Merge branch 'bob' of https://repo.or.cz/RPi-MMU-example into alice

# Conflicts:
#	.gitignore
#	PL0_test.ld
#	demo_functionality.c
#	interrupt_vector.S
#	interrupts.c
#	kernel.c
#	memory.h

1 files changed, 119 insertions, 0 deletions

diff --git a/strings.c b/strings.c
new file mode 100644
index 0000000..368d7dc
--- /dev/null
+++ b/strings.c
@@ -0,0 +1,119 @@
+#include "strings.h"
+
+void uint32_to_dec(uint32_t number, char buf[10])
+{
+  for (int i = 0; i < 10; i++)
+    {
+      buf[10 - 1 - i] = '0' + (number % 10);
+      number /= 10;
+    }
+}
+
+void uint32_to_hex(uint32_t number, char buf[8])
+{
+  for (int i = 0; i < 8; i++)
+    {
+      unsigned char quadbit = (number >> ((8 - i - 1) * 4)) & 0xf;
+      buf[i] =  quadbit > 9 ? quadbit - 10 + 'a' : quadbit + '0';
+    }
+}
+
+void uint32_to_bin(uint32_t number, char buf[32])
+{
+  for (int i = 0; i < 32; i++)
+    buf[i] = ((number >> (32 - i - 1)) & 1) ? '1' : '0';
+}
+
+void uint32_to_decstring(uint32_t number, char buf[11])
+{
+  uint32_to_dec(number, buf);
+  buf[10] = '\0';
+}
+
+void uint32_to_hexstring(uint32_t number, char buf[9])
+{
+  uint32_to_hex(number, buf);
+  buf[8] = '\0';
+}
+
+void uint32_to_binstring(uint32_t number, char buf[33])
+{
+  uint32_to_bin(number, buf);
+  buf[32] = '\0';
+}
+
+void trim_0s(char string[])
+{
+  size_t i;
+  for (i = 0; string[i] == '0'; i++);
+  
+  size_t j = 0;
+  
+  if (!string[i])
+    string[j++] = string[--i];
+
+  do
+    string[j] = string[i + j];
+  while (string[j++]);
+}
+
+void uint32_to_decstringt(uint32_t number, char buf[11])
+{
+  uint32_to_decstring(number, buf);
+  trim_0s(buf);
+}
+
+void uint32_to_hexstringt(uint32_t number, char buf[9])
+{
+  uint32_to_hexstring(number, buf);
+  trim_0s(buf);
+}
+
+size_t strlen(char string[])
+{
+  size_t len;
+
+  for (len = 0; string[len]; len++);
+
+  return len;
+}
+
+void memcpy(void *dst, void *src, size_t nbytes)
+{
+  size_t iter;
+
+  // copying by word is faster than by byte,
+  // but can easily cause alignment faults, so we resign from it...
+  for (iter = 0; iter < nbytes ; iter++)
+    ((volatile uint8_t*) dst)[iter] = ((uint8_t*) src)[iter];
+}
+
+// keep in mind memset is also needed for array initialization, like
+// uint32_t buf[16] = {0};
+// gcc compiles this to memset call
+
+void *memset(void *s, int c, size_t n)
+{
+  volatile char *mem = s;
+  
+  for (size_t i = 0; i < n; i++)
+    mem[i] = c;
+  
+  return s;
+}
+
+char *strcat(char *dst, const char *src)
+{
+  char *where_to_append;
+
+  for (where_to_append = dst; *where_to_append; where_to_append++);
+  
+  size_t i;
+  
+  for (i = 0; src[i]; i++)
+    ((char volatile*) where_to_append)[i] = src[i];
+
+  ((char volatile*) where_to_append)[i] = '\0';
+
+  return dst;
+}