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Rockbox General => Rockbox General Discussion => Topic started by: GCRaistlin on August 07, 2021, 07:24:34 AM

Title: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: GCRaistlin on August 07, 2021, 07:24:34 AM
In the manual, USB Mode setting is mentioned. Although I don't see it in my Settings - General Settings - System menu: the last item there is USB Keypad Mode. Is it expected?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: braewoods on August 07, 2021, 08:07:57 AM
Is it the latest stable or development release? I think that was added only recently.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: gswallow on December 18, 2021, 11:45:00 AM
Found an 80GB iPod Video at a local GoodWill and -- to my surprise it worked. Needed a new Head Jack & Hold cable. So, long story short, upgraded with a iFlash PCB with a 1TB SSD and a 3AH battery. Works great tested in my Edge and could control from the steering wheel. My music collection is larger than SYNC can handle.

Needed to organize better than 50k MP3 files so got Rockbox Utility. I have macOS 10.15.7 and XP here and could only get the RB 1.4.0 to install from XP. macOS said wrong CPU. Did and install and dropped a mSSD patch (beyondwind maybe) onto the install root and am up and running. But, just as this user am curious to the missing USB Mode option. I figure this is what I need to change as Rockbox goes to the USB Keypad mode et al and I can get no play back.

Any work around? I wonder about manually updating as dropping the latest build into my install might dump the patch for SSD?


Thanks in advance

GregS <><
Rockbox RBU 1.4.0, RB d4d233c31aM-201028 (patched)
iPod Video 5G (iFlash-1TB-SSD, 3AH battery)
MBP i7 (16GB, 1TB SSD, macOS 10.15.7)
P4 (2gb, XP SP3)
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: GCRaistlin on December 18, 2021, 11:57:11 AM
Install the latest dev build, it has this feature implemented, as well as a lot of USB issues fixed.  But ATM this very feature may still not work properly.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: gswallow on December 20, 2021, 09:04:18 AM
Dropped the latest Dev Build onto iPod and got USB Mode. That does what it is supposed to do. Problem is evidently my car: 2011 Ford Edge Limited (Sync 2 v3). It sees the iPod as an "Unsupported Device" when booted into Rockbox. Have found a couple of try this YouTubes, but nothing worked so far. Next will be: drop one song onto iPod via Itunes/Music and connect to Ford and play. Then reboot Rockbox. The theory is that the Sync sees Rockbox after it has talked to the iPod. I have my doubts. but I need the space that Rockbox gives for my music collection. Booting the iPOd as a drive would be no better than the 2TB drive I have now.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: GCRaistlin on December 20, 2021, 09:12:13 AM
Perhaps iPod doesn't support more than 2TB in any mode (FAT32 limitation). Though I haven't checked it myself.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: amachronic on December 20, 2021, 10:42:03 AM
GCRaistlin is correct: Rockbox can't support drives bigger than 2 TB.

Make sure you set USB Mode -> Mass Storage and USB HID -> Off. It's the USB HID setting which enables & disables the keypad mode, which might confuse the car. The USB Mode setting allows you to control whether Rockbox goes into mass storage mode or charging only. If you set USB Mode to Ask it's supposed to prompt you, so you can choose which mode to enter each time you plug in, but that option is currently broken on many players -- including iPods -- so you shouldn't use it.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: saratoga on December 20, 2021, 12:02:50 PM
What is the limit at 2TB?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: amachronic on December 20, 2021, 12:54:23 PM
Well, the main limiting factor is the use of 32-bit addressing & 512-byte sectors everywhere (the FAT driver, storage API, etc). MBR can't support >2 TiB partitions, though supporting GPT wouldn't be much of a stretch. Whether Apple firmware / other OFs would accept that is another story. I believe FAT32 can be cajoled up to 16 TiB, but ideally you'd want exFAT at those sizes.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: saratoga on December 20, 2021, 02:46:57 PM
Ah right. But you could still do two partitions of 2 TB I think?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: amachronic on December 20, 2021, 04:00:42 PM
Unfortunately not. Rockbox can't address a drive beyond the 2 TB mark at all. We'd need to switch to 64-bit addressing throughout the storage stack to break that limit.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: philden on December 20, 2021, 04:56:15 PM
A Ebay seller called tipakay sells 4TB iPods and claims they work with Rockbox. I contacted him and asked if he really sold any 4TB models and he claims he does and that they work, but wouldn't reveal how he does it.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: amachronic on December 21, 2021, 08:43:24 AM
I guess at least the iPod ports must have a way around this then, or he is providing an 'unofficial' build?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: bluebrother on December 21, 2021, 10:45:28 AM
I guess at least the iPod ports must have a way around this then, or he is providing an 'unofficial' build?

Hmm -- addressing with 32 bit gives me 2^32 = 4Ti, so addressing 4TiB should work. Since FAT32 has 2TiB limit two partitions could actually work, so that might be the trick. Or where's the mistake in my calculation?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: GCRaistlin on December 21, 2021, 10:50:20 AM
Then why doesn't MBR support drives over 2.2 TB?
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: Bilgus on December 21, 2021, 09:26:18 PM
Problem is evidently my car: 2011 Ford Edge Limited (Sync 2 v3). It sees the iPod as an "Unsupported Device" when booted into Rockbox.


DO NOTE

Rockbox will not work with a car as an ipod would

a rockboxed ipod can only be used as a (usb) drive in mass storage mode or as line in to your stereo

Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: speachy on December 22, 2021, 10:52:11 PM
MBR's sector addresses are 32-bits.  This means there can only be 2^32 (=~ 4 billion) addressable sectors.  With the hardware using 512 byte sectors, this yields both a maximum disk and partition size of 2^32 * 512 == 2 terabytes.

In theory with a drive that uses >612B sectors would support larger disk sizes under MBR, but crucially SD cards, even the latest SDUC, still use 512 byte blocks.

As already mentioned, In order to utilize more than 2TB on a single physical drive (note the quad iflash adapter counts as a "single" drive in this context), Rockbox would need support for GPT partitions (not that difficult) but critically also would need to move to 64-bit addressing throughout the storage stack.  But even once that's in place, FAT32 is still limited to 32-bit sector counts, yielding the same 2TB partition size limit on 512-byte sector drives.

ExFAT blows away those limits, but would be a significant undertaking to implement.
Title: Re: [iPod 5.5G 30GB] USB Mode is missing from the Settings menu
Post by: bluebrother on December 23, 2021, 03:51:09 AM
MBR's sector addresses are 32-bits.  This means there can only be 2^32 (=~ 4 billion) addressable sectors.  With the hardware using 512 byte sectors, this yields both a maximum disk and partition size of 2^32 * 512 == 2 terabytes.

Ah, forgot about the sector size. Stupid me :-[