xref: /openbmc/linux/include/xen/interface/elfnote.h (revision 799a545b)
1 /******************************************************************************
2  * elfnote.h
3  *
4  * Definitions used for the Xen ELF notes.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  *
24  * Copyright (c) 2006, Ian Campbell, XenSource Ltd.
25  */
26 
27 #ifndef __XEN_PUBLIC_ELFNOTE_H__
28 #define __XEN_PUBLIC_ELFNOTE_H__
29 
30 /*
31  * The notes should live in a SHT_NOTE segment and have "Xen" in the
32  * name field.
33  *
34  * Numeric types are either 4 or 8 bytes depending on the content of
35  * the desc field.
36  *
37  * LEGACY indicated the fields in the legacy __xen_guest string which
38  * this a note type replaces.
39  *
40  * String values (for non-legacy) are NULL terminated ASCII, also known
41  * as ASCIZ type.
42  */
43 
44 /*
45  * NAME=VALUE pair (string).
46  */
47 #define XEN_ELFNOTE_INFO           0
48 
49 /*
50  * The virtual address of the entry point (numeric).
51  *
52  * LEGACY: VIRT_ENTRY
53  */
54 #define XEN_ELFNOTE_ENTRY          1
55 
56 /* The virtual address of the hypercall transfer page (numeric).
57  *
58  * LEGACY: HYPERCALL_PAGE. (n.b. legacy value is a physical page
59  * number not a virtual address)
60  */
61 #define XEN_ELFNOTE_HYPERCALL_PAGE 2
62 
63 /* The virtual address where the kernel image should be mapped (numeric).
64  *
65  * Defaults to 0.
66  *
67  * LEGACY: VIRT_BASE
68  */
69 #define XEN_ELFNOTE_VIRT_BASE      3
70 
71 /*
72  * The offset of the ELF paddr field from the acutal required
73  * pseudo-physical address (numeric).
74  *
75  * This is used to maintain backwards compatibility with older kernels
76  * which wrote __PAGE_OFFSET into that field. This field defaults to 0
77  * if not present.
78  *
79  * LEGACY: ELF_PADDR_OFFSET. (n.b. legacy default is VIRT_BASE)
80  */
81 #define XEN_ELFNOTE_PADDR_OFFSET   4
82 
83 /*
84  * The version of Xen that we work with (string).
85  *
86  * LEGACY: XEN_VER
87  */
88 #define XEN_ELFNOTE_XEN_VERSION    5
89 
90 /*
91  * The name of the guest operating system (string).
92  *
93  * LEGACY: GUEST_OS
94  */
95 #define XEN_ELFNOTE_GUEST_OS       6
96 
97 /*
98  * The version of the guest operating system (string).
99  *
100  * LEGACY: GUEST_VER
101  */
102 #define XEN_ELFNOTE_GUEST_VERSION  7
103 
104 /*
105  * The loader type (string).
106  *
107  * LEGACY: LOADER
108  */
109 #define XEN_ELFNOTE_LOADER         8
110 
111 /*
112  * The kernel supports PAE (x86/32 only, string = "yes" or "no").
113  *
114  * LEGACY: PAE (n.b. The legacy interface included a provision to
115  * indicate 'extended-cr3' support allowing L3 page tables to be
116  * placed above 4G. It is assumed that any kernel new enough to use
117  * these ELF notes will include this and therefore "yes" here is
118  * equivalent to "yes[entended-cr3]" in the __xen_guest interface.
119  */
120 #define XEN_ELFNOTE_PAE_MODE       9
121 
122 /*
123  * The features supported/required by this kernel (string).
124  *
125  * The string must consist of a list of feature names (as given in
126  * features.h, without the "XENFEAT_" prefix) separated by '|'
127  * characters. If a feature is required for the kernel to function
128  * then the feature name must be preceded by a '!' character.
129  *
130  * LEGACY: FEATURES
131  */
132 #define XEN_ELFNOTE_FEATURES      10
133 
134 /*
135  * The kernel requires the symbol table to be loaded (string = "yes" or "no")
136  * LEGACY: BSD_SYMTAB (n.b. The legacy treated the presence or absence
137  * of this string as a boolean flag rather than requiring "yes" or
138  * "no".
139  */
140 #define XEN_ELFNOTE_BSD_SYMTAB    11
141 
142 /*
143  * The lowest address the hypervisor hole can begin at (numeric).
144  *
145  * This must not be set higher than HYPERVISOR_VIRT_START. Its presence
146  * also indicates to the hypervisor that the kernel can deal with the
147  * hole starting at a higher address.
148  */
149 #define XEN_ELFNOTE_HV_START_LOW  12
150 
151 /*
152  * List of maddr_t-sized mask/value pairs describing how to recognize
153  * (non-present) L1 page table entries carrying valid MFNs (numeric).
154  */
155 #define XEN_ELFNOTE_L1_MFN_VALID  13
156 
157 /*
158  * Whether or not the guest supports cooperative suspend cancellation.
159  * This is a numeric value.
160  *
161  * Default is 0
162  */
163 #define XEN_ELFNOTE_SUSPEND_CANCEL 14
164 
165 /*
166  * The (non-default) location the initial phys-to-machine map should be
167  * placed at by the hypervisor (Dom0) or the tools (DomU).
168  * The kernel must be prepared for this mapping to be established using
169  * large pages, despite such otherwise not being available to guests.
170  * The kernel must also be able to handle the page table pages used for
171  * this mapping not being accessible through the initial mapping.
172  * (Only x86-64 supports this at present.)
173  */
174 #define XEN_ELFNOTE_INIT_P2M      15
175 
176 /*
177  * Whether or not the guest can deal with being passed an initrd not
178  * mapped through its initial page tables.
179  */
180 #define XEN_ELFNOTE_MOD_START_PFN 16
181 
182 /*
183  * The features supported by this kernel (numeric).
184  *
185  * Other than XEN_ELFNOTE_FEATURES on pre-4.2 Xen, this note allows a
186  * kernel to specify support for features that older hypervisors don't
187  * know about. The set of features 4.2 and newer hypervisors will
188  * consider supported by the kernel is the combination of the sets
189  * specified through this and the string note.
190  *
191  * LEGACY: FEATURES
192  */
193 #define XEN_ELFNOTE_SUPPORTED_FEATURES 17
194 
195 /*
196  * The number of the highest elfnote defined.
197  */
198 #define XEN_ELFNOTE_MAX XEN_ELFNOTE_SUPPORTED_FEATURES
199 
200 #endif /* __XEN_PUBLIC_ELFNOTE_H__ */
201 
202 /*
203  * Local variables:
204  * mode: C
205  * c-set-style: "BSD"
206  * c-basic-offset: 4
207  * tab-width: 4
208  * indent-tabs-mode: nil
209  * End:
210  */
211