mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-02 01:19:49 +00:00
8e1c9fe243
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 <sean.anderson@seco.com> |
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| .. | ||
| eeprom | ||
| init | ||
| spl | ||
| autoboot.c | ||
| avb_verify.c | ||
| bloblist.c | ||
| board_f.c | ||
| board_info.c | ||
| board_r.c | ||
| bootstage.c | ||
| bouncebuf.c | ||
| cli.c | ||
| cli_hush.c | ||
| cli_readline.c | ||
| cli_simple.c | ||
| command.c | ||
| console.c | ||
| cros_ec.c | ||
| ddr_spd.c | ||
| dfu.c | ||
| dlmalloc.c | ||
| dlmalloc.src | ||
| edid.c | ||
| event.c | ||
| exports.c | ||
| fdt_simplefb.c | ||
| fdt_support.c | ||
| flash.c | ||
| hash.c | ||
| hwconfig.c | ||
| iomux.c | ||
| iotrace.c | ||
| kallsyms.c | ||
| Kconfig | ||
| kgdb.c | ||
| kgdb_stubs.c | ||
| lcd.c | ||
| lcd_console.c | ||
| lcd_console_rotation.c | ||
| log.c | ||
| log_console.c | ||
| log_syslog.c | ||
| main.c | ||
| Makefile | ||
| malloc_simple.c | ||
| memsize.c | ||
| menu.c | ||
| miiphyutil.c | ||
| qfw.c | ||
| s_record.c | ||
| scp03.c | ||
| splash.c | ||
| splash_source.c | ||
| stackprot.c | ||
| stdio.c | ||
| system_map.c | ||
| update.c | ||
| usb.c | ||
| usb_hub.c | ||
| usb_kbd.c | ||
| usb_storage.c | ||
| xyzModem.c | ||