zenxfi2: rework dualboot

The previous dualboot scheme had a major flow: it needed to hold
menu to boot OF but the X-Fi2 boot in recovery mode with menu!
It was possible but very trick to enter the OF with USB plugged.
This code provides a new scheme:
- no USB plugged: boot to OF when menu is pressed
- USB plugged: boot to OF when power is pressed

Change-Id: Ia6e76d3ada1f67137b727daa050cf6c77afbbfb9

3 files changed, 36 insertions, 5 deletions

diff --git a/rbutil/mkimxboot/dualboot.c b/rbutil/mkimxboot/dualboot.c
index 29e18eddf7..20876d77b0 100644
--- a/rbutil/mkimxboot/dualboot.c
+++ b/rbutil/mkimxboot/dualboot.c
@@ -14,10 +14,13 @@ unsigned char dualboot_fuzeplus[152] = {
     0x10, 0x86, 0x01, 0x80, 0xc0, 0x40, 0x04, 0x80, 0x70, 0x64, 0x08, 0x00, 0x80, 0x1a, 0x06, 0x00,
     0x00, 0x41, 0x04, 0x80, 0x01, 0x00, 0x77, 0x3e
 };
-unsigned char dualboot_zenxfi2[36] = {
-    0x18, 0x20, 0x9f, 0xe5, 0x00, 0x20, 0x92, 0xe5, 0x01, 0x09, 0x12, 0xe3, 0x00, 0x00, 0xa0, 0x03,
-    0x1e, 0xff, 0x2f, 0x01, 0x00, 0x00, 0x81, 0xe5, 0x01, 0x00, 0xa0, 0xe3, 0x1e, 0xff, 0x2f, 0xe1,
-    0x00, 0x86, 0x01, 0x80
+unsigned char dualboot_zenxfi2[92] = {
+    0x4c, 0x20, 0x9f, 0xe5, 0x00, 0x20, 0x92, 0xe5, 0x02, 0x21, 0xa0, 0xe1, 0x22, 0x2d, 0xa0, 0xe1,
+    0x20, 0x00, 0x12, 0xe3, 0x06, 0x00, 0x00, 0x0a, 0x34, 0x20, 0x9f, 0xe5, 0x00, 0x20, 0x92, 0xe5,
+    0x02, 0x25, 0xa0, 0xe1, 0x22, 0x2f, 0xa0, 0xe1, 0x01, 0x00, 0x52, 0xe3, 0x00, 0x00, 0xa0, 0x03,
+    0x03, 0x00, 0x00, 0xea, 0x1c, 0x20, 0x9f, 0xe5, 0x00, 0x20, 0x92, 0xe5, 0x01, 0x09, 0x12, 0xe3,
+    0x00, 0x00, 0xa0, 0x03, 0x1e, 0xff, 0x2f, 0x01, 0x00, 0x00, 0x81, 0xe5, 0x01, 0x00, 0xa0, 0xe3,
+    0x1e, 0xff, 0x2f, 0xe1, 0xc0, 0x40, 0x04, 0x80, 0x00, 0x86, 0x01, 0x80
 };
 unsigned char dualboot_zenxfi3[36] = {
     0x18, 0x20, 0x9f, 0xe5, 0x00, 0x20, 0x92, 0xe5, 0x80, 0x00, 0x12, 0xe3, 0x00, 0x00, 0xa0, 0x03,
diff --git a/rbutil/mkimxboot/dualboot.h b/rbutil/mkimxboot/dualboot.h
index 272e257996..eff50cc6c5 100644
--- a/rbutil/mkimxboot/dualboot.h
+++ b/rbutil/mkimxboot/dualboot.h
@@ -1,5 +1,5 @@
 /* Generated by bin2c */
 
 extern unsigned char dualboot_fuzeplus[152];
-extern unsigned char dualboot_zenxfi2[36];
+extern unsigned char dualboot_zenxfi2[92];
 extern unsigned char dualboot_zenxfi3[36];
diff --git a/rbutil/mkimxboot/dualboot/dualboot.S b/rbutil/mkimxboot/dualboot/dualboot.S
index ed91012199..0508f7e16a 100644
--- a/rbutil/mkimxboot/dualboot/dualboot.S
+++ b/rbutil/mkimxboot/dualboot/dualboot.S
@@ -66,11 +66,39 @@ power_down:
     str     r1, [r0]
     b       power_down
 #elif defined(CREATIVE_ZENXFI2)
+    /* We are lacking buttons on the Zen X-Fi2 because on USB, the select button
+     * enters recovery mode ! So we can only use power but power is used to power up
+     * on normal boots and then select is free ! Thus use a non-uniform scheme:
+     * - normal boot:
+     *   - no key: Rockbox
+     *   - select: OF
+     * - USB boot:
+     *   - no key: Rockbox
+     *   - power: OF
+     */
+    /* if the power source was 5v (ie usb), check for power (pswitch) */
+    ldr     r2, =0x800440c0 @ HW_POWER_STS
+    ldr     r2, [r2]
+    mov     r2, r2, lsl#2
+    mov     r2, r2, lsr#26 @ extract PWRUP_SOURCE
+    tst     r2, #0x20 @ bit 5: five volts
+    beq     boot_normal
+    /* check pswitch*/
+    ldr     r2, =0x800440c0 @ HW_POWER_STS
+    ldr     r2, [r2]
+    mov     r2, r2, lsl#10
+    mov     r2, r2, lsr#30 @ extract PSWITCH
+    cmp     r2, #1
+    moveq   r0, #0 @ 1 => boot OF
+    b       do_boot
+boot_normal:
     /* If select key is hold, return so that the OF can boot */
     ldr     r2, =0x80018600 @ HW_PINCTRL_DIN0
     ldr     r2, [r2]
     tst     r2, #0x4000 @ bit 14, active low
     moveq   r0, #0 @ return 0, continue boot
+    /* r0 must contain the 0 to boot OF and 1 to boot RB */
+do_boot:
     bxeq    lr
     str     r0, [r1]
     mov     r0, #1