1 ;;;; This file contains some parameterizations of various VM
2 ;;;; attributes for the x86. This file is separate from other stuff so
3 ;;;; that it can be compiled and loaded earlier.
5 ;;;; This software is part of the SBCL system. See the README file for
8 ;;;; This software is derived from the CMU CL system, which was
9 ;;;; written at Carnegie Mellon University and released into the
10 ;;;; public domain. The software is in the public domain and is
11 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
12 ;;;; files for more information.
16 ;;; ### Note: we simultaneously use ``word'' to mean a 32 bit quantity
17 ;;; and a 16 bit quantity depending on context. This is because Intel
18 ;;; insists on calling 16 bit things words and 32 bit things
19 ;;; double-words (or dwords). Therefore, in the instruction definition
20 ;;; and register specs, we use the Intel convention. But whenever we
21 ;;; are talking about stuff the rest of the lisp system might be
22 ;;; interested in, we use ``word'' to mean the size of a descriptor
23 ;;; object, which is 32 bits.
25 ;;;; machine architecture parameters
27 ;;; the number of bits per word, where a word holds one lisp descriptor
28 (def!constant n-word-bits 32)
30 ;;; the natural width of a machine word (as seen in e.g. register width,
32 (def!constant n-machine-word-bits 32)
34 ;;; the number of bits per byte, where a byte is the smallest
35 ;;; addressable object
36 (def!constant n-byte-bits 8)
38 ;;; The size in bytes of the GENCGC pages. Should be a multiple of the
39 ;;; architecture code size.
40 (def!constant gencgc-page-size 4096)
42 (def!constant float-sign-shift 31)
44 ;;; comment from CMU CL:
45 ;;; These values were taken from the alpha code. The values for
46 ;;; bias and exponent min/max are not the same as shown in the 486 book.
47 ;;; They may be correct for how Python uses them.
48 (def!constant single-float-bias 126) ; Intel says 127.
49 (defconstant-eqx single-float-exponent-byte (byte 8 23) #'equalp)
50 (defconstant-eqx single-float-significand-byte (byte 23 0) #'equalp)
51 ;;; comment from CMU CL:
52 ;;; The 486 book shows the exponent range -126 to +127. The Lisp
53 ;;; code that uses these values seems to want already biased numbers.
54 (def!constant single-float-normal-exponent-min 1)
55 (def!constant single-float-normal-exponent-max 254)
56 (def!constant single-float-hidden-bit (ash 1 23))
57 (def!constant single-float-trapping-nan-bit (ash 1 22))
59 (def!constant double-float-bias 1022)
60 (defconstant-eqx double-float-exponent-byte (byte 11 20) #'equalp)
61 (defconstant-eqx double-float-significand-byte (byte 20 0) #'equalp)
62 (def!constant double-float-normal-exponent-min 1)
63 (def!constant double-float-normal-exponent-max #x7FE)
64 (def!constant double-float-hidden-bit (ash 1 20))
65 (def!constant double-float-trapping-nan-bit (ash 1 19))
67 (def!constant long-float-bias 16382)
68 (defconstant-eqx long-float-exponent-byte (byte 15 0) #'equalp)
69 (defconstant-eqx long-float-significand-byte (byte 31 0) #'equalp)
70 (def!constant long-float-normal-exponent-min 1)
71 (def!constant long-float-normal-exponent-max #x7FFE)
72 (def!constant long-float-hidden-bit (ash 1 31)) ; actually not hidden
73 (def!constant long-float-trapping-nan-bit (ash 1 30))
75 (def!constant single-float-digits
76 (+ (byte-size single-float-significand-byte) 1))
78 (def!constant double-float-digits
79 (+ (byte-size double-float-significand-byte) n-word-bits 1))
81 (def!constant long-float-digits
82 (+ (byte-size long-float-significand-byte) n-word-bits 1))
84 ;;; pfw -- from i486 microprocessor programmer's reference manual
85 (def!constant float-invalid-trap-bit (ash 1 0))
86 (def!constant float-denormal-trap-bit (ash 1 1))
87 (def!constant float-divide-by-zero-trap-bit (ash 1 2))
88 (def!constant float-overflow-trap-bit (ash 1 3))
89 (def!constant float-underflow-trap-bit (ash 1 4))
90 (def!constant float-inexact-trap-bit (ash 1 5))
92 (def!constant float-round-to-nearest 0)
93 (def!constant float-round-to-negative 1)
94 (def!constant float-round-to-positive 2)
95 (def!constant float-round-to-zero 3)
97 (def!constant float-precision-24-bit 0)
98 (def!constant float-precision-53-bit 2)
99 (def!constant float-precision-64-bit 3)
101 (defconstant-eqx float-rounding-mode (byte 2 10) #'equalp)
102 (defconstant-eqx float-sticky-bits (byte 6 16) #'equalp)
103 (defconstant-eqx float-traps-byte (byte 6 0) #'equalp)
104 (defconstant-eqx float-exceptions-byte (byte 6 16) #'equalp)
105 (defconstant-eqx float-precision-control (byte 2 8) #'equalp)
106 (def!constant float-fast-bit 0) ; no fast mode on x86
108 ;;;; description of the target address space
110 ;;; where to put the different spaces
112 ;;; Note: Mostly these values are black magic, inherited from CMU CL
113 ;;; without any documentation. However, there were a few explanatory
114 ;;; comments in the CMU CL sources:
116 ;;; ** The space 0x08000000-0x10000000 is "C program and memory allocation".
