@@ -89,6 +89,13 @@ multiboot2_header_start:
0, /* Number of the lines - no preference. */ \
0 /* Number of bits per pixel - no preference. */
+ /* Request that ExitBootServices() not be called. */
+ mb2ht_init MB2_HT(EFI_BS), MB2_HT(OPTIONAL)
+
+ /* EFI64 Multiboot2 entry point. */
+ mb2ht_init MB2_HT(ENTRY_ADDRESS_EFI64), MB2_HT(OPTIONAL), \
+ sym_phys(__efi64_mb2_start)
+
/* Multiboot2 header end tag. */
mb2ht_init MB2_HT(END), MB2_HT(REQUIRED)
.Lmultiboot2_header_end:
@@ -100,20 +107,50 @@ multiboot2_header_start:
gdt_boot_descr:
.word 6*8-1
.long sym_phys(trampoline_gdt)
+ .long 0 /* Needed for 64-bit lgdt */
.Lbad_cpu_msg: .asciz "ERR: Not a 64-bit CPU!"
.Lbad_ldr_msg: .asciz "ERR: Not a Multiboot bootloader!"
+.Lbad_ldr_nbs: .asciz "ERR: Bootloader shutdown EFI x64 boot services!"
+.Lbad_ldr_nst: .asciz "ERR: EFI SystemTable is not provided by bootloader!"
+.Lbad_ldr_nih: .asciz "ERR: EFI ImageHandle is not provided by bootloader!"
+.Lbad_efi_msg: .asciz "ERR: EFI IA-32 platforms are not supported!"
+
+ .section .init.data, "aw", @progbits
+ .align 4
+
+vga_text_buffer:
+ .long 0xb8000
+
+efi_platform:
+ .byte 0
.section .init.text, "ax", @progbits
bad_cpu:
mov $(sym_phys(.Lbad_cpu_msg)),%esi # Error message
- jmp print_err
+ jmp .Lget_vtb
not_multiboot:
mov $(sym_phys(.Lbad_ldr_msg)),%esi # Error message
-print_err:
- mov $0xB8000,%edi # VGA framebuffer
-1: mov (%esi),%bl
+ jmp .Lget_vtb
+.Lmb2_no_st:
+ mov $(sym_phys(.Lbad_ldr_nst)),%esi # Error message
+ jmp .Lget_vtb
+.Lmb2_no_ih:
+ mov $(sym_phys(.Lbad_ldr_nih)),%esi # Error message
+ jmp .Lget_vtb
+.Lmb2_no_bs:
+ mov $(sym_phys(.Lbad_ldr_nbs)),%esi # Error message
+ xor %edi,%edi # No VGA text buffer
+ jmp .Lsend_chr
+.Lmb2_efi_ia_32:
+ mov $(sym_phys(.Lbad_efi_msg)),%esi # Error message
+ xor %edi,%edi # No VGA text buffer
+ jmp .Lsend_chr
+.Lget_vtb:
+ mov sym_phys(vga_text_buffer),%edi
+.Lsend_chr:
+ mov (%esi),%bl
test %bl,%bl # Terminate on '\0' sentinel
je .Lhalt
mov $0x3f8+5,%dx # UART Line Status Register
@@ -123,13 +160,192 @@ print_err:
mov $0x3f8+0,%dx # UART Transmit Holding Register
mov %bl,%al
out %al,%dx # Send a character over the serial line
- movsb # Write a character to the VGA framebuffer
+ test %edi,%edi # Is the VGA text buffer available?
+ jz .Lsend_chr
+ movsb # Write a character to the VGA text buffer
mov $7,%al
- stosb # Write an attribute to the VGA framebuffer
- jmp 1b
+ stosb # Write an attribute to the VGA text buffer
+ jmp .Lsend_chr
.Lhalt: hlt
jmp .Lhalt
+ .code64
+
+__efi64_mb2_start:
+ /*
+ * Multiboot2 spec says that here CPU is in 64-bit mode. However,
+ * there is also guarantee that all code and data is always put
+ * by the bootloader below 4 GiB. Hence, we can safely truncate
+ * addresses to 32-bits in most cases below.
