- Link (Chromebook Pixel)
- Minnowboard MAX
- Samus (Chromebook Pixel 2015)
- - QEMU x86
+ - QEMU x86 (32-bit & 64-bit)
As for loading an OS, U-Boot supports directly booting a 32-bit or 64-bit
Linux kernel as part of a FIT image. It also supports a compressed zImage.
$ make coreboot_defconfig
$ make all
-Note this default configuration will build a U-Boot payload for the QEMU board.
-To build a coreboot payload against another board, you can change the build
-configuration during the 'make menuconfig' process.
-
-x86 architecture --->
- ...
- (qemu-x86) Board configuration file
- (qemu-x86_i440fx) Board Device Tree Source (dts) file
- (0x01920000) Board specific Cache-As-RAM (CAR) address
- (0x4000) Board specific Cache-As-RAM (CAR) size
-
-Change the 'Board configuration file' and 'Board Device Tree Source (dts) file'
-to point to a new board. You can also change the Cache-As-RAM (CAR) related
-settings here if the default values do not fit your new board.
-
Build Instructions for U-Boot as main bootloader
------------------------------------------------
em100 -s -d filename.rom -c W25Q64CV -r
+Flash map for samus / broadwell:
+
+ fffff800 SYS_X86_START16
+ ffff0000 RESET_SEG_START
+ fffd8000 TPL_TEXT_BASE
+ fffa0000 X86_MRC_ADDR
+ fff90000 VGA_BIOS_ADDR
+ ffed0000 SYS_TEXT_BASE
+ ffea0000 X86_REFCODE_ADDR
+ ffe70000 SPL_TEXT_BASE
+ ffbf8000 CONFIG_ENV_OFFSET (environemnt offset)
+ ffbe0000 rw-mrc-cache (Memory-reference-code cache)
+ ffa00000 <spare>
+ ff801000 intel-me (address set by descriptor.bin)
+ ff800000 intel-descriptor
+
---
Intel Crown Bay specific instructions for bare mode:
To build u-boot.rom for QEMU x86 targets, just simply run
-$ make qemu-x86_defconfig
+$ make qemu-x86_defconfig (for 32-bit)
+or
+$ make qemu-x86_64_defconfig (for 64-bit)
$ make all
Note this default configuration will build a U-Boot for the QEMU x86 i440FX
- Set framebuffer graphics resolution (1280x1024 32k-color (1:5:5))
- Keep VESA framebuffer
-And include coreboot_fb.dtsi in your board's device tree source file, like:
-
- /include/ "coreboot_fb.dtsi"
-
At present it seems that for Minnowboard Max, coreboot does not pass through
the video information correctly (it always says the resolution is 0x0). This
works correctly for link though.
-Note: coreboot framebuffer driver does not work on QEMU. The reason is unknown
-at this point. Patches are welcome if you figure out anything wrong.
-
Test with QEMU for bare mode
----------------------------
QEMU is a fancy emulator that can enable us to test U-Boot without access to
=> zboot 01000000 - 04000000 1b1ab50
+To run 64-bit U-Boot, qemu-system-x86_64 should be used instead, e.g.:
+$ qemu-system-x86_64 -nographic -bios path/to/u-boot.rom
+
+A specific CPU can be specified via the '-cpu' parameter but please make
+sure the specified CPU supports 64-bit like '-cpu core2duo'. Conversely
+'-cpu pentium' won't work for obvious reasons that the processor only
+supports 32-bit.
+
+Note 64-bit support is very preliminary at this point. Lots of features
+are missing in the 64-bit world. One notable feature is the VGA console
+support which is currently missing, so that you must specify '-nographic'
+to get 64-bit U-Boot up and running.
+
Updating U-Boot on Edison
-------------------------
By default Intel Edison boards are shipped with preinstalled heavily
U-Boot supports booting as a 32-bit or 64-bit EFI payload, e.g. with UEFI.
This is enabled with CONFIG_EFI_STUB to boot from both 32-bit and 64-bit
UEFI BIOS. U-Boot can also run as an EFI application, with CONFIG_EFI_APP.
-The CONFIG_EFI_LOADER option, where U-Booot provides an EFI environment to
+The CONFIG_EFI_LOADER option, where U-Boot provides an EFI environment to
the kernel (i.e. replaces UEFI completely but provides the same EFI run-time
-services) is not currently supported on x86.
+services) is supported too. For example, we can even use 'bootefi' command
+to load a 'u-boot-payload.efi', see below test logs on QEMU.
-See README.u-boot_on_efi and README.uefi for details of EFI support in U-Boot.
+ => load ide 0 3000000 u-boot-payload.efi
+ 489787 bytes read in 138 ms (3.4 MiB/s)
+ => bootefi 3000000
+ Scanning disk ide.blk#0...
+ Found 2 disks
+ WARNING: booting without device tree
+ ## Starting EFI application at 03000000 ...
+ U-Boot EFI Payload
-64-bit Support
---------------
-U-Boot supports booting a 64-bit kernel directly and is able to change to
-64-bit mode to do so. However, U-Boot itself is currently always built
-in 32-bit mode. Some access to the full memory range is provided with
-arch_phys_memset().
-The development work to make U-Boot itself run in 64-bit mode has not yet
-been attempted. The best approach would likely be to build a 32-bit SPL
-image for U-Boot, with CONFIG_SPL_BUILD. This could then handle the early CPU
-init in 16-bit and 32-bit mode, running the FSP and any other binaries that
-are needed. Then it could change to 64-bit model and jump to U-Boot proper.
+ U-Boot 2018.07-rc2 (Jun 23 2018 - 17:12:58 +0800)
+
+ CPU: x86_64, vendor AMD, device 663h
+ DRAM: 2 GiB
+ MMC:
+ Video: 1024x768x32
+ Model: EFI x86 Payload
+ Net: e1000: 52:54:00:12:34:56
-Given U-Boot's extensive 64-bit support this has not been a high priority,
-but it would be a nice addition.
+ Warning: e1000#0 using MAC address from ROM
+ eth0: e1000#0
+ No controllers found
+ Hit any key to stop autoboot: 0
+
+See README.u-boot_on_efi and README.uefi for details of EFI support in U-Boot.
TODO List
---------
- Audio
- Chrome OS verified boot
-- Building U-Boot to run in 64-bit mode
References
----------
projects / oweals / u-boot.git / blobdiff