ARM/Thumb-2 kernel size comparison

The question of the size impact of building the kernel in Thumb-2 came up to day, so I extracted some quick numbers:

$ size vmlinux-* text data bss dec hex filename 8420507 463356 826928 9710791 942cc7 vmlinux-arm 6715539 463260 826928 8005727 7a285f vmlinux-thumb2

This is for a recent mainline kernel built with the linaro omap config.

In this case we save about 20% for code and read-only data (i.e., text) and 17.5% overall -- which accounts for a little under 2MB saved in this example.

This doesn't take loadable modules into accout; we can probably expect to see a similar size ratio there.

Cheers ---Dave