u-boot.git, branch v2021.07-rc3

Prepare v2021.07-rc3

2021-05-25T00:53:13Z

Signed-off-by: Tom Rini

Merge branch '2021-05-24-add-lto-support'

2021-05-24T20:12:31Z

- Add LTO (link time optimization) support to the build system and enable it on a few boards. This is an alternative to using -ffunction-sections/-fdata-sections and --gc-sections at link time to remove unused code. This can result in notable savings, but needs testing on each platform before use as it can expose problems by optimizing away various functionally necessary calls.

stackprot: Make our test a bit more complex

2021-05-24T18:23:01Z

With better compiler optimizations available, a compiler may see we do nothing with our buffer after calling memset and omit the call, thus causing us to not smash the stack. Add a comment to explain why we now also have a printf call, so that the test will pass as the memset will not be omitted. Reported-by: Marek Behún Signed-off-by: Tom Rini

ARM: enable LTO for some boards

2021-05-24T18:21:30Z

Enable LTO for some boards that were tested by people on U-Boot Mailing List. Signed-off-by: Marek Behún Tested-by: Adam Ford Tested-by: Pali Rohár Tested-by: Tim Harvey

ARM: don't use --gc-sections with LTO when using private libgcc

2021-05-24T18:21:30Z

When using LTO, we can throw away the --gc-sections flag, but only if using private libgcc. When using system's libgcc, --gc-sections is still needed, otherwise linking will fail due to undefined references to libc's symbols. Signed-off-by: Marek Behún Reviewed-by: Simon Glass

ARM: don't use -ffunction-sections/-fdata-sections with LTO build

2021-05-24T18:21:30Z

When building with LTO, using -ffunction-sections/-fdata-sections is not useful anymore. Signed-off-by: Marek Behún Reviewed-by: Simon Glass

ARM: make LTO available

2021-05-24T18:21:30Z

Make LTO available for ARM architecture. Signed-off-by: Marek Behún Reviewed-by: Simon Glass

ata: ahci: fix ahci_link_up() type mismatch for LTO

2021-05-24T18:21:30Z

When building highbank_defconfig with LTO, the compiler complains about type mismatch of function ahci_link_up(). The third parameter of this function is of type u8 in drivers/ata/ahci.c, but of type int in board/highbank/ahci.c. There is no reason in using u8, and the code using this function actually passes an int variable into the function (so it is implicitly converted to u8). Change the type of this parameter to int in drivers/ata/ahci.c. Signed-off-by: Marek Behún Reviewed-by: Bin Meng

armv8: SPL: discard relocation information

2021-05-24T18:21:30Z

For some reason when building SPL for ARMv8 with LTO, the relocation information is not discarded. Discard it explicitly in the linker script. This fixes LTO build for imx8mm_venice_defconfig. Signed-off-by: Marek Behún Reviewed-by: Simon Glass

ARM: omap3: fix LTO for DM3730 (and possibly other omap3 boards)

2021-05-24T18:21:30Z

Adam Ford says that DM3730 needs board.c compiled without LTO flags. Signed-off-by: Marek Behún Tested-by: Adam Ford