source: trunk/hal/tsar_mips32/core/hal_kentry.h @ 406

Last change on this file since 406 was 406, checked in by alain, 4 years ago

This version executed successfully the user "init" process on a mono-processor TSAR architecture.

File size: 4.3 KB
Line 
1/*
2 * hal_kentry.h - MIPS32 registers mnemonics
3 *
4 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
5 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
6 *
7 * This file is part of ALMOS-kernel.
8 *
9 * ALMOS-kernel is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2.0 of the License.
12 *
13 * ALMOS-kernel is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#ifndef _HAL_KENTRY_H_
24#define _HAL_KENTRY_H_
25
26//////////////////////////////////////////////////////////////////////////////////////////
27// This file defines the MIPS32 specific mnemonics to access the "uzone", that is
28// a fixed size array of 32 bits integers, used by the kentry function to save/restore
29// the MIPS32 CPU registers, at each exception / interruption / syscall.
30// It also defines several initial values for the SR register.
31//
32// This file is included in the hal_kentry.S, hal_syscall.c, hal_exception.c,
33// and hal_context.c files.
34//////////////////////////////////////////////////////////////////////////////////////////
35
36
37/****************************************************************************************
38 * This structure defines the cpu_uzone for TSAR MIPS32, as well as the
39 *  mnemonics used by the hal_kentry assembly code.
40 ***************************************************************************************/
41
42#define      UZ_MODE         0    /* c2_mode */             
43#define      UZ_AT           1
44#define      UZ_V0           2
45#define      UZ_V1           3
46#define      UZ_A0           4
47#define      UZ_A1           5
48#define      UZ_A2           6
49#define      UZ_A3           7
50#define      UZ_T0           8
51#define      UZ_T1           9
52#define      UZ_T2           10
53#define      UZ_T3           11
54#define      UZ_T4           12
55#define      UZ_T5           13
56#define      UZ_T6           14
57#define      UZ_T7           15
58#define      UZ_T8           16
59#define      UZ_T9           17
60#define      UZ_S0           18
61#define      UZ_S1           19
62#define      UZ_S2           20
63#define      UZ_S3           21
64#define      UZ_S4           22
65#define      UZ_S5           23
66#define      UZ_S6           24
67#define      UZ_S7           25
68#define      UZ_S8           26
69#define      UZ_GP           27
70#define      UZ_RA           28
71#define      UZ_EPC          29   /* c0_epc */
72#define      UZ_CR           30   /* c0_cr */
73#define      UZ_SP           31
74#define      UZ_SR           32   /* c0_sr */
75#define      UZ_LO           33
76#define      UZ_HI           34
77
78#define      UZ_REGS         35
79
80/*************************************************************************************
81 * The hal_kentry_enter() function is the unique kernel entry point in case of
82 * exception, interrupt, or syscall for the TSAR_MIPS32 architecture. 
83 *
84 * When we enter the kernel, we test the status register:
85 * - If the core is in user mode, we desactivate the MMU, and we save
86 *   the core context in the uzone of the calling thread descriptor.
87 * - If the core is already in kernel mode (in case of interrupt),
88 *   we save the context in the kernel stack.
89 * - In both cases, we increment the cores_in_kernel variable,
90 *   and we call the relevant exception/interrupt/syscall handler
91 *
92 * When we exit the kernel after handler execution:
93 * - we restore the core context from the uzone and return to user space,
94 *   calling the hal_kentry_eret()
95 ************************************************************************************/
96void hal_kentry_enter();
97
98/*************************************************************************************
99 * The hal_kentry_eret() function contains only the assembly "eret" instruction,
100 * that and the EXL bit in the c0_sr register, and jump to the address
101 * contained in the c0_epc register.
102 * ************************************************************************************/
103void hal_kentry_eret();
104
105#endif  /* _HAL_KENTRY_H_ */
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