+ */
+
+ cld
+
+ /* VGA is not available on EFI platforms. */
+ movl $0,vga_text_buffer(%rip)
+
+ /* Check for Multiboot2 bootloader. */
+ cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax
+ je .Lefi_multiboot2_proto
+
+ /* Jump to not_multiboot after switching CPU to x86_32 mode. */
+ lea not_multiboot(%rip),%r15
+ jmp x86_32_switch
+
+.Lefi_multiboot2_proto:
+ /* Zero EFI SystemTable and EFI ImageHandle addresses. */
+ xor %esi,%esi
+ xor %edi,%edi
+
+ /* Skip Multiboot2 information fixed part. */
+ lea (MB2_fixed_sizeof+MULTIBOOT2_TAG_ALIGN-1)(%rbx),%ecx
+ and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx
+
+.Lefi_mb2_tsize:
+ /* Check Multiboot2 information total size. */
+ mov %ecx,%r8d
+ sub %ebx,%r8d
+ cmp %r8d,MB2_fixed_total_size(%rbx)
+ jbe .Lrun_bs
+
+ /* Are EFI boot services available? */
+ cmpl $MULTIBOOT2_TAG_TYPE_EFI_BS,MB2_tag_type(%rcx)
+ jne .Lefi_mb2_st
+
+ /* We are on EFI platform and EFI boot services are available. */
+ incb efi_platform(%rip)
+
+ /*
+ * Disable real mode and other legacy stuff which should not
+ * be run on EFI platforms.
+ */
+ incb skip_realmode(%rip)
+ jmp .Lefi_mb2_next_tag
+
+.Lefi_mb2_st:
+ /* Get EFI SystemTable address from Multiboot2 information. */
+ cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%rcx)
+ cmove MB2_efi64_st(%rcx),%rsi
+ je .Lefi_mb2_next_tag
+
+ /* Get EFI ImageHandle address from Multiboot2 information. */
+ cmpl $MULTIBOOT2_TAG_TYPE_EFI64_IH,MB2_tag_type(%rcx)
+ cmove MB2_efi64_ih(%rcx),%rdi
+ je .Lefi_mb2_next_tag
+
+ /* Is it the end of Multiboot2 information? */
+ cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%rcx)
+ je .Lrun_bs
+
+.Lefi_mb2_next_tag:
+ /* Go to next Multiboot2 information tag. */
+ add MB2_tag_size(%rcx),%ecx
+ add $(MULTIBOOT2_TAG_ALIGN-1),%ecx
+ and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx
+ jmp .Lefi_mb2_tsize
+
+.Lrun_bs:
+ /* Are EFI boot services available? */
+ cmpb $0,efi_platform(%rip)
+
+ /* Jump to .Lmb2_no_bs after switching CPU to x86_32 mode. */
+ lea .Lmb2_no_bs(%rip),%r15
+ jz x86_32_switch
+
+ /* Is EFI SystemTable address provided by boot loader? */
+ test %rsi,%rsi
+
+ /* Jump to .Lmb2_no_st after switching CPU to x86_32 mode. */
+ lea .Lmb2_no_st(%rip),%r15
+ jz x86_32_switch
+
+ /* Is EFI ImageHandle address provided by boot loader? */
+ test %rdi,%rdi
+
+ /* Jump to .Lmb2_no_ih after switching CPU to x86_32 mode. */
+ lea .Lmb2_no_ih(%rip),%r15
+ jz x86_32_switch
+
+ /*
+ * Align the stack as UEFI spec requires. Keep it aligned
+ * before efi_multiboot2() call by pushing/popping even
+ * numbers of items on it.
+ */
+ and $~15,%rsp
+
+ /* Save Multiboot2 magic on the stack. */
+ push %rax
+
+ /* Save EFI ImageHandle on the stack. */
+ push %rdi
+
+ /*
+ * Initialize BSS (no nasty surprises!).
+ * It must be done earlier than in BIOS case
+ * because efi_multiboot2() touches it.
+ */
+ lea __bss_start(%rip),%edi
+ lea __bss_end(%rip),%ecx
+ sub %edi,%ecx
+ shr $3,%ecx
+ xor %eax,%eax
+ rep stosq
+
+ /* Keep the stack aligned. Do not pop a single item off it. */
+ mov (%rsp),%rdi
+
+ /*
+ * efi_multiboot2() is called according to System V AMD64 ABI:
+ * - IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable.
