mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-19 21:58:04 +00:00
dc451a4b24
The flash layout on the Storlink reference design for Gemini is using 2 MB flash for the kernel, and it also insists on overwriting the partition table with default values on every boot. The same is true for the SQ201. This poses a problem on recent OpenWrt firmware as the base zImage is bigger than 2 MB. At the same time there is a ramdisk partition of 6 MB that we don't really need. The partition table looks like this: Creating 7 MTD partitions on "30000000.flash": 0x000000000000-0x000000016000 : "BOOT" 0x000000120000-0x000000320000 : "Kern" 0x000000320000-0x000000920000 : "Ramdisk" 0x000000920000-0x000000f20000 : "Application" 0x000000f20000-0x000000f40000 : "VCTL" 0x000000f40000-0x000000fe0000 : "CurConf" 0x000000fe0000-0x000001000000 : "FIS directory" On boot the "Kern" partition is copied to RAM @0x01600000 and the "Ramdisk" partition is copied to RAM @0x00800000. Then the kernel is executed. The idea with this patch is to extend the "Kern" partition with the "Ramdisk" partition to get a full 8 MB to use for the kernel. Then we put the OpenWrt JFFS2 rootfs inside the "Application" partition. We create a small assembly loop that we prepend to the "Kern" image that will copy the "Kern" from 0x0160000 and the "Ramdisk" from 0x00800000 and put them in consecutive space at 0x00400000 and execute it from there, using "Application" as rootfs. We generate 3 main files: - zImage - contains the assembly bootstrap loop and the first part of the generated kernel image - rd.gz - contains the second part of the generated kernel image - hddapp.tgz - contains the root filesystem On the SQ201 I flash these manually using the native boot loader PLATO, "Y" alternative for the zImage, "R" for the rd.gz image and "A" for hddapp.tgz. This works fine and I can now boot to prompt on the SQ201 with nothing but flash. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> |
||
|---|---|---|
| .. | ||
| base-files | ||
| image | ||
| patches-4.14 | ||
| patches-4.19 | ||
| config-4.14 | ||
| config-4.19 | ||
| Makefile | ||