xref: /openbmc/u-boot/post/lib_powerpc/b.c (revision efc05ae1)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 
26 /*
27  * CPU test
28  * Branch instructions:		b, bl, bc
29  *
30  * The first 2 instructions (b, bl) are verified by jumping
31  * to a fixed address and checking whether control was transfered
32  * to that very point. For the bl instruction the value of the
33  * link register is checked as well (using mfspr).
34  * To verify the bc instruction various combinations of the BI/BO
35  * fields, the CTR and the condition register values are
36  * checked. The list of such combinations is pre-built and
37  * linked in U-Boot at build time.
38  */
39 
40 #include <post.h>
41 #include "cpu_asm.h"
42 
43 #if CONFIG_POST & CONFIG_SYS_POST_CPU
44 
45 extern void cpu_post_exec_11 (ulong *code, ulong *res, ulong op1);
46 extern void cpu_post_exec_31 (ulong *code, ulong *ctr, ulong *lr, ulong *jump,
47     ulong cr);
48 
49 static int cpu_post_test_bc (ulong cmd, ulong bo, ulong bi,
50     int pjump, int decr, int link, ulong pctr, ulong cr)
51 {
52     int ret = 0;
53     ulong lr = 0;
54     ulong ctr = pctr;
55     ulong jump;
56 
57     unsigned long code[] =
58     {
59 	ASM_MTCR(6),
60 	ASM_MFLR(6),
61 	ASM_MTCTR(3),
62 	ASM_MTLR(4),
63 	ASM_LI(5, 1),
64 	ASM_3O(cmd, bo, bi, 8),
65 	ASM_LI(5, 0),
66 	ASM_MFCTR(3),
67 	ASM_MFLR(4),
68 	ASM_MTLR(6),
69 	ASM_BLR,
70     };
71 
72     cpu_post_exec_31 (code, &ctr, &lr, &jump, cr);
73 
74     if (ret == 0)
75 	ret = pjump == jump ? 0 : -1;
76     if (ret == 0)
77     {
78 	if (decr)
79 	    ret = pctr == ctr + 1 ? 0 : -1;
80 	else
81 	    ret = pctr == ctr ? 0 : -1;
82     }
83     if (ret == 0)
84     {
85 	if (link)
86 	    ret = lr == (ulong) code + 24 ? 0 : -1;
87 	else
88 	    ret = lr == 0 ? 0 : -1;
89     }
90 
91     return ret;
92 }
93 
94 int cpu_post_test_b (void)
95 {
96     int ret = 0;
97     unsigned int i;
98     int flag = disable_interrupts();
99 
100     if (ret == 0)
101     {
102 	ulong code[] =
103 	{
104 	   ASM_MFLR(4),
105 	   ASM_MTLR(3),
106 	   ASM_B(4),
107 	   ASM_MFLR(3),
108 	   ASM_MTLR(4),
109 	   ASM_BLR,
110 	};
111 	ulong res;
112 
113 	cpu_post_exec_11 (code, &res, 0);
114 
115 	ret = res == 0 ? 0 : -1;
116 
117 	if (ret != 0)
118 	{
119 	    post_log ("Error at b1 test !\n");
120 	}
121     }
122 
123     if (ret == 0)
124     {
125 	ulong code[] =
126 	{
127 	   ASM_MFLR(4),
128 	   ASM_MTLR(3),
129 	   ASM_BL(4),
130 	   ASM_MFLR(3),
131 	   ASM_MTLR(4),
132 	   ASM_BLR,
133 	};
134 	ulong res;
135 
136 	cpu_post_exec_11 (code, &res, 0);
137 
138 	ret = res == (ulong)code + 12 ? 0 : -1;
139 
140 	if (ret != 0)
141 	{
142 	    post_log ("Error at b2 test !\n");
143 	}
144     }
145 
146     if (ret == 0)
147     {
148 	ulong cc, cd;
149 	int cond;
150 	ulong ctr;
151 	int link;
152 
153 	i = 0;
154 
155 	for (cc = 0; cc < 4 && ret == 0; cc++)
156 	{
157 	    for (cd = 0; cd < 4 && ret == 0; cd++)
158 	    {
159 		for (link = 0; link <= 1 && ret == 0; link++)
160 		{
161 		    for (cond = 0; cond <= 1 && ret == 0; cond++)
162 		    {
163 			for (ctr = 1; ctr <= 2 && ret == 0; ctr++)
164 			{
165 			    int decr = cd < 2;
166 			    int cr = cond ? 0x80000000 : 0x00000000;
167 			    int jumpc = cc >= 2 ||
168 					(cc == 0 && !cond) ||
169 					(cc == 1 && cond);
170 			    int jumpd = cd >= 2 ||
171 					(cd == 0 && ctr != 1) ||
172 					(cd == 1 && ctr == 1);
173 			    int jump = jumpc && jumpd;
174 
175 			    ret = cpu_post_test_bc (link ? OP_BCL : OP_BC,
176 				(cc << 3) + (cd << 1), 0, jump, decr, link,
177 				ctr, cr);
178 
179 			    if (ret != 0)
180 			    {
181 				post_log ("Error at b3 test %d !\n", i);
182 			    }
183 
184 			    i++;
185 			}
186 		    }
187 		}
188 	    }
189 	}
190     }
191 
192     if (flag)
193 	enable_interrupts();
194 
195     return ret;
196 }
197 
198 #endif
199