+ */
+ call efi_multiboot2
+
+ /* Just pop an item from the stack. */
+ pop %rax
+
+ /* Restore Multiboot2 magic. */
+ pop %rax
+
+ /* Jump to trampoline_setup after switching CPU to x86_32 mode. */
+ lea trampoline_setup(%rip),%r15
+
+x86_32_switch:
+ mov %r15,%rdi
+
+ cli
+
+ /* Initialize GDTR. */
+ lgdt gdt_boot_descr(%rip)
+
+ /* Reload code selector. */
+ pushq $BOOT_CS32
+ lea cs32_switch(%rip),%edx
+ push %rdx
+ lretq
+
+ .code32
+
+cs32_switch:
+ /* Initialize basic data segments. */
+ mov $BOOT_DS,%edx
+ mov %edx,%ds
+ mov %edx,%es
+ mov %edx,%ss
+ /* %esp is initialized later. */
+
+ /* Load null descriptor to unused segment registers. */
+ xor %edx,%edx
+ mov %edx,%fs
+ mov %edx,%gs
+
+ /* Disable paging. */
+ mov %cr0,%edx
+ and $(~X86_CR0_PG),%edx
+ mov %edx,%cr0
+
+ /* Jump to earlier loaded address. */
+ jmp *%edi
+
__start:
cld
cli
@@ -157,7 +373,7 @@ __start:
/* Not available? BDA value will be fine. */
cmovnz MB_mem_lower(%ebx),%edx
- jmp trampoline_setup
+ jmp trampoline_bios_setup
.Lmultiboot2_proto:
/* Skip Multiboot2 information fixed part. */
@@ -169,24 +385,33 @@ __start:
mov %ecx,%edi
sub %ebx,%edi
cmp %edi,MB2_fixed_total_size(%ebx)
- jbe trampoline_setup
+ jbe trampoline_bios_setup
/* Get mem_lower from Multiboot2 information. */
cmpl $MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO,MB2_tag_type(%ecx)
cmove MB2_mem_lower(%ecx),%edx
- je trampoline_setup
+ je .Lmb2_next_tag
+
+ /* EFI IA-32 platforms are not supported. */
+ cmpl $MULTIBOOT2_TAG_TYPE_EFI32,MB2_tag_type(%ecx)
+ je .Lmb2_efi_ia_32
+
+ /* Bootloader shutdown EFI x64 boot services. */
+ cmpl $MULTIBOOT2_TAG_TYPE_EFI64,MB2_tag_type(%ecx)
+ je .Lmb2_no_bs
/* Is it the end of Multiboot2 information? */
cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%ecx)
- je trampoline_setup
+ je trampoline_bios_setup
+.Lmb2_next_tag:
/* Go to next Multiboot2 information tag. */
add MB2_tag_size(%ecx),%ecx
add $(MULTIBOOT2_TAG_ALIGN-1),%ecx
and $~(MULTIBOOT2_TAG_ALIGN-1),%ecx
jmp .Lmb2_tsize
-trampoline_setup:
+trampoline_bios_setup:
/* Set up trampoline segment 64k below EBDA */
movzwl 0x40e,%ecx /* EBDA segment */
cmp $0xa000,%ecx /* sanity check (high) */
@@ -207,23 +432,54 @@ trampoline_setup:
cmp %ecx,%edx /* compare with BDA value */
cmovb %edx,%ecx /* and use the smaller */
-2: /* Reserve 64kb for the trampoline */
- sub $0x1000,%ecx
+2:
+ /* Reserve memory for the trampoline and the low-memory stack. */
+ sub $((TRAMPOLINE_SPACE+TRAMPOLINE_STACK_SPACE)>>4),%ecx
/* From arch/x86/smpboot.c: start_eip had better be page-aligned! */
xor %cl, %cl
shl $4, %ecx
mov %ecx,sym_phys(trampoline_phys)
+trampoline_setup:
+ mov sym_phys(trampoline_phys),%ecx
+
+ /* Get bottom-most low-memory stack address. */
+ add $TRAMPOLINE_SPACE,%ecx
+
/* Save the Multiboot info struct (after relocation) for later use. */
mov $sym_phys(cpu0_stack)+1024,%esp
- push %ecx /* Boot trampoline address. */
+ push %ecx /* Bottom-most low-memory stack address. */
push %ebx /* Multiboot information address. */
push %eax /* Multiboot magic. */
call reloc
mov %eax,sym_phys(multiboot_ptr)
- /* Initialize BSS (no nasty surprises!) */
+ /*
+ * Now trampoline_phys points to the following structure (lowest address
+ * is at the bottom):
+ *
+ * +------------------------+
+ * | TRAMPOLINE_STACK_SPACE |
+ * +------------------------+
+ * | mbi data |
+ * +- - - - - - - - - - - - +
+ * | TRAMPOLINE_SPACE |
+ * +------------------------+
+ *
+ * mbi data grows downwards from the highest address of TRAMPOLINE_SPACE
+ * region to the end of the trampoline. The rest of TRAMPOLINE_SPACE is
+ * reserved for trampoline code and data.
