xref: /openbmc/linux/arch/mips/bcm47xx/prom.c (revision b6dcefde)
1 /*
2  *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
3  *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
4  *
5  *  This program is free software; you can redistribute  it and/or modify it
6  *  under  the terms of  the GNU General  Public License as published by the
7  *  Free Software Foundation;  either version 2 of the  License, or (at your
8  *  option) any later version.
9  *
10  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
11  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
12  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
13  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
14  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
15  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
16  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
17  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
18  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
19  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
20  *
21  *  You should have received a copy of the  GNU General Public License along
22  *  with this program; if not, write  to the Free Software Foundation, Inc.,
23  *  675 Mass Ave, Cambridge, MA 02139, USA.
24  */
25 
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/kernel.h>
29 #include <linux/spinlock.h>
30 #include <asm/bootinfo.h>
31 #include <asm/fw/cfe/cfe_api.h>
32 #include <asm/fw/cfe/cfe_error.h>
33 
34 static int cfe_cons_handle;
35 
36 const char *get_system_type(void)
37 {
38 	return "Broadcom BCM47XX";
39 }
40 
41 void prom_putchar(char c)
42 {
43 	while (cfe_write(cfe_cons_handle, &c, 1) == 0)
44 		;
45 }
46 
47 static __init void prom_init_cfe(void)
48 {
49 	uint32_t cfe_ept;
50 	uint32_t cfe_handle;
51 	uint32_t cfe_eptseal;
52 	int argc = fw_arg0;
53 	char **envp = (char **) fw_arg2;
54 	int *prom_vec = (int *) fw_arg3;
55 
56 	/*
57 	 * Check if a loader was used; if NOT, the 4 arguments are
58 	 * what CFE gives us (handle, 0, EPT and EPTSEAL)
59 	 */
60 	if (argc < 0) {
61 		cfe_handle = (uint32_t)argc;
62 		cfe_ept = (uint32_t)envp;
63 		cfe_eptseal = (uint32_t)prom_vec;
64 	} else {
65 		if ((int)prom_vec < 0) {
66 			/*
67 			 * Old loader; all it gives us is the handle,
68 			 * so use the "known" entrypoint and assume
69 			 * the seal.
70 			 */
71 			cfe_handle = (uint32_t)prom_vec;
72 			cfe_ept = 0xBFC00500;
73 			cfe_eptseal = CFE_EPTSEAL;
74 		} else {
75 			/*
76 			 * Newer loaders bundle the handle/ept/eptseal
77 			 * Note: prom_vec is in the loader's useg
78 			 * which is still alive in the TLB.
79 			 */
80 			cfe_handle = prom_vec[0];
81 			cfe_ept = prom_vec[2];
82 			cfe_eptseal = prom_vec[3];
83 		}
84 	}
85 
86 	if (cfe_eptseal != CFE_EPTSEAL) {
87 		/* too early for panic to do any good */
88 		printk(KERN_ERR "CFE's entrypoint seal doesn't match.");
89 		while (1) ;
90 	}
91 
92 	cfe_init(cfe_handle, cfe_ept);
93 }
94 
95 static __init void prom_init_console(void)
96 {
97 	/* Initialize CFE console */
98 	cfe_cons_handle = cfe_getstdhandle(CFE_STDHANDLE_CONSOLE);
99 }
100 
101 static __init void prom_init_cmdline(void)
102 {
103 	static char buf[COMMAND_LINE_SIZE] __initdata;
104 
105 	/* Get the kernel command line from CFE */
106 	if (cfe_getenv("LINUX_CMDLINE", buf, COMMAND_LINE_SIZE) >= 0) {
107 		buf[COMMAND_LINE_SIZE - 1] = 0;
108 		strcpy(arcs_cmdline, buf);
109 	}
110 
111 	/* Force a console handover by adding a console= argument if needed,
112 	 * as CFE is not available anymore later in the boot process. */
113 	if ((strstr(arcs_cmdline, "console=")) == NULL) {
114 		/* Try to read the default serial port used by CFE */
115 		if ((cfe_getenv("BOOT_CONSOLE", buf, COMMAND_LINE_SIZE) < 0)
116 		    || (strncmp("uart", buf, 4)))
117 			/* Default to uart0 */
118 			strcpy(buf, "uart0");
119 
120 		/* Compute the new command line */
121 		snprintf(arcs_cmdline, COMMAND_LINE_SIZE, "%s console=ttyS%c,115200",
122 			 arcs_cmdline, buf[4]);
123 	}
124 }
125 
126 static __init void prom_init_mem(void)
127 {
128 	unsigned long mem;
129 
130 	/* Figure out memory size by finding aliases.
131 	 *
132 	 * We should theoretically use the mapping from CFE using cfe_enummem().
133 	 * However as the BCM47XX is mostly used on low-memory systems, we
134 	 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
135 	 * functions stop to work at some point during the boot, we should only
136 	 * call them at the beginning of the boot.
137 	 */
138 	for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
139 		if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
140 		    *(unsigned long *)(prom_init))
141 			break;
142 	}
143 
144 	/* Ignoring the last page when ddr size is 128M. Cached
145 	 * accesses to last page is causing the processor to prefetch
146 	 * using address above 128M stepping out of the ddr address
147 	 * space.
148 	 */
149 	if (mem == 0x8000000)
150 		mem -= 0x1000;
151 
152 	add_memory_region(0, mem, BOOT_MEM_RAM);
153 }
154 
155 void __init prom_init(void)
156 {
157 	prom_init_cfe();
158 	prom_init_console();
159 	prom_init_cmdline();
160 	prom_init_mem();
161 }
162 
163 void __init prom_free_prom_memory(void)
164 {
165 }
166 
167