X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=doc%2FREADME.x86;h=c96a22cb08d8ba4a594c94a136285b5098b0029f;hb=0d7f1ae0fe6c0d9af2c0208aab4843ec3fdfaf52;hp=c5c3010ee2ba392ad6b82fa21479cac91b4d0f3a;hpb=312a6c016a2d81aa3fbc605f5c0c315b6a4e3464;p=u-boot diff --git a/doc/README.x86 b/doc/README.x86 index c5c3010ee2..c96a22cb08 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -18,12 +18,16 @@ U-Boot supports running as a coreboot [1] payload on x86. So far only Link work with minimal adjustments on other x86 boards since coreboot deals with most of the low-level details. +U-Boot is a main bootloader on Intel Edison board. + U-Boot also supports booting directly from x86 reset vector, without coreboot. In this case, known as bare mode, from the fact that it runs on the 'bare metal', U-Boot acts like a BIOS replacement. The following platforms are supported: - - Bayley Bay + - Bayley Bay CRB + - Cherry Hill CRB + - Congatec QEVAL 2.0 & conga-QA3/E3845 - Cougar Canyon 2 CRB - Crown Bay CRB - Galileo @@ -60,6 +64,16 @@ 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 +------------------------------------------------ + +Intel Edison instructions: + +Simple you can build U-Boot and obtain u-boot.bin + +$ make edison_defconfig +$ make all + Build Instructions for U-Boot as BIOS replacement (bare mode) ------------------------------------------------------------- Building a ROM version of U-Boot (hereafter referred to as u-boot.rom) is a @@ -303,16 +317,49 @@ Offset Description Controlling config 000000 descriptor.bin Hard-coded to 0 in ifdtool 001000 me.bin Set by the descriptor 500000 +6ef000 Environment CONFIG_ENV_OFFSET 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 7f8000 (depends on size of fsp.bin) -7fe000 Environment CONFIG_ENV_OFFSET 7ff800 U-Boot 16-bit boot CONFIG_SYS_X86_START16 Overall ROM image size is controlled by CONFIG_ROM_SIZE. +Note that the debug version of the FSP is bigger in size. If this version +is used, CONFIG_FSP_ADDR needs to be configured to 0xfffb0000 instead of +the default value 0xfffc0000. + +--- + +Intel Cherry Hill specific instructions for bare mode: + +This uses Intel FSP for Braswell platform. Download it from Intel FSP website, +put the .fd file to the board directory and rename it to fsp.bin. + +Extract descriptor.bin and me.bin from the original BIOS on the board using +ifdtool and put them to the board directory as well. + +Note the FSP package for Braswell does not ship a traditional legacy VGA BIOS +image for the integrated graphics device. Instead a new binary called Video +BIOS Table (VBT) is shipped. Put it to the board directory and rename it to +vbt.bin if you want graphics support in U-Boot. + +Now you can build U-Boot and obtain u-boot.rom + +$ make cherryhill_defconfig +$ make all + +An important note for programming u-boot.rom to the on-board SPI flash is that +you need make sure the SPI flash's 'quad enable' bit in its status register +matches the settings in the descriptor.bin, otherwise the board won't boot. + +For the on-board SPI flash MX25U6435F, this can be done by writing 0x40 to the +status register by DediProg in: Config > Modify Status Register > Write Status +Register(s) > Register1 Value(Hex). This is is a one-time change. Once set, it +persists in SPI flash part regardless of the u-boot.rom image burned. + --- Intel Galileo instructions for bare mode: @@ -376,10 +423,17 @@ To enable video you must enable these options in coreboot: - 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 @@ -412,18 +466,19 @@ 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. 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: +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, which 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: +Then start QEMU, in U-Boot command line use the following U-Boot command to +setup kernel: => qfw qfw - QEMU firmware interface @@ -437,10 +492,37 @@ qfw => 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: +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 +=> zboot 01000000 - 04000000 1b1ab50 + +Updating U-Boot on Edison +------------------------- +By default Intel Edison boards are shipped with preinstalled heavily +patched U-Boot v2014.04. Though it supports DFU which we may be able to +use. + +1. Prepare u-boot.bin as described in chapter above. You still need one +more step (if and only if you have original U-Boot), i.e. run the +following command: + +$ truncate -s %4096 u-boot.bin + +2. Run your board and interrupt booting to U-Boot console. In the console +call: + + => run do_force_flash_os + +3. Wait for few seconds, it will prepare environment variable and runs +DFU. Run DFU command from the host system: + +$ dfu-util -v -d 8087:0a99 --alt u-boot0 -D u-boot.bin + +4. Return to U-Boot console and following hint. i.e. push Ctrl+C, and +reset the board: + + => reset CPU Microcode ------------- @@ -490,8 +572,8 @@ Booting Ubuntu -------------- As an example of how to set up your