.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!"
.Lbag_alg_msg: .asciz "ERR: Xen must be loaded at a 2Mb boundary!"
.Lno_nx_msg: .asciz "ERR: Not an NX-capable CPU!"
mov $sym_offs(.Lno_nx_msg), %ecx
jmp .Lget_vtb
#endif
-.Lmb2_no_st:
- /*
- * Here we are on EFI platform. vga_text_buffer was zapped earlier
- * because there is pretty good chance that VGA is unavailable.
- */
- mov $sym_offs(.Lbad_ldr_nst), %ecx
- jmp .Lget_vtb
-.Lmb2_no_ih:
- /* Ditto. */
- mov $sym_offs(.Lbad_ldr_nih), %ecx
- jmp .Lget_vtb
.Lmb2_no_bs:
/*
* Ditto. Additionally, here there is a chance that Xen was started
mov $sym_offs(.Lbad_efi_msg), %ecx
xor %edi,%edi # No VGA text buffer
jmp .Lprint_err
+.Ldirect_error:
+ mov sym_esi(vga_text_buffer), %edi
+ mov %eax, %esi
+ jmp 1f
.Lget_vtb:
mov sym_esi(vga_text_buffer), %edi
.Lprint_err:
/*
* Align the stack as UEFI spec requires. Keep it aligned
- * before efi_multiboot2() call by pushing/popping even
+ * before efi_multiboot2_prelude() call by pushing/popping even
* numbers of items on it.
*/
and $~15, %rsp
+ /* Save magic number, we need it later but we need to use %eax. */
+ mov %eax, %edx
+
/*
* Initialize BSS (no nasty surprises!).
* It must be done earlier than in BIOS case
- * because efi_multiboot2() touches it.
+ * because efi_multiboot2_prelude() touches it.
*/
- mov %eax, %edx
lea __bss_start(%rip), %edi
lea __bss_end(%rip), %ecx
sub %edi, %ecx
shr $3, %ecx
xor %eax, %eax
rep stosq
- mov %edx, %eax
-
- /* Check for Multiboot2 bootloader. */
- cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax
- je .Lefi_multiboot2_proto
-
- /* Jump to .Lnot_multiboot after switching CPU to x86_32 mode. */
- lea .Lnot_multiboot(%rip), %r15
- jmp x86_32_switch
-.Lefi_multiboot2_proto:
- /* Zero EFI SystemTable, EFI ImageHandle addresses and cmdline. */
- xor %esi,%esi
- xor %edi,%edi
- xor %edx,%edx
-
- /* 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
+ /*
+ * Spill MB2 magic.
+ * Spill the pointer too, to keep the stack aligned.
+ */
+ push %rdx
+ push %rbx
- /* Are EFI boot services available? */
- cmpl $MULTIBOOT2_TAG_TYPE_EFI_BS,MB2_tag_type(%rcx)
- jne .Lefi_mb2_st
+ /*
+ * efi_multiboot2_prelude() is called according to System V AMD64 ABI:
+ * - IN: %edi - Multiboot2 magic,
+ * %rsi - Multiboot2 pointer.
+ * - OUT: %rax - error string.
+ */
+ mov %edx, %edi
+ mov %rbx, %rsi
+ call efi_multiboot2_prelude
+ lea .Ldirect_error(%rip), %r15
+ test %rax, %rax
+ jnz x86_32_switch
+
+ /* Restore Multiboot2 pointer and magic. */
+ pop %rbx
+ pop %rax
/* We are on EFI platform and EFI boot services are available. */
incb efi_platform(%rip)
* 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
-
- /* Get command line from Multiboot2 information. */
- cmpl $MULTIBOOT2_TAG_TYPE_CMDLINE, MB2_tag_type(%rcx)
- jne .Lno_cmdline
- lea MB2_tag_string(%rcx), %rdx
- jmp .Lefi_mb2_next_tag
-.Lno_cmdline:
-
- /* 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
-
- /* Save Multiboot2 magic on the stack. */
- push %rax
-
- /* Save EFI ImageHandle on the stack. */
- push %rdi
-
- /*
- * efi_multiboot2() is called according to System V AMD64 ABI:
- * - IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable,
- * %rdx - MB2 cmdline
- */
- 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
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <xen/efi.h>
+#include <xen/init.h>
+#include <xen/multiboot2.h>
+#include <asm/asm_defns.h>
+#include <asm/efi.h>
+
+const char * asmlinkage __init
+efi_multiboot2_prelude(uint32_t magic, const multiboot2_fixed_t *mbi)
+{
+ const multiboot2_tag_t *tag;
+ EFI_HANDLE ImageHandle = NULL;
+ EFI_SYSTEM_TABLE *SystemTable = NULL;
+ const char *cmdline = NULL;
+ bool have_bs = false;
+
+ if ( magic != MULTIBOOT2_BOOTLOADER_MAGIC )
+ return "ERR: Not a Multiboot2 bootloader!";
+
+ /* Skip Multiboot2 information fixed part. */
+ tag = _p(ROUNDUP((unsigned long)(mbi + 1), MULTIBOOT2_TAG_ALIGN));
+
+ for ( ; (const void *)tag - (const void *)mbi < mbi->total_size &&
+ tag->type != MULTIBOOT2_TAG_TYPE_END;
+ tag = _p(ROUNDUP((unsigned long)tag + tag->size,
+ MULTIBOOT2_TAG_ALIGN)) )
+ {
+ switch ( tag->type )
+ {
+ case MULTIBOOT2_TAG_TYPE_EFI_BS:
+ have_bs = true;
+ break;
+
+ case MULTIBOOT2_TAG_TYPE_EFI64:
+ SystemTable = _p(((const multiboot2_tag_efi64_t *)tag)->pointer);
+ break;
+
+ case MULTIBOOT2_TAG_TYPE_EFI64_IH:
+ ImageHandle = _p(((const multiboot2_tag_efi64_ih_t *)tag)->pointer);
+ break;
+
+ case MULTIBOOT2_TAG_TYPE_CMDLINE:
+ cmdline = ((const multiboot2_tag_string_t *)tag)->string;
+ break;
+
+ default:
+ /* Satisfy MISRA requirement. */
+ break;
+ }
+ }
+
+ if ( !have_bs )
+ return "ERR: Bootloader shutdown EFI x64 boot services!";
+ if ( !SystemTable )
+ return "ERR: EFI SystemTable is not provided by bootloader!";
+ if ( !ImageHandle )
+ return "ERR: EFI ImageHandle is not provided by bootloader!";
+
+ efi_multiboot2(ImageHandle, SystemTable, cmdline);
+
+ return NULL;
+}
projects / xen.git / commitdiff