uboot-2021-rebase.git - uboot 2021 rebase, to fix booting on modern SD cards, from https://github.com/fifteenhex/u-boot/tree/am335x_som

Age	Commit message (Collapse)	Author
2018-05-07	SPDX: Convert all of our single license tags to Linux Kernel style	Tom Rini
	When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
2014-11-21	x86: ivybridge: Implement SDRAM init	Simon Glass
	Implement SDRAM init using the Memory Reference Code (mrc.bin) provided in the board directory and the SDRAM SPD information in the device tree. This also needs the Intel Management Engine (me.bin) to work. Binary blobs everywhere: so far we have MRC, ME and microcode. SDRAM init works by setting up various parameters and calling the MRC. This in turn does some sort of magic to work out how much memory there is and the timing parameters to use. It also sets up the DRAM controllers. When the MRC returns, we use the information it provides to map out the available memory in U-Boot. U-Boot normally moves itself to the top of RAM. On x86 the RAM is not generally contiguous, and anyway some RAM may be above 4GB which doesn't work in 32-bit mode. So we relocate to the top of the largest block of RAM we can find below 4GB. Memory above 4GB is accessible with special functions (see physmem). It would be possible to build U-Boot in 64-bit mode but this wouldn't necessarily provide any more memory, since the largest block is often below 4GB. Anyway U-Boot doesn't need huge amounts of memory - even a very large ramdisk seldom exceeds 100-200MB. U-Boot has support for booting 64-bit kernels directly so this does not pose a limitation in that area. Also there are probably parts of U-Boot that will not work correctly in 64-bit mode. The MRC is one. There is some work remaining in this area. Since memory init is very slow (over 500ms) it is possible to save the parameters in SPI flash to speed it up next time. Suspend/resume support is not fully implemented, or at least it is not efficient. With this patch, link boots to a prompt. Signed-off-by: Simon Glass <sjg@chromium.org>