boot flow with U-Boot, here are instructions for starting Ubuntu from U-Boot. These instructions have been -tested on Minnowboard MAX with a SATA driver but are equally applicable on -other platforms and other media. There are really only four steps and its a +tested on Minnowboard MAX with a SATA drive but are equally applicable on +other platforms and other media. There are really only four steps and it's a very simple script, but a more detailed explanation is provided here for completeness. @@ -499,7 +581,7 @@ Note: It is possible to set up U-Boot to boot automatically using syslinux. It could also use the grub.cfg file (/efi/ubuntu/grub.cfg) to obtain the GUID. If you figure these out, please post patches to this README. -Firstly, you will need Ubunutu installed on an available disk. It should be +Firstly, you will need Ubuntu installed on an available disk. It should be possible to make U-Boot start a USB start-up disk but for now let's assume that you used another boot loader to install Ubuntu. @@ -659,7 +741,7 @@ U-Boot: Loading bzImage at address 100000 (5805728 bytes) Magic signature found Initial RAM disk at linear address 0x04000000, size 19215259 bytes - Kernel command line: "console=ttyS0,115200 root=/dev/disk/by-partuuid/965c59ee-1822-4326-90d2-b02446050059 ro" + Kernel command line: "root=/dev/disk/by-partuuid/965c59ee-1822-4326-90d2-b02446050059 ro" Starting kernel ... @@ -679,13 +761,14 @@ above commands into a script since then it will be faster. 240,329 ahci 1,422,704 vesa display -Now the kernel actually starts: +Now the kernel actually starts: (if you want to examine kernel boot up message +on the serial console, append "console=ttyS0,115200" to the kernel command line) [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Initializing cgroup subsys cpuacct [ 0.000000] Linux version 3.13.0-58-generic (buildd@allspice) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #97-Ubuntu SMP Wed Jul 8 02:56:15 UTC 2015 (Ubuntu 3.13.0-58.97-generic 3.13.11-ckt22) - [ 0.000000] Command line: console=ttyS0,115200 root=/dev/disk/by-partuuid/965c59ee-1822-4326-90d2-b02446050059 ro + [ 0.000000] Command line: root=/dev/disk/by-partuuid/965c59ee-1822-4326-90d2-b02446050059 ro console=ttyS0,115200 It continues for a long time. Along the way you will see it pick up your ramdisk: @@ -736,22 +819,10 @@ If you want to put this in a script you can use something like this: The \ is to tell the shell not to evaluate ${filesize} as part of the setenv command. -You will also need to add this to your board configuration file, e.g. -include/configs/minnowmax.h: - - #define CONFIG_BOOTDELAY 2 - -Now when you reset your board it wait a few seconds (in case you want to -interrupt) and then should boot straight into Ubuntu. - You can also bake this behaviour into your build by hard-coding the environment variables if you add this to minnowmax.h: -#undef CONFIG_BOOTARGS #undef CONFIG_BOOTCOMMAND - -#define CONFIG_BOOTARGS \ - "root=/dev/sda2 ro" #define CONFIG_BOOTCOMMAND \ "ext2load scsi 0:2 03000000 /boot/vmlinuz-3.13.0-58-generic; " \ "ext2load scsi 0:2 04000000 /boot/initrd.img-3.13.0-58-generic; " \ @@ -760,6 +831,10 @@ environment variables if you add this to minnowmax.h: #undef CONFIG_EXTRA_ENV_SETTINGS #define CONFIG_EXTRA_ENV_SETTINGS "boot=zboot 03000000 0 04000000 ${filesize}" +and change CONFIG_BOOTARGS value in configs/minnowmax_defconfig to: + +CONFIG_BOOTARGS="root=/dev/sda2 ro" + Test with SeaBIOS ----------------- SeaBIOS [14] is an open source implementation of a 16-bit x86 BIOS. It can run @@ -812,6 +887,30 @@ to install/boot a Windows XP OS (below for example command to install Windows). This is also tested on Intel Crown Bay board with a PCIe graphics card, booting SeaBIOS then chain-loading a GRUB on a USB drive, then Linux kernel finally. +If you are using Intel Integrated Graphics Device (IGD) as the primary display +device on your board, SeaBIOS needs to be patched manually to get its VGA ROM +loaded and run by SeaBIOS. SeaBIOS locates VGA ROM via the PCI expansion ROM +register, but IGD device does not have its VGA ROM mapped by this register. +Its VGA ROM is packaged as part of u-boot.rom at a configurable flash address +which is unknown to SeaBIOS. An example patch is needed for SeaBIOS below: + +diff --git a/src/optionroms.c b/src/optionroms.c +index 65f7fe0..c7b6f5e 100644 +--- a/src/optionroms.c ++++ b/src/optionroms.c +@@ -324,6 +324,8 @@ init_pcirom(struct pci_device *pci, int isvga, u64 *sources) + rom = deploy_romfile(file); + else if (RunPCIroms > 1 || (RunPCIroms == 1 && isvga)) + rom = map_pcirom(pci); ++ if (pci->bdf == pci_to_bdf(0, 2, 0)) ++ rom = (struct rom_header *)0xfff90000; + if (! rom) + // No ROM present. + return; + +Note: the patch above expects IGD device is at PCI b.d.f 0.2.0 and its VGA ROM +is at 0xfff90000 which corresponds to CONFIG_VGA_BIOS_ADDR on Minnowboard MAX. +Change these two accordingly if this is not the case on your board. Development Flow ---------------- @@ -963,12 +1062,103 @@ transformations. Remember to add attribution to coreboot for new files added to U-Boot. This should go at the top of each file and list the coreboot filename where the code originated. +Debugging ACPI issues with Windows: + +Windows might cache system information and only detect ACPI changes if you +modify the ACPI table versions. So tweak them liberally when debugging ACPI +issues with Windows. + +ACPI Support Status +------------------- +Advanced Configuration and Power Interface (ACPI) [16] aims to establish +industry-standard interfaces enabling OS-directed configuration, power +management, and thermal management of mobile, desktop, and server platforms. + +Linux can boot without ACPI with "acpi=off" command line parameter, but +with ACPI the kernel gains the capabilities to handle power management. +For Windows, ACPI is a must-have firmware feature since Windows Vista. +CONFIG_GENERATE_ACPI_TABLE is the config option to turn on ACPI support in +U-Boot. This requires Intel ACPI compiler to be installed on your host to +compile ACPI DSDT table written in ASL format to AML format. You can get +the compiler via "apt-get install iasl" if you are on Ubuntu or download +the source from [17] to compile one by yourself. + +Current ACPI support in U-Boot is basically complete. More optional features +can be added in the future. The status as of today is: + + * Support generating RSDT, XSDT, FACS, FADT, MADT, MCFG tables. + * Support one static DSDT table only, compiled by Intel ACPI compiler. + * Support S0/S3/S4/S5, reboot and shutdown from OS. + * Support booting a pre-installed Ubuntu distribution via 'zboot' command. + * Support installing and booting Ubuntu 14.04 (or above) from U-Boot with + the help of SeaBIOS using legacy interface (non-UEFI mode). + * Support installing and booting Windows 8.1/10 from U-Boot with the help + of SeaBIOS using legacy interface (non-UEFI mode). + * Support ACPI interrupts with SCI only. + +Features that are optional: + * Dynamic AML bytecodes insertion at run-time. We may need this to support + SSDT table generation and DSDT fix up. + * SMI support. Since U-Boot is a modern bootloader, we don't want to bring + those legacy stuff into U-Boot. ACPI spec allows a system that does not + support SMI (a legacy-free system). + +ACPI was initially enabled on BayTrail based boards. Testing was done by booting +a pre-installed Ubuntu 14.04 from a SATA drive. Installing Ubuntu 14.04 and +Windows 8.1/10 to a SATA drive and booting from there is also tested. Most +devices seem to work correctly and the board can respond a reboot/shutdown +command from the OS. + +For other platform boards, ACPI support status can be checked by examining their +board defconfig files to see if CONFIG_GENERATE_ACPI_TABLE is set to y. + +The S3 sleeping state is a low wake latency sleeping state defined by ACPI +spec where all system context is lost except system memory. To test S3 resume +with a Linux kernel, simply run "echo mem > /sys/power/state" and kernel will +put the board to S3 state where the power is off. So when the power button is +pressed again, U-Boot runs as it does in cold boot and detects the sleeping +state via ACPI register to see if it is S3, if yes it means we are waking up. +U-Boot is responsible for restoring the machine state as it is before sleep. +When everything is done, U-Boot finds out the wakeup vector provided by OSes +and jump there. To determine whether ACPI S3 resume is supported, check to +see if CONFIG_HAVE_ACPI_RESUME is set for that specific board. + +Note for testing S3 resume with Windows, correct graphics driver must be +installed for your platform, otherwise you won't find "Sleep" option in +the "Power" submenu from the Windows start menu. + +EFI Support +----------- +U-Boot supports booting as a 32-bit or 64-bit EFI payload, e.g. with UEFI. +This is enabled with CONFIG_EFI_STUB. 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 kernel (i.e. replaces UEFI completely but +provides the same EFI run-time services) is not currently supported on x86. + +See README.efi for details of EFI support in U-Boot. + +64-bit Support +-------------- +U-Boot supports booting a 64-bit kernel directly and is able to change to +64-bit mode to do so. It also supports (with CONFIG_EFI_STUB) booting from +both 32-bit and 64-bit UEFI. 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. + +Given U-Boot's extensive 64-bit support this has not been a high priority, +but it would be a nice addition. TODO List --------- - Audio - Chrome OS verified boot -- SMI and ACPI support, to provide platform info and facilities to Linux +- Building U-Boot to run in 64-bit mode References ---------- @@ -987,3 +1177,5 @@ References [13] http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf [14] http://www.seabios.org/SeaBIOS [15] doc/device-tree-bindings/misc/intel,irq-router.txt +[16] http://www.acpi.info +[17] https://www.acpica.org/downloads