@@ -82,6 +82,13 @@ multiboot2_header_start:
/* Align modules at page boundry. */
mb2ht_init MB2_HT(MODULE_ALIGN), MB2_HT(REQUIRED)
+ /* Load address preference. */
+ mb2ht_init MB2_HT(RELOCATABLE), MB2_HT(OPTIONAL), \
+ sym_offset(start), /* Min load address. */ \
+ 0xffffffff, /* The end of image max load address (4 GiB - 1). */ \
+ 0x200000, /* Load address alignment (2 MiB). */ \
+ MULTIBOOT2_LOAD_PREFERENCE_HIGH
+
/* Console flags tag. */
mb2ht_init MB2_HT(CONSOLE_FLAGS), MB2_HT(OPTIONAL), \
MULTIBOOT2_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED
@@ -372,10 +379,19 @@ __start:
cmp %edi,MB2_fixed_total_size(%ebx)
jbe trampoline_bios_setup
+ /* Get Xen image load base address from Multiboot2 information. */
+ cmpl $MULTIBOOT2_TAG_TYPE_LOAD_BASE_ADDR,MB2_tag_type(%ecx)
+ jne 1f
+
+ mov MB2_load_base_addr(%ecx),%esi
+ sub $XEN_IMG_OFFSET,%esi
+ jmp 9f
+
+1:
/* Get mem_lower from Multiboot2 information. */
cmpl $MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO,MB2_tag_type(%ecx)
cmove MB2_mem_lower(%ecx),%edx
- je trampoline_bios_setup
+ je 9f
/* EFI IA-32 platforms are not supported. */
cmpl $MULTIBOOT2_TAG_TYPE_EFI32,MB2_tag_type(%ecx)
@@ -389,6 +405,7 @@ __start:
cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%ecx)
je trampoline_bios_setup
+9:
/* Go to next Multiboot2 information tag. */
add MB2_tag_size(%ecx),%ecx
add $(MULTIBOOT2_TAG_ALIGN-1),%ecx
@@ -175,6 +175,7 @@ void __dummy__(void)
OFFSET(MB2_fixed_total_size, multiboot2_fixed_t, total_size);
OFFSET(MB2_tag_type, multiboot2_tag_t, type);
OFFSET(MB2_tag_size, multiboot2_tag_t, size);
+ OFFSET(MB2_load_base_addr, multiboot2_tag_load_base_addr_t, load_base_addr);
OFFSET(MB2_mem_lower, multiboot2_tag_basic_meminfo_t, mem_lower);
OFFSET(MB2_efi64_st, multiboot2_tag_efi64_t, pointer);
OFFSET(MB2_efi64_ih, multiboot2_tag_efi64_ih_t, pointer);
@@ -59,11 +59,17 @@
#define MULTIBOOT2_HEADER_TAG_EFI_BS 7
#define MULTIBOOT2_HEADER_TAG_ENTRY_ADDRESS_EFI32 8
#define MULTIBOOT2_HEADER_TAG_ENTRY_ADDRESS_EFI64 9
+#define MULTIBOOT2_HEADER_TAG_RELOCATABLE 10
/* Header tag flags. */
#define MULTIBOOT2_HEADER_TAG_REQUIRED 0
#define MULTIBOOT2_HEADER_TAG_OPTIONAL 1
+/* Where image should be loaded (suggestion not requirement). */
+#define MULTIBOOT2_LOAD_PREFERENCE_NONE 0
+#define MULTIBOOT2_LOAD_PREFERENCE_LOW 1
+#define MULTIBOOT2_LOAD_PREFERENCE_HIGH 2
+
/* Header console tag console_flags. */
#define MULTIBOOT2_CONSOLE_FLAGS_CONSOLE_REQUIRED 1
#define MULTIBOOT2_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED 2
@@ -90,6 +96,7 @@
#define MULTIBOOT2_TAG_TYPE_EFI_BS 18
#define MULTIBOOT2_TAG_TYPE_EFI32_IH 19
#define MULTIBOOT2_TAG_TYPE_EFI64_IH 20
+#define MULTIBOOT2_TAG_TYPE_LOAD_BASE_ADDR 21
/* Multiboot 2 tag alignment. */
#define MULTIBOOT2_TAG_ALIGN 8
@@ -120,6 +127,12 @@ typedef struct {
typedef struct {
u32 type;
u32 size;
+ u32 load_base_addr;
+} multiboot2_tag_load_base_addr_t;
+
+typedef struct {
+ u32 type;
+ u32 size;
char string[0];
} multiboot2_tag_string_t;
Add multiboot2 protocol support for relocatable images. Only GRUB2 with "multiboot2: Add support for relocatable images" patch understands that feature. Older multiboot protocol (regardless of version) compatible loaders ignore it and everything works as usual. Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> --- v4 - suggestions/fixes: - do not get Xen image load base address from multiboot2 information in x86_64 code (suggested by Jan Beulich), - improve label names (suggested by Jan Beulich), - improve comments, (suggested by Jan Beulich). v3 - suggestions/fixes: - use %esi and %r15d instead of %ebp to store Xen image load base address, - rename some types and constants, - reformat xen/include/xen/multiboot2.h (suggested by Konrad Rzeszutek Wilk), - improve comments, - improve commit message (suggested by Konrad Rzeszutek Wilk). --- xen/arch/x86/boot/head.S | 19 ++++++++++++++++++- xen/arch/x86/x86_64/asm-offsets.c | 1 + xen/include/xen/multiboot2.h | 13 +++++++++++++ 3 files changed, 32 insertions(+), 1 deletion(-)