Large reorganization.

What was in core/ is now moved to arch/stm34l4xxx/peripherals.  This new
directory is *supposed to* to contain raw header files defining just the
pertinent register structures for the various peripherals.  Peripheral
management belongs somewhere in the new `kern/..` directories. This is
not completely the case at the moment, so more refactoring needs to be
done.

What was sitting in the root has now been moved into the kern/
directory. The kern/ directory is to contain everything else
other than raw device register definitions. The root of the kern/
tree is reserved for standard library-esque headers.

The kern/<peripheral> directory contains management systems for that
peripheral. (At the moment DMA is the only peripheral with a decent
management system.) Preferably these peripheral systems should only
include their correlating header in arch/stm34l4xxx/peripherals, and
use other management systems for handling other peripherals rather
than manipulating their raw registers directly. (Though this ideal
will require much more critical mass of management systems.)

1 files changed, 56 insertions, 0 deletions

diff --git a/02-usart/src/kern/lib.c b/02-usart/src/kern/lib.c
new file mode 100644
index 0000000..88188cc
--- /dev/null
+++ b/02-usart/src/kern/lib.c
@@ -0,0 +1,56 @@
+#include "kern/lib.h"
+
+#define nybble_to_hex(n) \
+  ((n) < 10 ? 0x30 + (n) : ('A' + ((n) - 10)))
+
+void hexify(uint32_t v, char* into)
+{
+  into += 8;
+
+  *(into--) = 0;
+
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *(into--) = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+  *into = nybble_to_hex(v & 0x0F);
+  v >>= 4;
+}
+
+void decimalify(int v, char* into)
+{
+  int c = 0;
+  int i;
+
+  if (v == 0) {
+    *(into ++) = '0';
+    *into = 0;
+    return;
+  } else {
+    while (v > 0) {
+      *(into ++) = 0x30 + (v % 10);
+      v /= 10;
+      ++ c;
+    }
+  }
+  *into = 0;
+
+  into -= c;
+  for (i = 0; i < c / 2; ++ i) {
+    char tmp = into[i];
+    into[i] = into[c - i - 1];
+    into[c - i - 1] = tmp;
+  }
+
+}