File : s-bbpara-xtratum-sparc.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- S Y S T E M . B B . P A R A M E T E R S --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1999-2002 Universidad Politecnica de Madrid --
10 -- Copyright (C) 2003-2005 The European Space Agency --
11 -- Copyright (C) 2003-2012, AdaCore --
12 -- --
13 -- GNARL is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 3, or (at your option) any later ver- --
16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. --
19 -- --
20 -- --
21 -- --
22 -- --
23 -- --
24 -- You should have received a copy of the GNU General Public License and --
25 -- a copy of the GCC Runtime Library Exception along with this program; --
26 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
27 -- <http://www.gnu.org/licenses/>. --
28 -- --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
31 -- --
32 -- The port of GNARL to bare board targets was initially developed by the --
33 -- Real-Time Systems Group at the Technical University of Madrid. --
34 -- --
35 ------------------------------------------------------------------------------
36
37 -- This package defines basic parameters used by the low level tasking system
38
39 -- This is the XtratuM version of this package
40
41 pragma Restrictions (No_Elaboration_Code);
42
43 package System.BB.Parameters is
44 pragma Pure;
45
46 --------------------
47 -- Hardware clock --
48 --------------------
49
50 Clock_Frequency : constant := 1_000_000; -- Hertz
51 -- Frequency of the system clock (XtratuM resolution is 1 microsecond)
52
53 ----------------
54 -- Interrupts --
55 ----------------
56
57 -- These definitions are in this package to isolate target dependencies
58
59 Number_Of_Interrupt_ID : constant := 15 + 32;
60 -- Number of interrupts in XtratuM. There are 15 hardware interrupts (as
61 -- expected for SPARC architectures) plus other 32 for extended interrupts
62 -- corresponding to traps 0xE0 to 0xFF.
63
64 Trap_Vectors : constant := 256;
65 -- The SPARC arquitecture supports 256 vectors (the last 32 for XtratuM
66 -- extended interrupts).
67
68 ------------------------
69 -- Context Management --
70 ------------------------
71
72 -- The SPARC processor needs to save:
73
74 -- * 18 integer registers of 32 bits (7 global, 8 output, PSR, Y, and WIM)
75 -- for normal processing
76
77 -- * 33 floating point registers of 32 bits
78
79 -- * the number of register windows saved to the stack
80 -- (the input and local registers are saved to the stack).
81
82 -- * interrupt nesting level corresponding to the task
83
84 -- * for LEON, to slots for the Cache Control Register
85
86 -- This would be 55 slots for LEON/LEON3 and 53 otherwise, but this need to
87 -- be rounded up to an even number to allow more efficient access.
88
89 -- For LEON, we store the Cache Control Register to be able to keep the
90 -- cache status per task. We keep the base Cache Control Register (which
91 -- is not affected by automatic changes related to the freeze-on-interrupt
92 -- capability) and the actual Cache Control Register (the one directly
93 -- extracted from the hardware).
94
95 Base_CCR_Context_Index : constant := 53;
96 CCR_Context_Index : constant := 54;
97
98 Context_Buffer_Capacity : constant := 56;
99
100 ------------
101 -- Stacks --
102 ------------
103
104 Interrupt_Stack_Size : constant := 4 * 1024;
105 -- Size of each of the interrupt stacks in bytes
106
107 ----------
108 -- CPUS --
109 ----------
110
111 Max_Number_Of_CPUs : constant := 1;
112 -- Maximum number of CPUs
113
114 Multiprocessor : constant Boolean := Max_Number_Of_CPUs /= 1;
115 -- Are we on a multiprocessor board?
116
117 end System.BB.Parameters;