+ */
+
+ /*
+ * Do not zero BSS on EFI platform here.
+ * It was initialized earlier.
+ */
+ cmpb $0,sym_phys(efi_platform)
+ jnz 1f
+
+ /* Initialize BSS (no nasty surprises!). */
mov $sym_phys(__bss_start),%edi
mov $sym_phys(__bss_end),%ecx
sub %edi,%ecx
@@ -231,6 +487,7 @@ trampoline_setup:
shr $2,%ecx
rep stosl
+1:
/* Interrogate CPU extended features via CPUID. */
mov $0x80000000,%eax
cpuid
@@ -282,6 +539,10 @@ trampoline_setup:
cmp $sym_phys(__trampoline_seg_stop),%edi
jb 1b
+ /* Do not parse command line on EFI platform here. */
+ cmpb $0,sym_phys(efi_platform)
+ jnz 1f
+
/* Bail if there is no command line to parse. */
mov sym_phys(multiboot_ptr),%ebx
testl $MBI_CMDLINE,MB_flags(%ebx)
@@ -292,9 +553,9 @@ trampoline_setup:
call cmdline_parse_early
1:
- /* Switch to low-memory stack. */
+ /* Switch to low-memory stack which lives at the end of trampoline region. */
mov sym_phys(trampoline_phys),%edi
- lea 0x10000(%edi),%esp
+ lea TRAMPOLINE_SPACE+TRAMPOLINE_STACK_SPACE(%edi),%esp
lea trampoline_boot_cpu_entry-trampoline_start(%edi),%eax
pushl $BOOT_CS32
push %eax
@@ -16,7 +16,7 @@
* This entry point is entered from xen/arch/x86/boot/head.S with:
* - 0x4(%esp) = MULTIBOOT_MAGIC,
* - 0x8(%esp) = MULTIBOOT_INFORMATION_ADDRESS,
- * - 0xc(%esp) = BOOT_TRAMPOLINE_ADDRESS.
+ * - 0xc(%esp) = TOPMOST_LOW_MEMORY_STACK_ADDRESS.
*/
asm (
" .text \n"
@@ -186,7 +186,7 @@ GLOBAL(idle_pg_table)
GLOBAL(__page_tables_end)
/* Init pagetables. Enough page directories to map into the bottom 1GB. */
- .section .init.data, "a", @progbits
+ .section .init.data, "aw", @progbits
.align PAGE_SIZE, 0
GLOBAL(l2_bootmap)
@@ -101,6 +101,10 @@ static void __init relocate_trampoline(unsigned long phys)
const s32 *trampoline_ptr;
trampoline_phys = phys;
+
+ if ( !efi_enabled(EFI_LOADER) )
+ return;
+
/* Apply relocations to trampoline. */
for ( trampoline_ptr = __trampoline_rel_start;
trampoline_ptr < __trampoline_rel_stop;
@@ -550,7 +554,12 @@ static void __init efi_arch_memory_setup(void)
/* Allocate space for trampoline (in first Mb). */
cfg.addr = 0x100000;
- cfg.size = trampoline_end - trampoline_start;
+
+ if ( efi_enabled(EFI_LOADER) )
+ cfg.size = trampoline_end - trampoline_start;
+ else
+ cfg.size = TRAMPOLINE_SPACE + TRAMPOLINE_STACK_SPACE;
+
status = efi_bs->AllocatePages(AllocateMaxAddress, EfiLoaderData,
PFN_UP(cfg.size), &cfg.addr);
if ( status == EFI_SUCCESS )
@@ -561,6 +570,9 @@ static void __init efi_arch_memory_setup(void)
PrintStr(L"Trampoline space cannot be allocated; will try fallback.\r\n");
}
+ if ( !efi_enabled(EFI_LOADER) )
+ return;
+
/* Initialise L2 identity-map and boot-map page table entries (16MB). */
for ( i = 0; i < 8; ++i )
{
@@ -653,6 +665,41 @@ static bool_t __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
static void efi_arch_flush_dcache_area(const void *vaddr, UINTN size) { }
+void __init efi_multiboot2(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
+{
+ EFI_GRAPHICS_OUTPUT_PROTOCOL *gop;
+ UINTN cols, gop_mode = ~0, rows;
+
+ __set_bit(EFI_BOOT, &efi_flags);
+ __set_bit(EFI_RS, &efi_flags);
+
+ efi_init(ImageHandle, SystemTable);
+
+ efi_console_set_mode();
+
+ if ( StdOut->QueryMode(StdOut, StdOut->Mode->Mode,
+ &cols, &rows) == EFI_SUCCESS )
+ efi_arch_console_init(cols, rows);
+
+ gop = efi_get_gop();
+
+ if ( gop )
+ gop_mode = efi_find_gop_mode(gop, 0, 0, 0);
+
+ efi_arch_edd();
+ efi_arch_cpu();
+
+ efi_tables();
+ setup_efi_pci();
+ efi_variables();
+ efi_arch_memory_setup();