117 ;;; ** The space 0x40000000-0x48000000 is reserved for shared libs.
118 ;;; ** The space >0xE0000000 is "C stack - Alien stack".
120 ;;; ** The space 0x0E000000-0x10000000 is "Foreign segment".
121 ;;; ** The space 0x20000000-0x30000000 is reserved for shared libs.
122 ;;; And there have been some changes since the fork from CMU CL:
123 ;;; * The OpenBSD port is new since the fork. We started with
124 ;;; the FreeBSD address map, which actually worked until the
125 ;;; Alpha port patches, for reasons which in retrospect are rather
126 ;;; mysterious. After the Alpha port patches were added, the
127 ;;; OpenBSD port suffered memory corruption problems. While
128 ;;; debugging those, it was discovered that src/runtime/trymap
129 ;;; failed for the control stack region #x40000000-#x47fff000.
130 ;;; After the control stack was moved upward out of this region
131 ;;; (stealing some bytes from dynamic space) the problems went
133 ;;; * The FreeBSD STATIC-SPACE-START value was bumped up from
134 ;;; #x28000000 to #x30000000 when FreeBSD ld.so dynamic linking
135 ;;; support was added for FreeBSD ca. 20000910. This was to keep from
136 ;;; stomping on an address range that the dynamic libraries want to
137 ;;; use. (They want to use this address range even if we try to
138 ;;; reserve it with a call to validate() as the first operation in
140 ;;; * For NetBSD 2.0, the following ranges are used by normal
141 ;;; executables and mmap:
142 ;;; ** Executables are (by default) loaded at 0x08048000.
143 ;;; ** The break for the sbcl runtime seems to end around 0x08400000
144 ;;; We set read only space around 0x20000000, static
145 ;;; space around 0x30000000, all ending below 0x37fff000
146 ;;; ** ld.so and other mmap'ed stuff like shared libs start around
148 ;;; We set dynamic space between 0x60000000 and 0x98000000
149 ;;; ** Bottom of the stack is typically not below 0xb0000000
150 ;;; FYI, this can be looked at with the "pmap" program, and if you
151 ;;; set the top-down mmap allocation option in the kernel (not yet
152 ;;; the default), all bets are totally off!
156 (def!constant read-only-space-start #x01000000)
157 (def!constant read-only-space-end #x037ff000)
159 (def!constant static-space-start #x05000000)
160 (def!constant static-space-end #x07fff000)
162 (def!constant dynamic-space-start #x09000000)
163 (def!constant dynamic-space-end #x29000000)
165 (def!constant linkage-table-space-start #x70000000)
166 (def!constant linkage-table-space-end #x7ffff000))
170 (def!constant read-only-space-start #x20000000)
171 (def!constant read-only-space-end #x2ffff000)
173 (def!constant static-space-start #x40000000)
174 (def!constant static-space-end #x42fff000)
176 (def!constant dynamic-space-start #x48000000)
177 (def!constant dynamic-space-end #xA0000000)
179 (def!constant linkage-table-space-start #xA2000000)
180 (def!constant linkage-table-space-end #xA3000000))
184 (def!constant read-only-space-start #x10000000)
185 (def!constant read-only-space-end #x1ffff000)
187 (def!constant static-space-start #x30000000)
188 (def!constant static-space-end #x37fff000)
190 (def!constant dynamic-space-start #x48000000)
191 (def!constant dynamic-space-end #x88000000)
193 ;; In CMUCL: 0xB0000000->0xB1000000
194 (def!constant linkage-table-space-start #x90000000)
195 (def!constant linkage-table-space-end #x91000000))
199 (def!constant read-only-space-start #x40000000)
200 (def!constant read-only-space-end #x47fff000)
202 (def!constant static-space-start #x50000000)
203 (def!constant static-space-end #x5ffff000)
205 (def!constant dynamic-space-start #x80000000)
206 (def!constant dynamic-space-end #xA0000000)
208 ;; In CMUCL: 0xB0000000->0xB1000000
209 (def!constant linkage-table-space-start #xA0000000)
210 (def!constant linkage-table-space-end #xA1000000))
214 (def!constant read-only-space-start #x20000000)
215 (def!constant read-only-space-end #x2ffff000)
217 (def!constant static-space-start #x30000000)
218 (def!constant static-space-end #x37fff000)
220 (def!constant dynamic-space-start #x60000000)
221 (def!constant dynamic-space-end #x98000000)
223 ;; In CMUCL: 0xB0000000->0xB1000000
224 (def!constant linkage-table-space-start #xA0000000)
225 (def!constant linkage-table-space-end #xA1000000))
227 ;;; Size of one linkage-table entry in bytes.
