Hello all ,
My embeded board hardware configuration is like this :
# cat /proc/cpuinfo
Processor : XScale-IXP425/IXC1100 rev 1 (v5b)
BogoMIPS : 266.24
Features : swp half thumb fastmult edsp Hardware : Intel IXDP425 Development Platform Revision : 0000 Serial : 0000000000000000 Through reading datasheet of ixp4xx ,I know it has own watchdog functions , please see attchment :15 Timer I find a driver by goole , see attachment . Watchdog timer counter is 32 bit register , its max value is 2<<32 -1 #define TIMER_FREQ 66000000 /* 66 MHZ timer */ #define TIMER_KEY 0x482e #define TIMER_MARGIN 60 /* (secs) Default is 1 minute */ //I want to modify it ,I find its max value is 65 static int ixp425_margin = TIMER_MARGIN; /* in seconds */ static int ixp425wdt_users; //static int pre_margin; //IXP425 CPU 's watch dog timer is 32 bit , //so I define it to be unsigned int --bob static unsigned int pre_margin; pre_margin = TIMER_FREQ * TIMER_MARGIN *IXP425_OSWT = pre_margin; if I need one minutes , *IXP425_OSWT = 66000000 * 60 = 396000000 ,not overflow if I need two minutes , *IXP425_OSWT = 66000000 * 120 = 792000000 ( which has been > 2<<32-1 , overflow So I compute the max time I can set : T_max = 2<<32-1 / 66000000 = 65 seconds 。 -------------------- My question: if need more seconds ( for example , 5 minutes ) ,what should I do ? I have a method based on datasheet (ixp4xx) ,but I don't know if it will successed when system crash How can I do to break the limit of hardware ? Thanks ahead ! -- Best Regards bob
ixp425_wdt.c
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