+
+ if ( gop )
+ efi_set_gop_mode(gop, gop_mode);
+
+ efi_exit_boot(ImageHandle, SystemTable);
+}
+
/*
* Local variables:
* mode: C
@@ -3,6 +3,45 @@
#include <xen/init.h>
#include <xen/lib.h>
#include <asm/page.h>
+#include <asm/efibind.h>
+#include <efi/efidef.h>
+#include <efi/eficapsule.h>
+#include <efi/eficon.h>
+#include <efi/efidevp.h>
+#include <efi/efiapi.h>
+
+/*
+ * Here we are in EFI stub. EFI calls are not supported due to lack
+ * of relevant functionality in compiler and/or linker.
+ *
+ * efi_multiboot2() is an exception. Please look below for more details.
+ */
+
+void __init noreturn efi_multiboot2(EFI_HANDLE ImageHandle,
+ EFI_SYSTEM_TABLE *SystemTable)
+{
+ static const CHAR16 __initconst err[] =
+ L"Xen does not have EFI code build in!\r\nSystem halted!\r\n";
+ SIMPLE_TEXT_OUTPUT_INTERFACE *StdErr;
+
+ StdErr = SystemTable->StdErr ? SystemTable->StdErr : SystemTable->ConOut;
+
+ /*
+ * Print error message and halt the system.
+ *
+ * We have to open code MS x64 calling convention
+ * in assembly because here this convention may
+ * not be directly supported by C compiler.
+ */
+ asm volatile(
+ " call *%2 \n"
+ "0: hlt \n"
+ " jmp 0b \n"
+ : "+c" (StdErr) : "d" (err), "rm" (StdErr->OutputString)
+ : "rax", "r8", "r9", "r10", "r11", "memory");
+
+ unreachable();
+}
bool efi_enabled(unsigned int feature)
{
@@ -175,6 +175,8 @@ void __dummy__(void)
OFFSET(MB2_tag_type, multiboot2_tag_t, type);
OFFSET(MB2_tag_size, multiboot2_tag_t, size);
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);
BLANK();
OFFSET(DOMAIN_vm_assist, struct domain, vm_assist);
@@ -331,5 +331,8 @@ ASSERT(IS_ALIGNED(__init_end, PAGE_SIZE), "__init_end misaligned")
ASSERT(IS_ALIGNED(trampoline_start, 4), "trampoline_start misaligned")
ASSERT(IS_ALIGNED(trampoline_end, 4), "trampoline_end misaligned")
-ASSERT(IS_ALIGNED(__bss_start, 4), "__bss_start misaligned")
-ASSERT(IS_ALIGNED(__bss_end, 4), "__bss_end misaligned")
+ASSERT(IS_ALIGNED(__bss_start, 8), "__bss_start misaligned")
+ASSERT(IS_ALIGNED(__bss_end, 8), "__bss_end misaligned")
+
+ASSERT((trampoline_end - trampoline_start) < TRAMPOLINE_SPACE - MBI_SPACE_MIN,
+ "not enough room for trampoline and mbi data")
@@ -79,6 +79,17 @@ static size_t wstrlen(const CHAR16 * s);
static int set_color(u32 mask, int bpp, u8 *pos, u8 *sz);
static bool_t match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2);
+static void efi_init(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable);
+static void efi_console_set_mode(void);
+static EFI_GRAPHICS_OUTPUT_PROTOCOL *efi_get_gop(void);
+static UINTN efi_find_gop_mode(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop,
+ UINTN cols, UINTN rows, UINTN depth);
+static void efi_tables(void);
+static void setup_efi_pci(void);
+static void efi_variables(void);
+static void efi_set_gop_mode(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop, UINTN gop_mode);
+static void efi_exit_boot(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable);
+
static const EFI_BOOT_SERVICES *__initdata efi_bs;
static UINT32 __initdata efi_bs_revision;
static EFI_HANDLE __initdata efi_ih;
@@ -73,6 +73,11 @@
#define STACK_ORDER 3
#define STACK_SIZE (PAGE_SIZE << STACK_ORDER)
+#define TRAMPOLINE_STACK_SPACE PAGE_SIZE
+#define TRAMPOLINE_SPACE (KB(64) - TRAMPOLINE_STACK_SPACE)
+
+#define MBI_SPACE_MIN (2 * PAGE_SIZE)
+
/* Primary stack is restricted to 8kB by guard pages. */
#define PRIMARY_STACK_SIZE 8192
