Hi Simon,
On Tue, 8 Oct 2019 at 14:34, Simon Goldschmidt simon.k.r.goldschmidt@gmail.com wrote:
In a series I'm currently preparing, I've stumbled accross the fact that IS_ERR_VALUE() doesn't reliably work on socfpga SPL as the onchip SRAM begins at 0xffff0000 and the heap is at the end of the 32 bit range.
Which function is returning that address?
Being like that, the current test for error (value >= -4095) which equals 'value >= 0xfffff001' would require us to waste the last 4K of that memory, which is not an option when it comes to using DM in SPL...
Now on this platform, I'm sure I could find a range of 4096 bytes to use as invalid pointer range, but the question is: how do I integrate that into U-Boot in a clean manner? Would it be acceptable to change the error headers imported from Linux or would I have to through the hassle of changing Linux first?
Or does anyone have a better idea to allow using the last 4K for heap?
Regards, Simon