Linux Kernel  3.7.1
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prom.c
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1 /*
2  * Copyright (c) 2011 Zhang, Keguang <[email protected]>
3  *
4  * Modified from arch/mips/pnx833x/common/prom.c.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2 of the License, or (at your
9  * option) any later version.
10  */
11 
12 #include <linux/serial_reg.h>
13 #include <asm/bootinfo.h>
14 
15 #include <loongson1.h>
16 #include <prom.h>
17 
19 char **prom_argv, **prom_envp;
20 unsigned long memsize, highmemsize;
21 
22 char *prom_getenv(char *envname)
23 {
24  char **env = prom_envp;
25  int i;
26 
27  i = strlen(envname);
28 
29  while (*env) {
30  if (strncmp(envname, *env, i) == 0 && *(*env+i) == '=')
31  return *env + i + 1;
32  env++;
33  }
34 
35  return 0;
36 }
37 
38 static inline unsigned long env_or_default(char *env, unsigned long dfl)
39 {
40  char *str = prom_getenv(env);
41  return str ? simple_strtol(str, 0, 0) : dfl;
42 }
43 
45 {
46  char *c = &(arcs_cmdline[0]);
47  int i;
48 
49  for (i = 1; i < prom_argc; i++) {
50  strcpy(c, prom_argv[i]);
51  c += strlen(prom_argv[i]);
52  if (i < prom_argc-1)
53  *c++ = ' ';
54  }
55  *c = 0;
56 }
57 
58 void __init prom_init(void)
59 {
61  prom_argv = (char **)fw_arg1;
62  prom_envp = (char **)fw_arg2;
63 
65 
66  memsize = env_or_default("memsize", DEFAULT_MEMSIZE);
67  highmemsize = env_or_default("highmemsize", 0x0);
68 }
69 
71 {
72 }
73 
74 #define PORT(offset) (u8 *)(KSEG1ADDR(LS1X_UART0_BASE + offset))
75 
76 void __init prom_putchar(char c)
77 {
78  int timeout;
79 
80  timeout = 1024;
81 
82  while (((readb(PORT(UART_LSR)) & UART_LSR_THRE) == 0)
83  && (timeout-- > 0))
84  ;
85 
86  writeb(c, PORT(UART_TX));
87 }