@@ -70,6 +70,7 @@
#define __force
#define __bitwise
+#define KB(_kb) (_AC(_kb, ULL) << 10)
#define MB(_mb) (_AC(_mb, ULL) << 20)
#define GB(_gb) (_AC(_gb, ULL) << 30)
This way Xen can be loaded on EFI platforms using GRUB2 and other boot loaders which support multiboot2 protocol. Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> --- v14 - suggestions/fixes: - mark .init.data section as writable; by the way we must change similar definition in xen/arch/x86/boot/x86_64.S because otherwise compiler complains about section types conflicts (suggested by Jan Beulich), - use %r15 instead of %r15d (suggested by Jan Beulich), - remove redundant add from UEFI stack alignment (suggested by Jan Beulich), - use "mov (%rsp),%rdi" instead of "pop %rdi/push %rdi" (suggested by Jan Beulich), - return void instead of paddr_t from efi_multiboot2() and then simplify a bit trampoline setup assembly (suggested by Jan Beulich), - remove "(XEN)" from efi_multiboot2() stub error messages (suggested by Jan Beulich), - move err from inline assembly OutputOperands to InputOperands in stub.c:efi_multiboot2(); this way we avoid following compile time error: stub.c: In function ‘efi_multiboot2’: stub.c:36:5: error: read-only variable ‘err’ used as ‘asm’ output asm volatile( ^~~ issue was introduced by changing err type to "static const CHAR16 __initconst"; potentially we can revert this change but move to InputOperands looks better IMO; even if we are not able to specify %rdx in Clobbers; simply we do not care because next instruction after call is hlt (discovered by Konrad Rzeszutek Wilk and Marcos Matsunaga), - take into account MBI_SPACE_MIN in ASSERT((trampoline_end - trampoline_start) < ...) (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich). v13 - suggestions/fixes: - move vga_text_buffer and efi_platform to .init.data section (suggested by Jan Beulich), - reduce number of error branches in EFI code in xen/arch/x86/boot/head.S (suggested by Jan Beulich), - rename run_bs label to .Lrun_bs (suggested by Jan Beulich), - align the stack as UEFI spec requires (suggested by Jan Beulich), - change trampoline region memory layout (suggested by Jan Beulich), - revert changes in efi_arch_pre_exit_boot() (suggested by Jan Beulich), - relocate_trampoline() must set trampoline_phys for all bootloaders; otherwise fallback allocator is always used if Xen was loaded with Multiboot2 protocol, - change err type in efi_multiboot2() to "static const CHAR16 __initconst" (suggested by Jan Beulich), - change asm "g" constraint to "rm" in efi_multiboot2() (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich and Doug Goldstein). v12 - suggestions/fixes: - rename __efi64_start to __efi64_mb2_start (suggested by Andrew Cooper), - use efi_arch_memory_setup() machinery as trampoline et consortes main memory allocator (suggested by Doug Goldstein), - allocate space for mbi struct in efi_arch_memory_setup() too; this thing was not taken into account in earlier releases, - revert trampoline et consortes fallback memory allocator code in efi_arch_process_memory_map() to current upstream state (suggested by Doug Goldstein), - further simplify efi_arch_pre_exit_boot() code, - call efi_arch_memory_setup() from efi_multiboot2() (suggested by Doug Goldstein), - fix asembly call argument in xen/arch/x86/efi/stub.c (suggested by Andrew Cooper), - add ASSERT() for trampoline size (suggested by Doug Goldstein), - add KB() macro (suggested by Doug Goldstein), - improve comments (suggested by Andrew Cooper and Doug Goldstein). v10 - suggestions/fixes: - replace ljmpl with lretq (suggested by Andrew Cooper), - introduce efi_platform to increase code readability (suggested by Andrew Cooper). v9 - suggestions/fixes: - use .L labels instead of numeric ones in multiboot2 data scanning loops (suggested by Jan Beulich). v8 - suggestions/fixes: - use __bss_start(%rip)/__bss_end(%rip) instead of of .startof.