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.
+U-Boot supports loading an x86 VxWorks kernel. Please check README.vxworks
+for more details.
Build Instructions for U-Boot as coreboot payload
-------------------------------------------------
---
-Intel Minnowboard Max instructions for bare mode:
+Intel Cougar Canyon 2 specific instructions for bare mode:
+
+This uses Intel FSP for 3rd generation Intel Core and Intel Celeron processors
+with mobile Intel HM76 and QM77 chipsets platform. Download it from Intel FSP
+website and put the .fd file (CHIEFRIVER_FSP_GOLD_001_09-OCTOBER-2013.fd at the
+time of writing) in the board directory and rename it to fsp.bin.
+
+Now build U-Boot and obtain u-boot.rom
+
+$ make cougarcanyon2_defconfig
+$ make all
+
+The board has two 8MB SPI flashes mounted, which are called SPI-0 and SPI-1 in
+the board manual. The SPI-0 flash should have flash descriptor plus ME firmware
+and SPI-1 flash is used to store U-Boot. For convenience, the complete 8MB SPI-0
+flash image is included in the FSP package (named Rom00_8M_MB_PPT.bin). Program
+this image to the SPI-0 flash according to the board manual just once and we are
+all set. For programming U-Boot we just need to program SPI-1 flash.
+
+---
+
+Intel Bay Trail based board instructions for bare mode:
This uses as FSP as with Crown Bay, except it is for the Atom E3800 series.
+Two boards that use this configuration are Bayley Bay and Minnowboard MAX.
Download this and get the .fd file (BAYTRAIL_FSP_GOLD_003_16-SEP-2014.fd at
-the time of writing). Put it in the board directory:
-board/intel/minnowmax/fsp.bin
+the time of writing). Put it in the corresponding board directory and rename
+it to fsp.bin.
Obtain the VGA RAM (Vga.dat at the time of writing) and put it into the same
-directory: board/intel/minnowmax/vga.bin
+board directory as vga.bin.
+
+You still need two more binary blobs. For Bayley Bay, they can be extracted
+from the sample SPI image provided in the FSP (SPI.bin at the time of writing).
+
+ $ ./tools/ifdtool -x BayleyBay/SPI.bin
+ $ cp flashregion_0_flashdescriptor.bin board/intel/bayleybay/descriptor.bin
+ $ cp flashregion_2_intel_me.bin board/intel/bayleybay/me.bin
-You still need two more binary blobs. The first comes from the original
-firmware image available from:
+For Minnowboard MAX, we can reuse the same ME firmware above, but for flash
+descriptor, we need get that somewhere else, as the one above does not seem to
+work, probably because it is not designed for the Minnowboard MAX. Now download
+the original firmware image for this board from:
http://firmware.intel.com/sites/default/files/2014-WW42.4-MinnowBoardMax.73-64-bit.bin_Release.zip
$ cp flashregion_0_flashdescriptor.bin board/intel/minnowmax/descriptor.bin
-Then do the same with the sample SPI image provided in the FSP (SPI.bin at
-the time of writing) to obtain the last image. Note that this will also
-produce a flash descriptor file, but it does not seem to work, probably
-because it is not designed for the Minnowmax. That is why you need to get
-the flash descriptor from the original firmware as above.
-
- $ ./tools/ifdtool -x BayleyBay/SPI.bin
- $ cp flashregion_2_intel_me.bin board/intel/minnowmax/me.bin
-
Now you can build U-Boot and obtain u-boot.rom
+Note: below are examples/information for Minnowboard MAX.
$ make minnowmax_defconfig
$ make all
000000 descriptor.bin Hard-coded to 0 in ifdtool
001000 me.bin Set by the descriptor
500000 <spare>
+6f0000 MRC cache CONFIG_ENABLE_MRC_CACHE
700000 u-boot-dtb.bin CONFIG_SYS_TEXT_BASE
790000 vga.bin CONFIG_VGA_BIOS_ADDR
7c0000 fsp.bin CONFIG_FSP_ADDR
$ make galileo_defconfig
$ make all
-QEMU x86 target instructions:
+---
+
+QEMU x86 target instructions for bare mode:
To build u-boot.rom for QEMU x86 targets, just simply run
If you want to check both consoles, use '-serial stdio'.
