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author | Tom Rini <trini@ti.com> | 2015-02-10 10:42:56 -0500 |
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committer | Tom Rini <trini@ti.com> | 2015-02-10 10:42:56 -0500 |
commit | db7a7dee6878fe7539d5967de1caff83246254e0 (patch) | |
tree | 27a94cac552d2015cc53cd29658f15f834475a5c /doc | |
parent | c956662cc3e2475b451afa9a8b639c0ccc49d432 (diff) | |
parent | ba877efb802edb7080703e4dd99e51a437e44f26 (diff) | |
download | u-boot-imx-db7a7dee6878fe7539d5967de1caff83246254e0.zip u-boot-imx-db7a7dee6878fe7539d5967de1caff83246254e0.tar.gz u-boot-imx-db7a7dee6878fe7539d5967de1caff83246254e0.tar.bz2 |
Merge branch 'master' of git://git.denx.de/u-boot-x86
Diffstat (limited to 'doc')
-rw-r--r-- | doc/README.x86 | 137 |
1 files changed, 128 insertions, 9 deletions
diff --git a/doc/README.x86 b/doc/README.x86 index 7df8cc5..fb87682 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -18,11 +18,11 @@ U-Boot supports running as a coreboot [1] payload on x86. So far only Link on other x86 boards since coreboot deals with most of the low-level details. U-Boot also supports booting directly from x86 reset vector without coreboot, -aka raw support or bare support. Currently Link and Intel Crown Bay board -support running U-Boot 'bare metal'. +aka raw support or bare support. Currently Link, Intel Crown Bay, Intel +Minnowboard Max and Intel Galileo support running U-Boot 'bare metal'. -As for loading 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. +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. Build Instructions ------------------ @@ -47,13 +47,15 @@ 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. -Building ROM version of U-Boot (hereafter referred to as u-boot.rom) is a +Building a ROM version of U-Boot (hereafter referred to as u-boot.rom) is a little bit tricky, as generally it requires several binary blobs which are not shipped in the U-Boot source tree. Due to this reason, the u-boot.rom build is not turned on by default in the U-Boot source tree. Firstly, you need turn it -on by uncommenting the following line in the main U-Boot Makefile: +on by enabling the ROM build: -# ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom +$ export BUILD_ROM=y + +This tells the Makefile to build u-boot.rom as a target. Link-specific instructions: @@ -108,6 +110,50 @@ Now you can build U-Boot and obtain u-boot.rom $ make crownbay_defconfig $ make all +Intel Minnowboard Max instructions: + +This uses as FSP as with Crown Bay, except it is for the Atom E3800 series. +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 + +Obtain the VGA RAM (Vga.dat at the time of writing) and put it into the same +directory: board/intel/minnowmax/vga.bin + +You still need two more binary blobs. These come from the sample SPI image +provided in the FSP (SPI.bin at the time of writing). + +Use ifdtool in the U-Boot tools directory to extract the images from that +file, for example: + + $ ./tools/ifdtool -x BayleyBay/SPI.bin + $ cp flashregion_2_intel_me.bin board/intel/minnowmax/me.bin + $ cp flashregion_0_flashdescriptor.bin board/intel/minnowmax/descriptor.bin + +Now you can build U-Boot and obtain u-boot.rom + +$ make minnowmax_defconfig +$ make all + +Intel Galileo instructions: + +Only one binary blob is needed for Remote Management Unit (RMU) within Intel +Quark SoC. Not like FSP, U-Boot does not call into the binary. The binary is +needed by the Quark SoC itself. + +You can get the binary blob from Quark Board Support Package from Intel website: + +* ./QuarkSocPkg/QuarkNorthCluster/Binary/QuarkMicrocode/RMU.bin + +Rename the file and put it to the board directory by: + + $ cp RMU.bin board/intel/galileo/rmu.bin + +Now you can build U-Boot and obtain u-boot.rom + +$ make galileo_defconfig +$ make all + Test with coreboot ------------------ For testing U-Boot as the coreboot payload, there are things that need be paid @@ -126,11 +172,21 @@ Make sure 0x1110000 matches CONFIG_SYS_TEXT_BASE and 0x1110015 matches the symbol address of _start (in arch/x86/cpu/start.S). If you want to use ELF as the coreboot payload, change U-Boot configuration to -use CONFIG_OF_EMBED. +use CONFIG_OF_EMBED instead of CONFIG_OF_SEPARATE. + +To enable video you must enable these options in coreboot: + + - Set framebuffer graphics resolution (1280x1024 32k-color (1:5:5)) + - Keep VESA framebuffer + +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. + CPU Microcode ------------- -Modern CPU usually requires a special bit stream called microcode [5] to be +Modern CPUs usually require a special bit stream called microcode [5] to be loaded on the processor after power up in order to function properly. U-Boot has already integrated these as hex dumps in the source tree. @@ -162,6 +218,69 @@ mtrr - List and set the Memory Type Range Registers (MTRR). These are used to mode to use. U-Boot sets up some reasonable values but you can adjust then with this command. +Development Flow +---------------- +These notes are for those who want to port U-Boot to a new x86 platform. + +Since x86 CPUs boot from SPI flash, a SPI flash emulator is a good investment. +The Dediprog em100 can be used on Linux. The em100 tool is available here: + + http://review.coreboot.org/p/em100.git + +On Minnowboard Max the following command line can be used: + + sudo em100 -s -p LOW -d u-boot.rom -c W25Q64DW -r + +A suitable clip for connecting over the SPI flash chip is here: + + http://www.dediprog.com/pd/programmer-accessories/EM-TC-8 + +This allows you to override the SPI flash contents for development purposes. +Typically you can write to the em100 in around 1200ms, considerably faster +than programming the real flash device each time. The only important +limitation of the em100 is that it only supports SPI bus speeds up to 20MHz. +This means that images must be set to boot with that speed. This is an +Intel-specific feature - e.g. tools/ifttool has an option to set the SPI +speed in the SPI descriptor region. + +If your chip/board uses an Intel Firmware Support Package (FSP) it is fairly +easy to fit it in. You can follow the Minnowboard Max implementation, for +example. Hopefully you will just need to create new files similar to those +in arch/x86/cpu/baytrail which provide Bay Trail support. + +If you are not using an FSP you have more freedom and more responsibility. +The ivybridge support works this way, although it still uses a ROM for +graphics and still has binary blobs containing Intel code. You should aim to +support all important peripherals on your platform including video and storage. +Use the device tree for configuration where possible. + +For the microcode you can create a suitable device tree file using the +microcode tool: + + ./tools/microcode-tool -d microcode.dat create <model> + +or if you only have header files and not the full Intel microcode.dat database: + + ./tools/microcode-tool -H BAY_TRAIL_FSP_KIT/Microcode/M0130673322.h \ + -H BAY_TRAIL_FSP_KIT/Microcode/M0130679901.h \ + create all + +These are written to arch/x86/dts/microcode/ by default. + +Note that it is possible to just add the micrcode for your CPU if you know its +model. U-Boot prints this information when it starts + + CPU: x86_64, vendor Intel, device 30673h + +so here we can use the M0130673322 file. + +If you platform can display POST codes on two little 7-segment displays on +the board, then you can use post_code() calls from C or assembler to monitor +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. + TODO List --------- - Audio |