(.bss)(%rip)/$.sizeof.(.bss) because latter is not tested extensively in different built environments yet (suggested by Andrew Cooper), - fix multiboot2 data scanning loop in x86_32 code (suggested by Jan Beulich), - add check for extra mem for mbi data if Xen is loaded via multiboot2 protocol on EFI platform (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich). v7 - suggestions/fixes: - do not allocate twice memory for trampoline if we were loaded via multiboot2 protocol on EFI platform, - wrap long line (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich). v6 - suggestions/fixes: - improve label names in assembly error printing code (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - various minor cleanups and fixes (suggested by Jan Beulich). v4 - suggestions/fixes: - remove redundant BSS alignment, - update BSS alignment check, - use __set_bit() instead of set_bit() if possible (suggested by Jan Beulich), - call efi_arch_cpu() from efi_multiboot2() even if the same work is done later in other place right now (suggested by Jan Beulich), - xen/arch/x86/efi/stub.c:efi_multiboot2() fail properly on EFI platforms, - do not read data beyond the end of multiboot2 information in xen/arch/x86/boot/head.S (suggested by Jan Beulich), - use 32-bit registers in x86_64 code if possible (suggested by Jan Beulich), - multiboot2 information address is 64-bit in x86_64 code, so, treat it is as is (suggested by Jan Beulich), - use cmovcc if possible, - leave only one space between rep and stosq (suggested by Jan Beulich), - improve error handling, - improve early error messages, (suggested by Jan Beulich), - improve early error messages printing code, - improve label names (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - various minor cleanups. v3 - suggestions/fixes: - take into account alignment when skipping multiboot2 fixed part (suggested by Konrad Rzeszutek Wilk), - improve segment registers initialization (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich and Konrad Rzeszutek Wilk), - improve commit message (suggested by Jan Beulich). v2 - suggestions/fixes: - generate multiboot2 header using macros (suggested by Jan Beulich), - switch CPU to x86_32 mode before jumping to 32-bit code (suggested by Andrew Cooper), - reduce code changes to increase patch readability (suggested by Jan Beulich), - improve comments (suggested by Jan Beulich), - ignore MULTIBOOT2_TAG_TYPE_BASIC_MEMINFO tag on EFI platform and find on my own multiboot2.mem_lower value, - stop execution if EFI platform is detected in legacy BIOS path. --- xen/arch/x86/boot/head.S | 297 ++++++++++++++++++++++++++++++++++--- xen/arch/x86/boot/reloc.c | 2 +- xen/arch/x86/boot/x86_64.S | 2 +- xen/arch/x86/efi/efi-boot.h | 49 +++++- xen/arch/x86/efi/stub.c | 39 +++++ xen/arch/x86/x86_64/asm-offsets.c | 2 + xen/arch/x86/xen.lds.S | 7 +- xen/common/efi/boot.c | 11 ++ xen/include/asm-x86/config.h | 5 + xen/include/xen/config.h | 1 + 10 files changed, 392 insertions(+), 23 deletions(-)