000000 descriptor.bin Hard-coded to 0 in ifdtool
001000 me.bin Set by the descriptor
500000 <spare>
+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 <spare> (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 Galileo instructions for bare mode:
- 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
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
CPU Microcode
-------------
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
----------------
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
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 not complete. More features will be added
-in the future. The status as of today is:
+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/S5, reboot and shutdown from OS.
+ * 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 not supported so far (to make it a complete ACPI solution):
- * S3 (Suspend to RAM), S4 (Suspend to Disk).
- * Install and boot Ubuntu 14.04 (or above) from U-Boot with legacy interface.
- * Install and boot Windows 8.1/10 from U-Boot with legacy interface.
-
Features that are optional:
- * ACPI global NVS support. We may need it to simplify ASL code logic if
- utilizing NVS variables. Most likely we will need this sooner or later.
* 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).
-So far ACPI is enabled on BayTrail based boards. Testing was done by booting
-a pre-installed Ubuntu 14.04 from a SATA drive. Most devices seem to work
-correctly and the board can respond a reboot/shutdown command from Ubuntu.
+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
+- Building U-Boot to run in 64-bit mode
References
----------
projects / people / ms / u-boot.git / blobdiff