iPod Classic: HW preliminary initialization for bootloader

When the bootloader starts, most of HW never has been initialized.
This patch includes all code needed to perform the preliminary
initialization on SYSCON, GPIO, i2c, and MIU.

The code is based on emCORE and OF reverse engineering, ported to
C for readability.

Change-Id: I9ecf2c3e8b1b636241a211dbba8735137accd05c

1 files changed, 19 insertions, 0 deletions

diff --git a/firmware/target/arm/s5l8702/gpio-s5l8702.c b/firmware/target/arm/s5l8702/gpio-s5l8702.c
index bd87005ad8..85033de78c 100644
--- a/firmware/target/arm/s5l8702/gpio-s5l8702.c
+++ b/firmware/target/arm/s5l8702/gpio-s5l8702.c
@@ -214,3 +214,22 @@ void ICODE_ATTR INT_EXT6(void)
     gpio_handler(0);
 }
 #endif
+
+#ifdef BOOTLOADER
+static uint32_t gpio_data[16] =
+{
+    0x5322222F, 0xEEEEEE00, 0x2332EEEE, 0x3333E222,
+    0x33333333, 0x33333333, 0x3F000E33, 0xEEEEEEEE,
+    0xEEEEEEEE, 0xEEEEEEEE, 0xE0EEEEEE, 0xEE00EE0E,
+    0xEEEE0EEE, 0xEEEEEEEE, 0xEE2222EE, 0xEEEE0EEE
+};
+
+void gpio_preinit(void)
+{
+    for (int i = 0; i < 16; i++) {
+        PCON(i) = gpio_data[i];
+        PUNB(i) = 0;
+        PUNC(i) = 0;
+    }
+}
+#endif