size;
 	unsigned long setup_base, setup_size;
+	struct entry64_regs regs64;
 	struct entry32_regs regs32;
 	struct entry16_regs regs16;
 	unsigned int relocatable_kernel = 0;
 	unsigned long kernel32_load_addr;
 	char *modified_cmdline;
 	unsigned long cmdline_end;
+	unsigned long code64_start_offset = 0;
+	unsigned long kernel64_load_addr = 0;
 
 	/*
 	 * Find out about the file I am about to load.
@@ -154,6 +160,13 @@ int do_bzImage_load(struct kexec_info *info,
 		dbgprintf("bzImage is relocatable\n");
 	}
 
+	if (setup_header.protocol_version >= 0x020C) {
+		code64_start_offset = setup_header.code64_start_offset;
+		if (code64_start_offset)
+			dbgprintf("code64_start_offset: 0x%lx\n",
+					 code64_start_offset);
+	}
+
 	/* Can't use bzImage for crash dump purposes with real mode entry */
 	if((info->kexec_flags & KEXEC_ON_CRASH) && real_mode_entry) {
 		fprintf(stderr, "Can't use bzImage for crash dump purposes"
@@ -250,7 +263,26 @@ int do_bzImage_load(struct kexec_info *info,
 				kernel32_max_addr = real_mode->initrd_addr_max;
 		}
 
-		kernel32_load_addr = add_buffer(info, kernel + kern16_size,
+		if (!real_mode_entry && code64_start_offset) {
+			/* align to 1G to avoid cross the PUD_SIZE boundary */
+			kernel64_load_addr = add_buffer(
+						info, kernel + kern16_size,
+						size, size, 1UL<<30,
+						1UL<<32, ULONG_MAX,
+						-1);
+			if (!kernel64_load_addr)
+				kernel64_load_addr = add_buffer(
+						info, kernel + kern16_size,
+						size, size, 1UL<<30,
+						1UL<<30, 1UL<<32,
+						-1);
+			if (kernel64_load_addr)
+				kernel64_load_addr += code64_start_offset;
+		}
+
+		if (!kernel64_load_addr)
+			kernel32_load_addr = add_buffer(
+						info, kernel + kern16_size,
 						size, size, kern_align,
 						0x100000, kernel32_max_addr,
 						1);
@@ -260,8 +292,11 @@ int do_bzImage_load(struct kexec_info *info,
 		add_segment(info, kernel + kern16_size, size,
 				kernel32_load_addr, size);
 	}
-		
-	dbgprintf("Loaded 32bit kernel at 0x%lx\n", kernel32_load_addr);
+
+	if (kernel64_load_addr)
+		dbgprintf("Loaded 64bit kernel at 0x%lx\n", kernel64_load_addr);
+	else
+		dbgprintf("Loaded 32bit kernel at 0x%lx\n", kernel32_load_addr);
 
 	/* Tell the kernel what is going on */
 	setup_linux_bootloader_parameters(info, real_mode, setup_base,
@@ -271,6 +306,16 @@ int do_bzImage_load(struct kexec_info *info,
 	/* Get the initial register values */
 	elf_rel_get_symbol(&info->rhdr, "entry16_regs", &regs16, sizeof(regs16));
 	elf_rel_get_symbol(&info->rhdr, "entry32_regs", &regs32, sizeof(regs32));
+	if (kernel64_load_addr) {
+		elf_rel_get_symbol(&info->rhdr, "entry64_regs", &regs64, sizeof(regs64));
+		regs64.rbx = 0;           /* Bootstrap processor */
+		regs64.rsi = setup_base;  /* Pointer to the parameters */
+		regs64.rip = kernel64_load_addr; /* the entry point */
+		regs64.rsp = elf_rel_get_addr(&info->rhdr, "stack_end"); /* Stack, unused */
+		elf_rel_set_symbol(&info->rhdr, "entry64_regs", &regs64, sizeof(regs64));
+
+		goto cmd_line;
+	}
 	/*
 
 	 * Initialize the 32bit start information.
@@ -320,6 +365,8 @@ int do_bzImage_load(struct kexec_info *info,
 	elf_rel_set_symbol(&info->rhdr, "entry16_regs", &regs16, sizeof(regs16));
 	elf_rel_set_symbol(&info->rhdr, "entry16_debug_regs", &regs16, sizeof(regs16));
 	elf_rel_set_symbol(&info->rhdr, "entry32_regs", &regs32, sizeof(regs32));
+
+cmd_line:
 	cmdline_end = setup_base + kern16_size + command_line_len - 1;
 	elf_rel_set_symbol(&info->rhdr, "cmdline_end", &cmdline_end,
 			   sizeof(unsigned long));
-- 
1.7.7