On Wed, Jul 24, 2024 at 09:08:47AM -0600, Simon Glass wrote:
The global data structure has grown quite a lot over the years, being the best place to put an important pointer or something that must be accessed before and after relocation.
This series attempts to reduce the size a little, by moving some things out and shrinking and aligning some fields.
Some fields are needed during init but not afterwards. To deal with this a new 'boardf' structure is created, which sits on the stack and is only present during board_init_f(). It is possible that more fields could move to this struct, but for now only 4 are moved.
An assumption is made that an int is 32-bits wide on all architectures, which seems to be true, but maintainers should be able to confirm.
Mostly the code-size impact is neutral, but the patch 'Use less space for environment fields' does increase U-Boot's size by about 30 bytes on aarch64.
For firefly-rk3399 (64-bit) the size of global reduces from 456 to 368 bytes. For SPL it reduces from 416 to 272 bytes.
There are other things which could be attempted, for example:
- Using hlist instead of list for some lists
- Checking that only necessary fields are present in SPL
This is good, thanks for doing this. I'm planning to grab this in to -next once I open it.