libc: provide the fxlibc HAL

See 8cedf41 in fxlibc for rationale.

CMakeLists.txt

@@ -23,6 +23,8 @@ endif()
 configure_file(include/gint/config.h.in include/gint/config.h)
 
 set(SOURCES
+  # Hardware Abstraction Layer for the standard library
+  src/fxlibc_hal.c
   # Clock Pulse Generator driver
   src/cpg/cpg.c
   src/cpg/overclock.c

src/fxlibc_hal.c

@@ -0,0 +1,40 @@
+/* Hardware Abstraction Layer (HAL) implementation for fxlibc. We can group
+   this in a single file because LTO will prune away unused functions. */
+
+#include <fxlibc/hal.h>
+#include <gint/rtc.h>
+#include <gint/kmalloc.h>
+#include <errno.h>
+
+void *fxlibc_hal_malloc(size_t size)
+{
+    return kmalloc(size, NULL);
+}
+
+void fxlibc_hal_free(void *ptr)
+{
+    return kfree(ptr);
+}
+
+void *fxlibc_hal_realloc(void *ptr, size_t size)
+{
+    return krealloc(ptr, size);
+}
+
+void fxlibc_hal_rawtime(struct tm *tm)
+{
+    rtc_time_t rtc;
+    rtc_get_time(&rtc);
+    tm->tm_sec   = rtc.seconds;
+    tm->tm_min   = rtc.minutes;
+    tm->tm_hour  = rtc.hours;
+    tm->tm_mday  = rtc.month_day;
+    tm->tm_mon   = rtc.month;
+    tm->tm_year  = rtc.year - 1900;
+    tm->tm_isdst = 0;
+}
+
+clock_t fxlibc_hal_clock(void)
+{
+    return (CLOCKS_PER_SEC * (uint64_t)rtc_ticks()) / 128;
+}