Support relocatable reGNUal

diff --git a/ChangeLog b/ChangeLog
index c1108fb..5c20459 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2013-03-15  Niibe Yutaka  <gniibe@fsij.org>
 
+       Support relocatable reGNUal.
+
+       * src/neug.ld.in (_regnual_start): Now, it's just '.'.
+       * src/main.c (calculate_regnual_entry_address): New.
+       (main): Use calculate_regnual_entry_address for entry point.
+
        New USB stack.
 
        * src/main.c (device_desc, config_desc, string_descs): Remove.

diff --git a/src/main.c b/src/main.c
index 11dc8e3..46f63ef 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -696,6 +696,24 @@ static void copy_to_tx (uint32_t v, int i)
   usb_lld_txcpy (&v, ENDP1, i * 4, 4);
 }
 
+/*
+ * In Gnuk 1.0.[12], reGNUal was not relocatable.
+ * Now, it's relocatable, but we need to calculate its entry address
+ * based on it's pre-defined address.
+ */
+#define REGNUAL_START_ADDRESS_COMPATIBLE 0x20001400
+static uint32_t
+calculate_regnual_entry_address (const uint8_t *addr)
+{
+  const uint8_t *p = addr + 4;
+  uint32_t v = p[0] + (p[1] << 8) + (p[2] << 16) + (p[3] << 24);
+
+  v -= REGNUAL_START_ADDRESS_COMPATIBLE;
+  v += (uint32_t)addr;
+  return v;
+}
+
+
 /*
  * Entry point.
  *
@@ -704,6 +722,8 @@ static void copy_to_tx (uint32_t v, int i)
 int
 main (int argc, char **argv)
 {
+  uint32_t entry;
+
   (void)argc;
   (void)argv;
 
@@ -830,6 +850,7 @@ main (int argc, char **argv)
   port_disable ();
   /* Set vector */
   SCB->VTOR = (uint32_t)&_regnual_start;
+  entry = calculate_regnual_entry_address (&_regnual_start);
 #ifdef DFU_SUPPORT
 #define FLASH_SYS_START_ADDR 0x08000000
 #define FLASH_SYS_END_ADDR (0x08000000+0x1000)
@@ -848,12 +869,12 @@ main (int argc, char **argv)
     flash_write (FLASH_SYS_START_ADDR, &_sys, 0x1000);
 
     /* Leave NeuG to exec reGNUal */
-    (*func) (*((void (**)(void))(&_regnual_start+4)));
+    (*func) ((void (*)(void))entry);
     for (;;);
   }
 #else
   /* Leave NeuG to exec reGNUal */
-  flash_erase_all_and_exec (*((void (**)(void))(&_regnual_start+4)));
+  flash_erase_all_and_exec ((void (*)(void))entry);
 #endif
 
   /* Never reached */

diff --git a/src/neug.ld.in b/src/neug.ld.in
index 4568914..d2ddc4f 100644 (file)
--- a/src/neug.ld.in
+++ b/src/neug.ld.in
@@ -163,8 +163,8 @@ SECTIONS
     PROVIDE(end = .);
     _end            = .;
     . = ALIGN(512);
-    /* it is at offset 0x1400 from ram start */
-    _regnual_start = __ram_start__ + 0x1400;
+    /* reGNUal is now relocatable, it's OK not using fixed address. */
+    _regnual_start = .;
 
     .fill_ffff :
     {