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author | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2012-04-27 02:31:28 +0200 |
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committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2012-04-27 19:23:16 +0200 |
commit | ae5e11d7cd7484343d277fb454fb19fdff34730d (patch) | |
tree | 231aede3dcf80242a4e68e2b4268835f4bf1c5c6 /src/drivers/pc80/mc146818rtc_early.c | |
parent | aee1869fcf6c5eb1616f8c5c5a446c2b2de693e8 (diff) | |
download | coreboot-ae5e11d7cd7484343d277fb454fb19fdff34730d.tar.gz coreboot-ae5e11d7cd7484343d277fb454fb19fdff34730d.tar.bz2 coreboot-ae5e11d7cd7484343d277fb454fb19fdff34730d.zip |
Move top level pc80 directory to drivers/
There is no reason for this to be a top level directory.
Some stuff from lib/ should also be moved to drivers/
Change-Id: I3c2d2e127f7215eadead029cfc7442c22b26814a
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/939
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Diffstat (limited to 'src/drivers/pc80/mc146818rtc_early.c')
-rw-r--r-- | src/drivers/pc80/mc146818rtc_early.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/src/drivers/pc80/mc146818rtc_early.c b/src/drivers/pc80/mc146818rtc_early.c new file mode 100644 index 000000000000..0652f27c47ff --- /dev/null +++ b/src/drivers/pc80/mc146818rtc_early.c @@ -0,0 +1,104 @@ +#include <stdint.h> +#include <pc80/mc146818rtc.h> +#include <fallback.h> +#if CONFIG_USE_OPTION_TABLE +#include "option_table.h" +#endif + +#ifndef CONFIG_MAX_REBOOT_CNT +#error "CONFIG_MAX_REBOOT_CNT not defined" +#endif +#if CONFIG_MAX_REBOOT_CNT > 15 +#error "CONFIG_MAX_REBOOT_CNT too high" +#endif + +static int cmos_error(void) +{ + unsigned char reg_d; + /* See if the cmos error condition has been flagged */ + reg_d = cmos_read(RTC_REG_D); + return (reg_d & RTC_VRT) == 0; +} + +static int cmos_chksum_valid(void) +{ +#if CONFIG_USE_OPTION_TABLE + unsigned char addr; + u16 sum, old_sum; + sum = 0; + /* Compute the cmos checksum */ + for(addr = LB_CKS_RANGE_START; addr <= LB_CKS_RANGE_END; addr++) { + sum += cmos_read(addr); + } + + /* Read the stored checksum */ + old_sum = cmos_read(LB_CKS_LOC) << 8; + old_sum |= cmos_read(LB_CKS_LOC+1); + + return sum == old_sum; +#else + return 0; +#endif +} + + +static inline int last_boot_normal(void) +{ + unsigned char byte; + byte = cmos_read(RTC_BOOT_BYTE); + return (byte & (1 << 1)); +} + +static inline int do_normal_boot(void) +{ + unsigned char byte; + + if (cmos_error() || !cmos_chksum_valid()) { + /* There are no impossible values, no checksums so just + * trust whatever value we have in the the cmos, + * but clear the fallback bit. + */ + byte = cmos_read(RTC_BOOT_BYTE); + byte &= 0x0c; + byte |= CONFIG_MAX_REBOOT_CNT << 4; + cmos_write(byte, RTC_BOOT_BYTE); + } + + /* The RTC_BOOT_BYTE is now o.k. see where to go. */ + byte = cmos_read(RTC_BOOT_BYTE); + + /* Are we in normal mode? */ + if (byte & 1) { + byte &= 0x0f; /* yes, clear the boot count */ + } + + /* Properly set the last boot flag */ + byte &= 0xfc; + if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) { + byte |= (1<<1); + } + + /* Are we already at the max count? */ + if ((byte >> 4) < CONFIG_MAX_REBOOT_CNT) { + byte += 1 << 4; /* No, add 1 to the count */ + } + else { + byte &= 0xfc; /* Yes, put in fallback mode */ + } + + /* Save the boot byte */ + cmos_write(byte, RTC_BOOT_BYTE); + + return (byte & (1<<1)); +} + +unsigned read_option_lowlevel(unsigned start, unsigned size, unsigned def) +{ +#if CONFIG_USE_OPTION_TABLE + unsigned byte; + byte = cmos_read(start/8); + return (byte >> (start & 7U)) & ((1U << size) - 1U); +#else + return def; +#endif +} |