[PATCH v4 3/4] Add efi_info in x86 setup header

[Dave Young]

For supporting efi runtime on kexec kernel we need to
fill the efi_info struct in setup_header. I just get
the info in kernel exported boot_params data in debugfs.

v1->v2:
update comment for offset of reserved4_1[] in x87_linux_param_header
Address comment from mjg59: do not break old kernel when use newer kexec-tools.
  add checking for xloadflags bit 4 XLF_EFI_KEXEC. Only fill
  efi_info and pass acpi_rsdp when the kexec kernel support efi boot.
coding style fix, change internal function to be static

Signed-off-by: Dave Young <dyoung at redhat.com>
---
 include/x86/x86-linux.h             | 3 ++-
 kexec/arch/i386/crashdump-x86.c     | 4 +++-
 kexec/arch/i386/x86-linux-setup.c   | 9 +++++++++
 kexec/arch/i386/x86-linux-setup.h   | 1 +
 kexec/arch/x86_64/kexec-bzImage64.c | 6 ++++++
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/x86/x86-linux.h b/include/x86/x86-linux.h
index c41e5f2..50c7324 100644
--- a/include/x86/x86-linux.h
+++ b/include/x86/x86-linux.h
@@ -113,7 +113,8 @@ struct x86_linux_param_header {
 	uint32_t ext_ramdisk_image;		/* 0xc0 */
 	uint32_t ext_ramdisk_size;		/* 0xc4 */
 	uint32_t ext_cmd_line_ptr;		/* 0xc8 */
-	uint8_t reserved4_1[0x1e0 - 0xcc];	/* 0xcc */
+	uint8_t reserved4_1[0x1c0 - 0xcc];	/* 0xe4 */
+	uint8_t efi_info[32];			/* 0x1c0 */
 	uint32_t alt_mem_k;			/* 0x1e0 */
 	uint8_t  reserved5[4];			/* 0x1e4 */
 	uint8_t  e820_map_nr;			/* 0x1e8 */
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index ca98165..53bd077 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -41,6 +41,7 @@
 #include "../../crashdump.h"
 #include "kexec-x86.h"
 #include "crashdump-x86.h"
+#include "x86-linux-setup.h"
 
 #ifdef HAVE_LIBXENCTRL
 #include <xenctrl.h>
@@ -935,7 +936,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
 		return -1;
 	cmdline_add_memmap(mod_cmdline, memmap_p);
-	cmdline_add_efi(mod_cmdline);
+	if (!bzImage_support_efi_boot)
+		cmdline_add_efi(mod_cmdline);
 	cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
 
 	/* Inform second kernel about the presence of ACPI tables. */
diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
index 7b4c65d..38bd9dd 100644
--- a/kexec/arch/i386/x86-linux-setup.c
+++ b/kexec/arch/i386/x86-linux-setup.c
@@ -480,6 +480,13 @@ void setup_subarch(struct x86_linux_param_header *real_mode)
 	get_bootparam(&real_mode->hardware_subarch, offset, sizeof(uint32_t));
 }
 
+static void setup_efi_info(struct x86_linux_param_header *real_mode)
+{
+	off_t offset = offsetof(typeof(*real_mode), efi_info);
+
+	get_bootparam(&real_mode->efi_info, offset, 32);
+}
+
 void setup_linux_system_parameters(struct kexec_info *info,
 				   struct x86_linux_param_header *real_mode)
 {
@@ -489,6 +496,8 @@ void setup_linux_system_parameters(struct kexec_info *info,
 
 	/* get subarch from running kernel */
 	setup_subarch(real_mode);
+	if (bzImage_support_efi_boot)
+		setup_efi_info(real_mode);
 	
 	/* Default screen size */
 	real_mode->orig_x = 0;
diff --git a/kexec/arch/i386/x86-linux-setup.h b/kexec/arch/i386/x86-linux-setup.h
index 2afe97c..6fb84b4 100644
--- a/kexec/arch/i386/x86-linux-setup.h
+++ b/kexec/arch/i386/x86-linux-setup.h
@@ -29,5 +29,6 @@ void setup_linux_system_parameters(struct kexec_info *info,
 
 /* command line parameter may be appended by purgatory */
 #define PURGATORY_CMDLINE_SIZE 64
+extern int bzImage_support_efi_boot;
 
 #endif /* X86_LINUX_SETUP_H */
diff --git a/kexec/arch/x86_64/kexec-bzImage64.c b/kexec/arch/x86_64/kexec-bzImage64.c
index a7b9f15..1983bcf 100644
--- a/kexec/arch/x86_64/kexec-bzImage64.c
+++ b/kexec/arch/x86_64/kexec-bzImage64.c
@@ -42,6 +42,7 @@
 #include <arch/options.h>
 
 static const int probe_debug = 0;
+int bzImage_support_efi_boot;
 
 int bzImage64_probe(const char *buf, off_t len)
 {
@@ -82,6 +83,11 @@ int bzImage64_probe(const char *buf, off_t len)
 		/* Must be KERNEL_64 and CAN_BE_LOADED_ABOVE_4G */
 		return -1;
 	}
+
+#define XLF_EFI_KEXEC   (1 << 4)
+	if ((header->xloadflags & XLF_EFI_KEXEC) == XLF_EFI_KEXEC)
+		bzImage_support_efi_boot = 1;
+
 	/* I've got a relocatable bzImage64 */
 	if (probe_debug)
 		fprintf(stderr, "It's a relocatable bzImage64\n");
-- 
1.8.3.1