Multicore is also supported by QEMU via '-smp n' where n is the number of cores
-to instantiate. Currently the default U-Boot built for QEMU supports 2 cores.
-In order to support more cores, you need add additional cpu nodes in the device
-tree and change CONFIG_MAX_CPUS accordingly.
+to instantiate. Note, the maximum supported CPU number in QEMU is 255.
+
+The fw_cfg interface in QEMU also provides information about kernel data, initrd,
+command-line arguments and more. U-Boot supports directly accessing these informtion
+from fw_cfg interface, this saves the time of loading them from hard disk or
+network again, through emulated devices. To use it , simply providing them in
+QEMU command line:
+
+$ qemu-system-i386 -nographic -bios path/to/u-boot.rom -m 1024 -kernel /path/to/bzImage
+ -append 'root=/dev/ram console=ttyS0' -initrd /path/to/initrd -smp 8
+
+Note: -initrd and -smp are both optional
+
+Then start QEMU, in U-Boot command line use the following U-Boot command to setup kernel:
+
+ => qfw
+qfw - QEMU firmware interface
+
+Usage:
+qfw <command>
+ - list : print firmware(s) currently loaded
+ - cpus : print online cpu number
+ - load <kernel addr> <initrd addr> : load kernel and initrd (if any) and setup for zboot
+
+=> qfw load
+loading kernel to address 01000000 size 5d9d30 initrd 04000000 size 1b1ab50
+
+Here the kernel (bzImage) is loaded to 01000000 and initrd is to 04000000. Then, 'zboot'
+can be used to boot the kernel:
+
+=> zboot 02000000 - 04000000 1b1ab50
CPU Microcode
-------------
adjust internal settings, there are several x86-specific commands that may be
useful:
-hob - Display information about Firmware Support Package (FSP) Hand-off
- Block. This is only available on platforms which use FSP, mostly
- Atom.
+fsp - Display information about Intel Firmware Support Package (FSP).
+ This is only available on platforms which use FSP, mostly Atom.
iod - Display I/O memory
iow - Write I/O memory
mtrr - List and set the Memory Type Range Registers (MTRR). These are used to
boot progress. This can be good for debugging.
If not, you can try to get serial working as early as possible. The early
-debug serial port may be useful here. See setup_early_uart() for an example.
+debug serial port may be useful here. See setup_internal_uart() for an example.
During the U-Boot porting, one of the important steps is to write correct PIRQ
routing information in the board device tree. Without it, device drivers in the
PCI_BDF(0, 3, 0) INTA PIRQA
...
+Porting Hints
+-------------
+
+Quark-specific considerations:
+
+To port U-Boot to other boards based on the Intel Quark SoC, a few things need
+to be taken care of. The first important part is the Memory Reference Code (MRC)
+parameters. Quark MRC supports memory-down configuration only. All these MRC
+parameters are supplied via the board device tree. To get started, first copy
+the MRC section of arch/x86/dts/galileo.dts to your board's device tree, then
+change these values by consulting board manuals or your hardware vendor.
+Available MRC parameter values are listed in include/dt-bindings/mrc/quark.h.
+The other tricky part is with PCIe. Quark SoC integrates two PCIe root ports,
+but by default they are held in reset after power on. In U-Boot, PCIe
+initialization is properly handled as per Quark's firmware writer guide.
+In your board support codes, you need provide two routines to aid PCIe
+initialization, which are board_assert_perst() and board_deassert_perst().
+The two routines need implement a board-specific mechanism to assert/deassert
+PCIe PERST# pin. Care must be taken that in those routines that any APIs that
+may trigger PCI enumeration process are strictly forbidden, as any access to
+PCIe root port's configuration registers will cause system hang while it is
+held in reset. For more details, check how they are implemented by the Intel
+Galileo board support codes in board/intel/galileo/galileo.c.
+
TODO List
---------
- Audio