u-boot.git/arch/arm/include/asm/spl.h, branch v2022.07

spl: Add semihosting boot method

2022-04-01T19:03:13Z

This adds a boot method for loading the next stage from the host. It is mostly modeled off of spl_load_image_ext. I am not really sure why/how spl_load_image_fat uses three different methods to load the image, but the simple case seems to work OK for now. To control the presence of this boot method, we add a config symbol. While we're at it, we update the original semihosting config symbol. I think semihosting has some advantages of other forms of JTAG boot. Common other ways to boot from JTAG include: - Implementing DDR initialization through JTAG (typically with dozens of lines of TCL) and then loading U-Boot. The DDR initialization typically uses hard-coded register writes, and is not easily adapted to different boards. BOOT_DEVICE_SMH allows booting with SPL, leveraging U-Boot's existing DDR initialization code. This is the method used by NXP's CodeWarrior IDE on Layerscape processors (see AN12270). - Loading a bootloader into SDRAM, waiting for it to initialize DDR, and then loading U-Boot. This is tricky, because the debugger must stop the boot after the bootloader has completed its work. Trying to load U-Boot too early can cause failure to boot. This is the method used by Xilinx with its Zynq(MP) processors. - Loading SPL with BOOT_DEVICE_RAM and breaking before SPL loads the image to load U-Boot at the appropriate place. This can be a bit tricky, because the load address is dependent on the header size. An elf with symbols must also be used in order to stop at the appropriate point. BOOT_DEVICE_SMH can be viewed as an extension of this process, where SPL automatically stops and tells the host where to place the image. Signed-off-by: Sean Anderson

arm: K3: am654: Add support for boot device detection

2018-09-11T12:32:55Z

AM654 allows for booting from primary or backup boot media. Both media can be chosen individually based on switch settings. ROM looks for a valid image in primary boot media, if not found then looks in backup boot media. In order to pass this boot media information to boot loader, ROM stores a value at a particular address. Add support for reading this information and determining the boot media correctly. Signed-off-by: Lokesh Vutla Signed-off-by: Andreas Dannenberg Signed-off-by: Vignesh R Reviewed-by: Tom Rini

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12Z

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

spl: add a 'return to bootrom' boot method

2017-08-13T15:12:19Z

Some devices (e.g. the RK3368) have only limited SRAM, but provide support for loading the next boot stage after our SPL performs basic setup (e.g. DRAM). For target systems like these, we add a boot device BOOTROM that will invoke a board-specific hook to return to the bootrom (if supported). Signed-off-by: Philipp Tomsich Reviewed-by: Tom Rini Reviewed-by: Simon Glass

SPL: Add XIP booting support

2017-06-09T15:23:59Z

Enable support for XIP (execute in place) of U-Boot or kernel image. There is no need to copy image from flash to ram if flash supports execute in place. Signed-off-by: Vikas Manocha Reviewed-by: Alexandru Gagniuc

TI: Drop 'CONFIG_OMAP'

2017-05-15T14:39:56Z

In the two cases in the code where we use CONFIG_OMAP as a useful test currently we can make use of CONFIG_ARCH_OMAP2PLUS instead. With that changed we can drop all defines of CONFIG_OMAP. While in here, CONFIG_OMAP3430 is only defined and then never used, so drop. Signed-off-by: Tom Rini

spl: Move spl_board_load_image() into a generic header

2016-10-06T18:48:14Z

At present this is only used on ARM and sandbox, but it is just as applicable to other architectures. Move the function prototype into the generic SPL header. Signed-off-by: Simon Glass Reviewed-by: Tom Rini

ARM: Add new BOOT_DEVICE_DFU boot mode

2016-09-22T05:33:20Z

This enum is needed when SPL_DFU is enabled. Signed-off-by: Michal Simek

spl: define BOOT_DEVICE_USB

2016-02-14T07:36:13Z

This enum is referenced from common/spl/spl.c. Signed-off-by: Masahiro Yamada

spl: change return values of spl_*_load_image()

2015-11-18T19:50:02Z

Make spl_*_load_image() functions return a value instead of hanging if a problem is encountered. This enables main spl code to make the decision whether to hang or not, thus preparing it to support alternative boot devices. Some boot devices (namely nand and spi) do not hang on error. Instead, they return normally and SPL proceeds to boot the contents of the load address. This is considered a bug and is rectified by hanging on error for these devices as well. Signed-off-by: Nikita Kiryanov Cc: Igor Grinberg Cc: Tom Rini Cc: Simon Glass Cc: Ian Campbell Cc: Hans De Goede Cc: Albert Aribaud Cc: Jagan Teki Reviewed-by: Tom Rini Reviewed-by: Simon Glass