From 5d6e4981788c7e9a2fdd710d598cd10cb8f6b6dc Mon Sep 17 00:00:00 2001 From: Solomon Peachy Date: Sat, 21 Sep 2024 11:00:53 -0400 Subject: manual: Document storage/capacity limits and "SSD Mods" Change-Id: Ida3e4bc2129bfa3481ddcc961f4156c3033189a1 --- manual/getting_started/installation.tex | 57 +++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) (limited to 'manual') diff --git a/manual/getting_started/installation.tex b/manual/getting_started/installation.tex index b59a4e1f38..633f8ac4ad 100644 --- a/manual/getting_started/installation.tex +++ b/manual/getting_started/installation.tex @@ -268,6 +268,63 @@ of before installing. \end{description} } +\subsection{Storage/Capacity Limits} + +\note{As of this writing, no Rockbox-capable device can handle + total drive capacities exceeding than 2TiB.} + +\opt{disk_storage}{ +Rockbox supports larger drive capacities when used on devices +that use ATA storage and GPT partitioning, but due to the limitations +of the FAT32 filesystem, individual paritions cannot exceed 2TiB. Additionally, +there are typically underlying platform limitations that +make it difficult, if not impossible, to boot from a GPT-partitioned +drive. +} + +\opt{sd_storage}{ + \note{SD cards exceeding 32GiB are pre-formated using the exFAT filesystem with GPT paritioning. + Before they can be used with Rockbox, they must be reformatted with FAT32.} + + Rockbox does not currently support SDUC cards with capacities exceeding 2TiB. However, this is purely + a software limitation with Rockbox's SD card drivers, and will be addressed in a future release. +} + +\opt{disk_storage}{ +\subsection{Flash/SSD mods} + It is common to replace the device's original mechanical hard drive with + some sort of solid-state storage. Older versions of Rockbox (3.15 or prior) do not work properly with many + of these so-called ``flash mods'', the most common symptom being data corruption on write operations. All + known data integrity issues have been resolved, but each type of adapter has its own quirks: +\begin{description} +\item[Compact Flash.] True Compact Flash cards \emph{natively} implement the ATA command set, including + advanced power management and the \emph{removeable} attribute. They are performant, reliable, and physically + robust, but tend to be expensive and not available in larger sizes. +\item[SATA.] These are fast, reliable, and available in high capacities, but are typically optimized for high performance + at the expense of power consumption.. However, as they implement the full ATA command set, we are able + to aggressively power them down when not being actively used. +\item[Single Secure Digital (SD).] While these adapters come in different form factors from multiple vendors, + they are all based on the same basic design. The ATA command set is \emph{incompletely emulated}, notably lacking + support for the \emph{mandatory} ATA power management commands that Rockbox uses to flush caches and safely + transition the device in and out of low power states. Additionally, SD cards themselves vary widely in quality + and power consumption, leading to widely varying battery life. Finally, they do not support SDUC cards at all so are + limited to individual cards of 2TiB or less. +\item[Dual/Quad SD.] These are similar to the above, only allowing use of mulitiple SD cards to + increase the overall storage capacity. While typically described as JBOD\footnote{Just a Bunch Of Disks}, this is not accurate as each + card is not individually accessable. Instead, the adapter claims to be to be a single logical drive + that is the combined capacity of the individual cards in a RAID0-like manner. This also means that if any + one card fails, you lose everything. Combined with the poor quality of most SD cards and the lack of support + for proper power management, this means use of multiple SD cards in one of these adapters is the reliable and most + power hungry solution of all. Finally, in another violation of the ATA specification, these ATA<->SD adapters fail + to support addresses exceeding 32 bits, meaning that no matter which combination of cards is used, they simply will + not work if their combined capacity exceeds 2TiB. +\item + All of these flash/SSD mods take up less physical space in the device enclosure than the original hard drive, so care + must be taken to ensure they are securely mounted and resistant to the vibration and impacts that typically occur + in portable devices. Ribbon cables are particularly vulnerable. +\end{description} +} + \section{Installing Rockbox}\label{sec:installing_rockbox}\index{Installation} There are two ways to install Rockbox: automated and manual. The automated way is the preferred method of installing Rockbox for the majority of -- cgit v1.2.3