228 (def!constant linkage-table-entry-size 8)
230 ;;; Given that NIL is the first thing allocated in static space, we
231 ;;; know its value at compile time:
232 (def!constant nil-value (+ static-space-start #xb))
234 ;;;; other miscellaneous constants
236 (defenum (:suffix -trap :start 8)
243 single-step-breakpoint)
244 ;;; FIXME: It'd be nice to replace all the DEFENUMs with something like
245 ;;; (WITH-DEF-ENUM (:START 8)
246 ;;; (DEF-ENUM HALT-TRAP)
247 ;;; (DEF-ENUM PENDING-INTERRUPT-TRAP)
249 ;;; for the benefit of anyone doing a lexical search for definitions
250 ;;; of these symbols.
252 (defenum (:prefix object-not- :suffix -trap :start 16)
256 (defenum (:prefix trace-table-)
264 ;;; These symbols are loaded into static space directly after NIL so
265 ;;; that the system can compute their address by adding a constant
268 ;;; The fdefn objects for the static functions are loaded into static
269 ;;; space directly after the static symbols. That way, the raw-addr
270 ;;; can be loaded directly out of them by indirecting relative to NIL.
272 ;;; pfw X86 doesn't have enough registers to keep these things there.
273 ;;; Note these spaces grow from low to high addresses.
274 (defvar *allocation-pointer*)
275 (defvar *binding-stack-pointer*)
277 ;;; FIXME: !COLD-INIT probably doesn't need
278 ;;; to be in the static symbols table any more.
279 (defparameter *static-symbols*
282 ;; The C startup code must fill these in.
285 ;; functions that the C code needs to call. When adding to this list,
286 ;; also add a `frob' form in genesis.lisp finish-symbols.
288 sb!kernel::internal-error
289 sb!kernel::control-stack-exhausted-error
290 sb!kernel::undefined-alien-variable-error
291 sb!kernel::undefined-alien-function-error
292 sb!kernel::memory-fault-error
293 sb!di::handle-breakpoint
298 ;; Note that these are FIXNUM word counts, not (as one might
299 ;; expect) byte counts or SAPs. The reason seems to be that by
300 ;; representing them this way, we can avoid consing bignums.
302 *read-only-space-free-pointer*
303 *static-space-free-pointer*
304 *initial-dynamic-space-free-pointer*
306 ;; things needed for non-local exit
307 *current-catch-block*
308 *current-unwind-protect-block*
311 ;; interrupt handling
312 *pseudo-atomic-atomic*
313 *pseudo-atomic-interrupted*
314 sb!unix::*interrupts-enabled*
315 sb!unix::*interrupt-pending*
316 *free-interrupt-context-index*
318 #!+sb-thread *stop-for-gc-pending*
320 #!+sb-thread sb!thread::run-interruption
326 *binding-stack-pointer*
327 *binding-stack-start*
328 *control-stack-start*
331 ;; the floating point constants
336 ;; The following are all long-floats.
346 *restart-lisp-function*
348 ;; The ..SLOT-UNBOUND.. symbol is static in order to optimise the
349 ;; common slot unbound check.
351 ;; FIXME: In SBCL, the CLOS code has become sufficiently tightly
352 ;; integrated into the system that it'd probably make sense to use
353 ;; the ordinary unbound marker for this.
354 sb!pcl::..slot-unbound..
357 (defparameter *static-funs*
368 sb!kernel:two-arg-and
369 sb!kernel:two-arg-ior
370 sb!kernel:two-arg-xor
371 sb!kernel:two-arg-gcd
372 sb!kernel:two-arg-lcm))
374 ;;;; stuff added by jrd
376 ;;; FIXME: Is this used? Delete it or document it.
377 ;;; cf the sparc PARMS.LISP
378 (defparameter *assembly-unit-length* 8)