From 2e0c558064ad6c92624a0a826721a83321b227af Mon Sep 17 00:00:00 2001
From: Amaury Pouly <amaury.pouly@gmail.com>
Date: Tue, 22 Oct 2013 00:48:33 +0200
Subject: Introduce rbutil/mkzenboot, a replacement for tools/mkzenboot

The old tools/mkzenboot has a number of problems: very hard to maintain,
poor integration with rbutil. Restart from scratch by recycling all the
crypto and descrambling code, rewrite the actual firmware modification part
to handle all scenarios in a much clearer way. The code is ready to be
integrated into Rockbox Utility, by using the very similar interface to
mkimxboot.
I copied all the keys from the old mkzenboot, so it can potentially support
the older Creative ports, but since this is untested, I prefer not do so
at the moment. However, I did add a "mixed" boot option to support the
dualboot style used in the older ports.

Change-Id: I80cfc48fa78187baa1b1692e8a30ec7137cea37b
---
 rbutil/mkzenboot/dualboot/dualboot.c | 134 +++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 rbutil/mkzenboot/dualboot/dualboot.c

(limited to 'rbutil/mkzenboot/dualboot/dualboot.c')

diff --git a/rbutil/mkzenboot/dualboot/dualboot.c b/rbutil/mkzenboot/dualboot/dualboot.c
new file mode 100644
index 0000000000..d0587fa65d
--- /dev/null
+++ b/rbutil/mkzenboot/dualboot/dualboot.c
@@ -0,0 +1,134 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2013 by Amaury Pouly
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "regs-pinctrl.h"
+#include "regs-power.h"
+#include "regs-lradc.h"
+
+typedef unsigned long uint32_t;
+
+// target specific boot decision
+enum boot_t
+{
+    BOOT_STOP,  /* power down */
+    BOOT_ROCK, /* boot to Rockbox */
+    BOOT_OF, /* boot to OF */
+};
+
+/**
+ * Helper functions
+ */
+
+static inline int __attribute__((always_inline)) read_gpio(int bank, int pin)
+{
+    return (HW_PINCTRL_DINn(bank) >> pin) & 1;
+}
+
+static inline int __attribute__((always_inline)) read_pswitch(void)
+{
+#if IMX233_SUBTARGET >= 3700
+    return BF_RD(POWER_STS, PSWITCH);
+#else
+    return BF_RD(DIGCTL_STATUS, PSWITCH);
+#endif
+}
+
+/* only works for channels <=7, always divide by 2, never accumulates */
+static inline void __attribute__((always_inline)) setup_lradc(int src)
+{
+    BF_CLR(LRADC_CTRL0, SFTRST);
+    BF_CLR(LRADC_CTRL0, CLKGATE);
+    /* don't bother changing the source, we are early enough at boot so that
+     * channel x is mapped to source x */
+    HW_LRADC_CHn_CLR(src) = BM_OR2(LRADC_CHn, NUM_SAMPLES, ACCUMULATE);
+    BF_SETV(LRADC_CTRL2, DIVIDE_BY_TWO, 1 << src);
+}
+
+#define BP_LRADC_CTRL1_LRADCx_IRQ(x)    (x)
+#define BM_LRADC_CTRL1_LRADCx_IRQ(x)    (1 << (x))
+
+static inline int __attribute__((always_inline)) read_lradc(int src)
+{
+    BF_CLR(LRADC_CTRL1, LRADCx_IRQ(src));
+    BF_SETV(LRADC_CTRL0, SCHEDULE, 1 << src);
+    while(!BF_RD(LRADC_CTRL1, LRADCx_IRQ(src)));
+    return BF_RDn(LRADC_CHn, src, VALUE);
+}
+
+static inline void __attribute__((noreturn)) power_down()
+{
+    /* power down */
+    HW_POWER_RESET = BM_OR2(POWER_RESET, UNLOCK, PWD);
+    while(1);
+}
+
+/**
+ * Boot decision functions
+ */
+
+#if defined(CREATIVE_ZENMOZAIC) || defined(CREATIVE_ZEN) || defined(CREATIVE_ZENXFI)
+static enum boot_t boot_decision()
+{
+    setup_lradc(0); // setup LRADC channel 0 to read keys
+    /* make a decision */
+    /* read keys */
+    int val = read_lradc(0);
+    /* if back is pressed, boot to OF
+     * otherwise boot to RB */
+    if(val >= 2650 && val < 2750) // conveniently, all players use the same value
+        return BOOT_OF;
+    return BOOT_ROCK;
+}
+#else
+#warning You should define a target specific boot decision function
+static int boot_decision()
+{
+    return BOOT_ROCK;
+}
+#endif
+
+static int main(uint32_t rb_addr, uint32_t of_addr)
+{
+    switch(boot_decision())
+    {
+        case BOOT_ROCK:
+            return rb_addr;
+        case BOOT_OF:
+            /* fix back the loading address
+            /* NOTE: see mkzenboot for more details */
+            *(uint32_t *)0x20 = of_addr;
+            return 0;
+        case BOOT_STOP:
+        default:
+            power_down();
+    }
+}
+
+/** Glue for the linker mostly */
+
+extern uint32_t of_vector;
+extern uint32_t rb_vector;
+extern uint32_t boot_arg;
+
+void __attribute__((section(".start"))) start()
+{
+    uint32_t addr = main(rb_vector, of_vector);
+    ((void (*)(uint32_t))addr)(boot_arg);
+}
-- 
cgit v1.2.3