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| zh:supported_devices:432_warning [2020/01/08 13:51] – [扩展性] lujimmy | zh:supported_devices:432_warning [2020/01/08 14:31] – [可用性问题] lujimmy | ||
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| {{section> | {{section> | ||
| - | ===== 可用性问题 | + | ===== 可用性 ===== |
| **内存不足影响运行稳定** | **内存不足影响运行稳定** | ||
| Line 35: | Line 35: | ||
| ===== 支持性 ===== | ===== 支持性 ===== | ||
| - | 随着时间的发展,小内存和闪存设备将会越来越难得到支持。OpenWRT可能会在近期停止这些设备的支持。 | + | 随着时间的发展,小内存和闪存设备将会越来越难得到支持。OpenWrt近期可能会在无照会的情况下结束对这些设备的支持。 |
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| maximum usable firmware size: 3538944 bytes</ | maximum usable firmware size: 3538944 bytes</ | ||
| (以上数字是包括luci和大致相同的功能集的各发行版本镜像大小) | (以上数字是包括luci和大致相同的功能集的各发行版本镜像大小) | ||
| + | |||
| + | ===== Supportability issues ===== | ||
| + | |||
| + | It is getting harder or even impossible over time to support devices with low Flash + RAM. | ||
| + | OpenWrt support for those devices will likely end without warning at any time in the near future. | ||
| + | |||
| + | |||
| + | ===== Advice ===== | ||
| + | |||
| + | Users that are not expert users of OpenWrt (those that can build their own images) should consider | ||
| + | |||
| + | **16/64 as an // | ||
| + | |||
| + | Users should expect that devices with less than 16 MB of flash and/or 64 MB of RAM may be unstable in basic operation under current versions of OpenWrt (17.X, 18.X). They should further expect that support for the device may be dropped at any time and that security patches/ | ||
| + | |||
| + | Previous versions of OpenWrt (such as earlier versions of 17.X, 15.X, "Chaos Calmer" | ||
| + | |||
| + | ===== An analysis of the issue done by forum user slh ===== | ||
| + | As written in [[https:// | ||
| + | |||
| + | First of all, I'm not pretending to speak for the LEDE team, however looking at the plain numbers presents a quite obvious situation. | ||
| + | |||
| + | Taking " | ||
| + | |||
| + | < | ||
| + | Backfire 10.03..............: | ||
| + | Backfire 10.03.1............: | ||
| + | Attitude Adjustment 12.09...: 2883588 bytes | ||
| + | Barrier Breaker 14.07.......: | ||
| + | Chaos Calmer 15.05..........: | ||
| + | Chaos Calmer 15.05.1........: | ||
| + | LEDE 17.01 release branch...: 3473412 bytes | ||
| + | absolute firmware size......: 3735576 bytes | ||
| + | maximum usable firmware size: 3538944 bytes</ | ||
| + | (all of these figures are for release images, including luci and a more or less identical feature set). | ||
| The erase block size for this (and most other) devices is 64 KB, so you now end up with 256 KB (== 4 erase blocks) free space, compared to 320 KB (== 5 erase blocks before). While this may look comfortable at a first glance, you have to consider that free space can only be assigned in (full) block size chunks, so once you touch the overlay partition at all, you already have one erase block in use (64 KB). Therefore the firmware creation tools used by LEDE enforce at least 3 erase blocks reserve for the overlay filesystem (that' | The erase block size for this (and most other) devices is 64 KB, so you now end up with 256 KB (== 4 erase blocks) free space, compared to 320 KB (== 5 erase blocks before). While this may look comfortable at a first glance, you have to consider that free space can only be assigned in (full) block size chunks, so once you touch the overlay partition at all, you already have one erase block in use (64 KB). Therefore the firmware creation tools used by LEDE enforce at least 3 erase blocks reserve for the overlay filesystem (that' | ||
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| [4] I would expect that there already are a couple of 4 MB flash devices in the target list for which no release firmware can be built for 17.01, because of less ideal flash partitioning schemes chosen by the vendor (dropping free space below 3 erase blocks). Those are probably a minority, but given the close numbers, I'd be very suprised if there wouldn' | [4] I would expect that there already are a couple of 4 MB flash devices in the target list for which no release firmware can be built for 17.01, because of less ideal flash partitioning schemes chosen by the vendor (dropping free space below 3 erase blocks). Those are probably a minority, but given the close numbers, I'd be very suprised if there wouldn' | ||
| - | [[https:// | + | [[https:// |
| ===== The opinion of a Core LEDE developer ===== | ===== The opinion of a Core LEDE developer ===== | ||
| - | As originally written in [[https:// | + | As originally written in [[https:// |
| Just providing my rather pragmatic opinion on the topic here:\\ | Just providing my rather pragmatic opinion on the topic here:\\ | ||