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-rw-r--r--com32/sysdump/ctime.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/com32/sysdump/ctime.c b/com32/sysdump/ctime.c
new file mode 100644
index 00000000..5af85666
--- /dev/null
+++ b/com32/sysdump/ctime.c
@@ -0,0 +1,70 @@
+#include <com32.h>
+#include <string.h>
+#include "ctime.h"
+
+static uint8_t frombcd(uint8_t v)
+{
+ uint8_t a = v & 0x0f;
+ uint8_t b = v >> 4;
+
+ return a + b*10;
+}
+
+uint32_t posix_time(void)
+{
+ /* Days from March 1 for a specific month, starting in March */
+ static const unsigned int yday[12] =
+ { 0, 31, 61, 92, 122, 153, 184, 214, 245, 275, 306, 337 };
+ com32sys_t ir, d0, d1, t0;
+ unsigned int c, y, mo, d, h, m, s;
+ uint32_t t;
+
+ memset(&ir, 0, sizeof ir);
+
+ ir.eax.b[1] = 0x04;
+ __intcall(0x1A, &ir, &d0);
+
+ ir.eax.b[1] = 0x02;
+ __intcall(0x1A, &ir, &t0);
+
+ ir.eax.b[1] = 0x04;
+ __intcall(0x1A, &ir, &d1);
+
+ if (t0.ecx.b[1] < 0x12)
+ d0 = d1;
+
+ c = frombcd(d0.ecx.b[1]);
+ y = frombcd(d0.ecx.b[0]);
+ mo = frombcd(d0.edx.b[1]);
+ d = frombcd(d0.edx.b[0]);
+
+ h = frombcd(t0.ecx.b[1]);
+ m = frombcd(t0.ecx.b[0]);
+ s = frombcd(t0.edx.b[1]);
+
+ /* We of course have no idea about the timezone, so ignore it */
+
+ /*
+ * Look for impossible dates... this code was written in 2010, so
+ * assume any century less than 20 is just broken.
+ */
+ if (c < 20)
+ c = 20;
+ y += c*100;
+
+ /* Consider Jan and Feb as the last months of the previous year */
+ if (mo < 3) {
+ y--;
+ mo += 12;
+ }
+
+ t = y*365 + y/4 - y/100 + y/400 + yday[mo-3] + d - 719469;
+ t *= 24;
+ t += h;
+ t *= 60;
+ t += m;
+ t *= 60;
+ t += s;
+
+ return t;
+}