4 ms·

OpenWrt founder here; you've pretty much hit the nail on the head. Due to size constraints most platforms use a split filesystem consisting of a large read onl

by embeem 11y ago

OpenWrt founder here; you've pretty much hit the nail on the head. Due to size constraints most platforms use a split filesystem consisting of a large read only root filesystem and a smaller overlay for changes. The read only filesystem allows for much better compression ratios but it also means if you attempt to replace an individual package you'll end up with two copies, original in the RO and new in the overlay. Reflashing an OpenWrt device generally consists of migrating a minimal environment over to a ramdisk, rewriting the kernel and read only portions and then writing a backup of the config files to the overlay. On failure you're likely to be stuck in whatever rescue mode the bootloader provides.

kogepathic 11y ago
> Reflashing an OpenWrt device generally consists of migrating a minimal environment over to a ramdisk, rewriting the kernel and read only portions and then writing a backup of the config files to the overlay. Yup. Which is why auto updates will probably never work well. What if the user is running some custom software on the device and it doesn't have enough RAM to store the new compressed filesystem? These devices don't have swap. Routers are a subset of embedded systems, which means lots of different platforms, possibly with vendor included quirks, AND then users who run their own junk on them (ahem). Given that most manufacturers are loath to even release their uboot source (come on guys, it's a bootloader not missile launch codes) and most of the implementations I've seen are a ham fisted modification of an old revision of uboot; just enough to boot, but dragons exist in the code. Short of an iPhone for routers moment (yes,the irony of Apple's extremely closed system is not lost on me) where some company creates a router which just revolutionizes the whole industry[1], I don't see it happening on a consumer level unless there is a legislative requirement. [1] this won't happen because phones are fun and shiny and routers aren't. At least to your average consumer. Also the internet is awesome. An OpenWrt founder replied to my comment! :D

by embeem 11y ago

kogepathic 11y ago

> Reflashing an OpenWrt device generally consists of migrating a minimal environment over to a ramdisk, rewriting the kernel and read only portions and then writing a backup of the config files to the overlay. Yup. Which is why auto updates will probably never work well. What if the user is running some custom software on the device and it doesn't have enough RAM to store the new compressed filesystem? These devices don't have swap. Routers are a subset of embedded systems, which means lots of different platforms, possibly with vendor included quirks, AND then users who run their own junk on them (ahem). Given that most manufacturers are loath to even release their uboot source (come on guys, it's a bootloader not missile launch codes) and most of the implementations I've seen are a ham fisted modification of an old revision of uboot; just enough to boot, but dragons exist in the code. Short of an iPhone for routers moment (yes,the irony of Apple's extremely closed system is not lost on me) where some company creates a router which just revolutionizes the whole industry[1], I don't see it happening on a consumer level unless there is a legislative requirement. [1] this won't happen because phones are fun and shiny and routers aren't. At least to your average consumer. Also the internet is awesome. An OpenWrt founder replied to my comment! :D