diff options
Diffstat (limited to 'arch/x86/kernel/bootflag.c')
| -rw-r--r-- | arch/x86/kernel/bootflag.c | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/arch/x86/kernel/bootflag.c b/arch/x86/kernel/bootflag.c index 0b9860530a6b..30f25a75fe28 100644 --- a/arch/x86/kernel/bootflag.c +++ b/arch/x86/kernel/bootflag.c @@ -1,8 +1,6 @@ /* * Implement 'Simple Boot Flag Specification 2.0' */ - - #include <linux/types.h> #include <linux/kernel.h> #include <linux/init.h> @@ -14,40 +12,38 @@ #include <linux/mc146818rtc.h> - #define SBF_RESERVED (0x78) #define SBF_PNPOS (1<<0) #define SBF_BOOTING (1<<1) #define SBF_DIAG (1<<2) #define SBF_PARITY (1<<7) - int sbf_port __initdata = -1; /* set via acpi_boot_init() */ - static int __init parity(u8 v) { int x = 0; int i; - - for(i=0;i<8;i++) - { - x^=(v&1); - v>>=1; + + for (i = 0; i < 8; i++) { + x ^= (v & 1); + v >>= 1; } + return x; } static void __init sbf_write(u8 v) { unsigned long flags; - if(sbf_port != -1) - { + + if (sbf_port != -1) { v &= ~SBF_PARITY; - if(!parity(v)) - v|=SBF_PARITY; + if (!parity(v)) + v |= SBF_PARITY; - printk(KERN_INFO "Simple Boot Flag at 0x%x set to 0x%x\n", sbf_port, v); + printk(KERN_INFO "Simple Boot Flag at 0x%x set to 0x%x\n", + sbf_port, v); spin_lock_irqsave(&rtc_lock, flags); CMOS_WRITE(v, sbf_port); @@ -57,33 +53,41 @@ static void __init sbf_write(u8 v) static u8 __init sbf_read(void) { - u8 v; unsigned long flags; - if(sbf_port == -1) + u8 v; + + if (sbf_port == -1) return 0; + spin_lock_irqsave(&rtc_lock, flags); v = CMOS_READ(sbf_port); spin_unlock_irqrestore(&rtc_lock, flags); + return v; } static int __init sbf_value_valid(u8 v) { - if(v&SBF_RESERVED) /* Reserved bits */ + if (v & SBF_RESERVED) /* Reserved bits */ return 0; - if(!parity(v)) + if (!parity(v)) return 0; + return 1; } static int __init sbf_init(void) { u8 v; - if(sbf_port == -1) + + if (sbf_port == -1) return 0; + v = sbf_read(); - if(!sbf_value_valid(v)) - printk(KERN_WARNING "Simple Boot Flag value 0x%x read from CMOS RAM was invalid\n",v); + if (!sbf_value_valid(v)) { + printk(KERN_WARNING "Simple Boot Flag value 0x%x read from " + "CMOS RAM was invalid\n", v); + } v &= ~SBF_RESERVED; v &= ~SBF_BOOTING; @@ -92,7 +96,7 @@ static int __init sbf_init(void) v |= SBF_PNPOS; #endif sbf_write(v); + return 0; } - module_init(sbf_init); |