On 26.05.20 13:25, Marek Vasut wrote:
On 5/26/20 1:12 PM, Soeren Moch wrote:
On 25.05.20 22:24, Anatolij Gustschin wrote:
Converting to DM increases binary size and breaks building some boards (i.e. tbs2910, gcc 9.2). The approach to address this issue via cutting off unused properties/nodes in device tree via custom u-boot.dtsi was not welcome, even if the affected boards do not pass the built-in device tree to the kernel.
But there is CONFIG_OF_REMOVE_PROPS="dmas dma-names interrupt-parent interrupts interrupts-extended interrupt-names interrupt-map interrupt-map-mask" in tbs2910_defconfig. So removing properties is already done via this config option. Removing nodes is not implemented (yet? AFAIK). But would be welcome if someone implements this in a similar way, I think.
Why don't we turn this the other way around -- put the { compat string , driver } tuple list into a U-Boot linker list, then filter this linker list against a DT which will be used for the platform (what if there are multiple DTs?), and then scrub all unreferrenced symbols.
I think we discussed this idea earlier, and indeed this sounds more promising. Apparently it is more difficult to implement, so this CONFIG_OF_REMOVE_PROPS was done as first step. Unfortunately I'm not familiar with fdt transformations, nor linker scripts. So I cannot really judge the required effort. But I would be happy if someone else implements this.
Soeren