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c93a75a5ab
The PCI_INTR table is an Index/Data pair of I/O ports 0xC00 and 0xC01. This table is responsible for physically routing IRQs to the PIC and IOAPIC. The settings given in this table are chipset and mainboard dependent, so the table values will reside in the mainboard.c file. This allows for a system to uniquely set its IRQ routing. The function to write the PCI_INTR table resides in cimx_util.c because the indices into the table have the same definitions for all SBx00 FCH chipsets. The next piece is a function that will read the PCI_INTR table and program the INT_LINE and INT_PIN registers in PCI config space appropriately. This function will read a devices' INT_PIN register, which is always hardcoded to a value if it uses hardware interrupts. It then uses this value, along with the device and function numbers to determine an index into the PCI_INTR table. It will read the table and program the corresponding value into the PCI config space register 0x3C, INT_LINE. Finally, it will set this IRQ number to LEVEL_TRIGGERED on the PIC because it is a PCI device interrupt and the must be level triggered. For example, the SB800 USB EHCI device 0:18.2 has an INT_PIN value hardcoded to 2. This corresponds to PIN B. On the Persimmon mainboard, I want the USB device to use IRQ 11. I will program the PCI_INTR table at index 0x31 (this USB device index) to 11. This function will then read the INT_PIN register, read the PCI_INTR table, and then program the INT_LINE register with the value it read. It will then set the IRQ on the PIC to LEVEL_TRIGGERED by writing a 1 to I/O port 0x4D1 at bit position 4. Also, the SB700 has slightly different register definitions than the newer SB800 and SB900 so it needs its own set of #defines for the pci_intr registers. Only the Persimmon mainboard is adapted to this change as an example for other mainboards. Change-Id: I6de858289a17fa1e1abacf6328ea5099be74b1d6 Signed-off-by: Mike Loptien <mike.loptien@se-eng.com> Reviewed-on: http://review.coreboot.org/5877 Tested-by: build bot (Jenkins) Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com> |
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| Makefile | ||
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| README | ||
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------------------------------------------------------------------------------- coreboot README ------------------------------------------------------------------------------- coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload. With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required. coreboot was formerly known as LinuxBIOS. Payloads -------- After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot. See http://www.coreboot.org/Payloads for a list of supported payloads. Supported Hardware ------------------ coreboot supports a wide range of chipsets, devices, and mainboards. For details please consult: * http://www.coreboot.org/Supported_Motherboards * http://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * gcc / g++ * make Optional: * doxygen (for generating/viewing documentation) * iasl (for targets with ACPI support) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig') * flex and bison (for regenerating parsers) Building coreboot ----------------- Please consult http://www.coreboot.org/Build_HOWTO for details. Testing coreboot Without Modifying Your Hardware ------------------------------------------------ If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU. Please see http://www.coreboot.org/QEMU for details. Website and Mailing List ------------------------ Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website: http://www.coreboot.org You can contact us directly on the coreboot mailing list: http://www.coreboot.org/Mailinglist Copyright and License --------------------- The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details. coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details. This makes the resulting coreboot images licensed under the GPL, version 2.