gpllib: Add disk library

This library features read and write operations, as well as geometry detection.
It will prevent duplicating code between several modules (e.g. hdt and chain.c32).

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/com32/gpllib/disk/ata.c b/com32/gpllib/disk/ata.c
new file mode 100644
index 00000000..f1716ffa
--- /dev/null
+++ b/com32/gpllib/disk/ata.c
@@ -0,0 +1,59 @@
+/**
+ *      ata_id_string - Convert IDENTIFY DEVICE page into string
+ *      @id: IDENTIFY DEVICE results we will examine
+ *      @s: string into which data is output
+ *      @ofs: offset into identify device page
+ *      @len: length of string to return. must be an even number.
+ *
+ *      The strings in the IDENTIFY DEVICE page are broken up into
+ *      16-bit chunks.  Run through the string, and output each
+ *      8-bit chunk linearly, regardless of platform.
+ *
+ *      LOCKING:
+ *      caller.
+ */
+void ata_id_string(const uint16_t * id, unsigned char *s,
+       unsigned int ofs, unsigned int len)
+{
+  unsigned int c;
+
+  while (len > 0) {
+    c = id[ofs] >> 8;
+    *s = c;
+    s++;
+
+    c = id[ofs] & 0xff;
+    *s = c;
+    s++;
+
+    ofs++;
+    len -= 2;
+  }
+}
+
+/**
+ *      ata_id_c_string - Convert IDENTIFY DEVICE page into C string
+ *      @id: IDENTIFY DEVICE results we will examine
+ *      @s: string into which data is output
+ *      @ofs: offset into identify device page
+ *      @len: length of string to return. must be an odd number.
+ *
+ *      This function is identical to ata_id_string except that it
+ *      trims trailing spaces and terminates the resulting string with
+ *      null.  @len must be actual maximum length (even number) + 1.
+ *
+ *      LOCKING:
+ *      caller.
+ */
+void ata_id_c_string(const uint16_t * id, unsigned char *s,
+         unsigned int ofs, unsigned int len)
+{
+  unsigned char *p;
+
+  ata_id_string(id, s, ofs, len - 1);
+
+  p = s + strnlen(s, len - 1);
+  while (p > s && p[-1] == ' ')
+    p--;
+  *p = '\0';
+}