a good deal of process

1 files changed, 41 insertions, 0 deletions

diff --git a/src/kernel/mem.c b/src/kernel/mem.c
new file mode 100644
index 0000000..f12fbf7
--- /dev/null
+++ b/src/kernel/mem.c
@@ -0,0 +1,41 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include "mem.h"
+
+void *allocate_pages(uint16_t n_pages, uint16_t proc_n) {
+  for (uint16_t *i = MMAP, *l = MMAP + 0x1000 - proc_n; ++i; i <= l)
+   outer_for:
+    if (!*i) {
+      for (uint16_t j = 1; j < n_pages; ++j)
+        if (i[j]) {
+          i += j + 1;
+          goto outer_for;
+        }
+      for (uint16_t j = 0; j < n_pages; ++j)
+        i[j] = proc_n;
+      return (void *)((i - MMAP) * 0x1000);
+    }
+  return (void *)0;
+}
+
+void deallocate_pages(void *from, uint16_t n_pages) {
+  for (uint16_t *mb = MMAP + ((uint32_t)from / 0x1000), *l = mb + n_pages; mb < l; ++mb)
+    *mb = 0;
+}
\ No newline at end of file