altos: Initial STMF04x support

[fw/altos] / src / stmf0 / ao_boot_chain.c

diff --git a/src/stmf0/ao_boot_chain.c b/src/stmf0/ao_boot_chain.c
new file mode 100644 (file)
index 0000000..bcebf03
--- /dev/null
+++ b/src/stmf0/ao_boot_chain.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_boot.h>
+
+void
+ao_boot_chain(uint32_t *base)
+{
+       uint32_t        sp;
+       uint32_t        pc;
+
+       sp = base[0];
+       pc = base[1];
+       if (0x08000100 <= pc && pc <= 0x08200000 && (pc & 1) == 1) {
+               asm ("mov sp, %0" : : "r" (sp));
+               asm ("mov lr, %0" : : "r" (pc));
+               asm ("bx lr");
+       }
+}
+
+#define AO_BOOT_SIGNAL 0x5a5aa5a5
+#define AO_BOOT_CHECK  0xc3c33c3c
+
+struct ao_boot {
+       uint32_t        *base;
+       uint32_t        signal;
+       uint32_t        check;
+};
+
+static struct ao_boot __attribute__ ((section(".boot"))) ao_boot;
+       
+int
+ao_boot_check_chain(void)
+{
+       if (ao_boot.signal == AO_BOOT_SIGNAL && ao_boot.check == AO_BOOT_CHECK) {
+               ao_boot.signal = 0;
+               ao_boot.check = 0;
+               if (ao_boot.base == AO_BOOT_FORCE_LOADER)
+                       return 0;
+               ao_boot_chain(ao_boot.base);
+       }
+       return 1;
+}
+
+void
+ao_boot_reboot(uint32_t *base)
+{
+       ao_boot.base = base;
+       ao_boot.signal = AO_BOOT_SIGNAL;
+       ao_boot.check = AO_BOOT_CHECK;
+       ao_arch_reboot();
+}