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

5 files changed, 378 insertions, 0 deletions

diff --git a/rbutil/mkzenboot/dualboot/Makefile b/rbutil/mkzenboot/dualboot/Makefile
new file mode 100644
index 0000000000..cc8c604f6e
--- /dev/null
+++ b/rbutil/mkzenboot/dualboot/Makefile
@@ -0,0 +1,50 @@
+CC=gcc
+LD=ld
+OC=objcopy
+CROSS_PREFIX=arm-elf-eabi-
+REGS_PATH=../../../firmware/target/arm/imx233/regs
+CFLAGS=-mcpu=arm926ej-s -std=gnu99 -I. -I$(REGS_PATH) -nostdlib -ffreestanding -fomit-frame-pointer -O
+LDFLAGS=
+# Edit the following variables when adding a new target.
+# mkimxboot.c also needs to be edited to refer to these
+# To add a new target x you need to:
+# 1) add x to the list in TARGETS
+# 2) create a variable named OPT_x of the form:
+#    OPT_x=target specific defines
+TARGETS=zenmozaic zenxfi zen
+OPT_zenmozaic=-DCREATIVE_ZENMOZAIC -DIMX233_SUBTARGET=3700
+OPT_zenxfi=-DCREATIVE_ZENXFI -DIMX233_SUBTARGET=3700
+OPT_zen=-DCREATIVE_ZEN -DIMX233_SUBTARGET=3700
+
+BOOTLDS=$(patsubst %, dualboot_%.lds, $(TARGETS))
+BOOTOBJS=$(patsubst %, dualboot_%.o, $(TARGETS))
+BOOTBINS=$(patsubst %, dualboot_%.arm-bin, $(TARGETS))
+BOOTELFS=$(patsubst %, dualboot_%.arm-elf, $(TARGETS))
+
+all: ../dualboot.h ../dualboot.c $(BOOTELFS)
+
+# Dualboot bootloaders
+
+dualboot_%.o: dualboot.c
+	$(CROSS_PREFIX)$(CC) $(CFLAGS) $(OPT_$(@:dualboot_%.o=%)) -c -o $@ $^
+
+dualboot_%.lds: dualboot.lds
+	$(CROSS_PREFIX)$(CC) $(CFLAGS) $(OPT_$(@:dualboot_%.lds=%)) -E -x c - < $< | sed '/#/d' > $@
+
+dualboot_%.arm-elf: dualboot_%.o dualboot_%.lds
+	$(CROSS_PREFIX)$(LD) $(LDFLAGS) -T$(@:dualboot_%.arm-elf=dualboot_%.lds) -o $@ $<
+
+# Rules for the ARM code embedded in mkamsboot - assemble, link, then extract
+# the binary code and finally convert to .h for building in mkamsboot
+
+%.arm-bin: %.arm-elf
+	$(CROSS_PREFIX)$(OC) -O binary $< $@
+
+../dualboot.c ../dualboot.h: $(BOOTBINS) bin2c
+	./bin2c ../dualboot $(BOOTBINS)
+
+bin2c: bin2c.c
+	$(CC) -o bin2c bin2c.c
+
+clean:
+	rm -f *~ bin2c $(BOOTBINS) $(BOOTOBJS) $(BOOTELFS) $(BOOTLDS)
diff --git a/rbutil/mkzenboot/dualboot/bin2c.c b/rbutil/mkzenboot/dualboot/bin2c.c
new file mode 100644
index 0000000000..b02af88a4d
--- /dev/null
+++ b/rbutil/mkzenboot/dualboot/bin2c.c
@@ -0,0 +1,140 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2007 Dave Chapman
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <libgen.h>
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+static off_t filesize(int fd)
+{
+    struct stat buf;
+
+    fstat(fd,&buf);
+    return buf.st_size;
+}
+
+static void write_cfile(const unsigned char* buf, off_t len, FILE* fp, const char *name)
+{
+    int i;
+
+    fprintf(fp,"unsigned char %s[%ld] = {",name,len);
+
+    for (i=0;i<len;i++) {
+        if ((i % 16) == 0) {
+           fprintf(fp,"\n    ");
+        }
+        if (i == (len-1)) {
+            fprintf(fp,"0x%02x",buf[i]);
+        } else if ((i % 16) == 15) {
+            fprintf(fp,"0x%02x,",buf[i]);
+        } else {
+            fprintf(fp,"0x%02x, ",buf[i]);
+        }
+    }
+    fprintf(fp,"\n};\n");
+}
+
+int main (int argc, char* argv[])
+{
+    char* cname;
+    int i;
+    FILE *cfile, *hfile;
