2 * Copyright C 2016, Oracle and/or its affiliates. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program. If not, see <http://www.gnu.org/licenses/>.
20 #define _pa(x) ((x) - __START_KERNEL_map)
22 #include <linux/elfnote.h>
23 #include <linux/init.h>
24 #include <linux/linkage.h>
25 #include <asm/segment.h>
28 #include <asm/processor-flags.h>
30 #include <xen/interface/elfnote.h>
35 * Entry point for PVH guests.
37 * Xen ABI specifies the following register state when we come here:
39 * - `ebx`: contains the physical memory address where the loader has placed
40 * the boot start info structure.
41 * - `cr0`: bit 0 (PE) must be set. All the other writeable bits are cleared.
42 * - `cr4`: all bits are cleared.
43 * - `cs `: must be a 32-bit read/execute code segment with a base of ‘0’
44 * and a limit of ‘0xFFFFFFFF’. The selector value is unspecified.
45 * - `ds`, `es`: must be a 32-bit read/write data segment with a base of
46 * ‘0’ and a limit of ‘0xFFFFFFFF’. The selector values are all
48 * - `tr`: must be a 32-bit TSS (active) with a base of '0' and a limit
50 * - `eflags`: bit 17 (VM) must be cleared. Bit 9 (IF) must be cleared.
51 * Bit 8 (TF) must be cleared. Other bits are all unspecified.
53 * All other processor registers and flag bits are unspecified. The OS is in
54 * charge of setting up it's own stack, GDT and IDT.
67 /* Stash hvm_start_info. */
68 mov $_pa(pvh_start_info), %edi
70 mov _pa(pvh_start_info_sz), %ecx
75 mov $_pa(early_stack_end), %esp
77 /* Enable PAE mode. */
79 orl $X86_CR4_PAE, %eax
83 /* Enable Long mode. */
89 /* Enable pre-constructed page tables. */
90 mov $_pa(init_level4_pgt), %eax
92 mov $(X86_CR0_PG | X86_CR0_PE), %eax
95 /* Jump to 64-bit mode. */
96 ljmp $__KERNEL_CS, $_pa(1f)
98 /* 64-bit entry point. */
103 /* startup_64 expects boot_params in %rsi. */
104 mov $_pa(pvh_bootparams), %rsi
105 mov $_pa(startup_64), %rax
108 #else /* CONFIG_X86_64 */
110 call mk_early_pgtbl_32
112 mov $_pa(initial_page_table), %eax
116 or $(X86_CR0_PG | X86_CR0_PE), %eax
122 mov $_pa(pvh_bootparams), %esi
124 /* startup_32 doesn't expect paging and PAE to be on. */
125 ljmp $__BOOT_CS, $_pa(2f)
128 and $~X86_CR0_PG, %eax
131 and $~X86_CR4_PAE, %eax
134 ljmp $__BOOT_CS, $_pa(startup_32)
138 .section ".init.data","aw"
141 .word gdt_end - gdt_start
145 .quad 0x0000000000000000 /* NULL descriptor */
146 .quad 0x0000000000000000 /* reserved */
148 .quad GDT_ENTRY(0xa09a, 0, 0xfffff) /* __KERNEL_CS */
150 .quad GDT_ENTRY(0xc09a, 0, 0xfffff) /* __KERNEL_CS */
152 .quad GDT_ENTRY(0xc092, 0, 0xfffff) /* __KERNEL_DS */
160 ELFNOTE(Xen, XEN_ELFNOTE_PHYS32_ENTRY,
161 _ASM_PTR (pvh_start_xen - __START_KERNEL_map))