+    char cfilename[256], hfilename[256];
+
+    if (argc < 3) {
+        fprintf(stderr,"Usage: bin2c cname file1 [file2 [file3 ...]]\n");
+        return 1;
+    }
+
+    cname=argv[1];
+
+    snprintf(cfilename,256,"%s.c",cname);
+    cfile = fopen(cfilename,"w+");
+    if (cfile == NULL) {
+        fprintf(stderr,"Couldn't open %s\n",cfilename);
+        return 2;
+    }
+
+    snprintf(hfilename,256,"%s.h",cname);
+    hfile = fopen(hfilename,"w+");
+    if (hfile == NULL) {
+        fprintf(stderr,"Couldn't open %s\n",hfilename);
+        fclose(cfile);
+        return 3;
+    }
+
+    fprintf(cfile,"/* Generated by bin2c */\n\n");
+    fprintf(cfile,"#include \"%s\"\n\n", basename(hfilename));
+    fprintf(hfile,"/* Generated by bin2c */\n\n");
+
+    for(i=0; i < argc - 2; i++) {
+        unsigned char* buf;
+        off_t len;
+        off_t orig_len;
+        char *ext;
+        char *array = argv[2+i];
+
+        int fd = open(array,O_RDONLY|O_BINARY);
+        if (fd < 0) {
+            fprintf(stderr,"Can not open %s\n",argv[2+i]);
+            fclose(cfile);
+            fclose(hfile);
+            return 4;
+        }
+
+        orig_len = filesize(fd);
+        /* pad to 32bit */
+        len = (orig_len + 3) & ~3;
+
+        buf = malloc(len);
+        if (read(fd,buf,orig_len) < orig_len) {
+            fprintf(stderr,"Short read, aborting\n");
+            return 5;
+        }
+
+        /* pad to 32bit with zeros */
+        if (len > orig_len)
+            memset(buf+orig_len, 0, len-orig_len);
+        
+        /* remove file extension */
+        ext = strchr (array, '.');
+        if (ext != NULL)
+            *ext = '\0';
+        write_cfile (buf, len, cfile, array);
+        fprintf(hfile,"extern unsigned char %s[%ld];\n",array,len);
+
+        close(fd);
+    }
+
+    fclose(cfile);
+    fclose(hfile);
+
+    return 0;
+}
diff --git a/rbutil/mkzenboot/dualboot/config.h b/rbutil/mkzenboot/dualboot/config.h
new file mode 100644
index 0000000000..ff59cee710
--- /dev/null
+++ b/rbutil/mkzenboot/dualboot/config.h
@@ -0,0 +1,22 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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.
+ *
+ ****************************************************************************/
+
+/** empty, used by register files */
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);
+}
diff --git a/rbutil/mkzenboot/dualboot/dualboot.lds b/rbutil/mkzenboot/dualboot/dualboot.lds
new file mode 100644
index 0000000000..7444a1e427
--- /dev/null
+++ b/rbutil/mkzenboot/dualboot/dualboot.lds
@@ -0,0 +1,32 @@
+ENTRY(start)
+OUTPUT_FORMAT(elf32-littlearm)
+OUTPUT_ARCH(arm)
+
+MEMORY
+{
+    /* keep this consistent with the address in mkzenboot.c */
+#if IMX233_SUBTARGET == 3700
+    RAM : ORIGIN = 0x41000000, LENGTH = 0x8000
+#elif IMX233_SUBTARGET == 3600
+    RAM : ORIGIN = 0x61000000, LENGTH = 0x8000
+#else
+#error define me
+#endif
+}
+
+SECTIONS
+{
+    .text :
+    {
+        *(.start*)
+        *(.text*)
+        . = ALIGN(4);
+        LONG(0x1ceb00da)
+        of_vector = .;
+        . += 4;
+        rb_vector = .;
+        . += 4;
+        boot_arg = .;
+        . += 4;
+    } > RAM
+}