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diff --git a/readme.txt b/readme.txt deleted file mode 100644 index 9569a32..0000000 --- a/readme.txt +++ /dev/null @@ -1,161 +0,0 @@ -This patch to Versatile Express DVD version 5.0 provides -an updated Boot Monitor as well as updated DCC firmware -for the CoreTile Express A15x2 A7x3 (V2P-CA15-A7) processor -board. - -The updates are mandatory to be able to use the unified power -management support for the big.LITTLE MP & CPU migration mode -of operation in the Linaro Linux kernel. These changes will be -introduced in version 13.01 of the kernel. - -The patch contains the following files: - -bm_v519r.axf - Boot Monitor -dbb_v110.ebf - DCC firmware -readme.txt - the text file you are reading now - ------------- -DCC Firmware ------------- - -This release of the DCC firmware is not compatible with pre-13.01 -kernels (i.e. existing releases of the Linaro Linux kernel). -However, the previous version of the DCC firmware (dbb_v107.ebf) -and pre-13.01 releases of the kernel may be used with this release -of the Boot Monitor as mentioned below. - ------------- -Boot Monitor ------------- - -1. Compatibility with Linaro Linux kernel releases. - - Power management support for the TC2 coretile has been reworked for the - 13.01 kernel release. Broadly, this means that per-cpu mailbox registers - are used to a) bringup secondary cpus during smp bringup & b) implement - warm resets. Linux kernel releases prior to 13.01 used the sys_flags - registers (part of the versatile express motherboard memory map) to do - the same. - - The Bootmon firmware is compatible with both 13.01 and the releases - preceding it. Comptability with pre 13.01 Linaro Linux kernels is - referred to as 'backward compatibility'. The mode of operation of - bootmon can be configured by manipulating bit[12] in the SCC register - offset 0x700 (SCC System Information Register) in the board.txt file. - - a. bit[12]=1: Bootmon is compatible with the 13.01 release of the - Linaro linux kernel. It uses per-cpu mailboxes to - implement warm resets & for secondary cpu bringup. - - b. bit[12]=0: Bootmon is compatible with pre 13.01 releases of the - Linaro linux kernel. It uses sys_flags register to - implement warm resets for secondary cpu bringup. - - This bit should be set to 0 if power management support - has been disabled in the Linux kernel configuration. - - To summarize, the following combinations of the firmware and the - linux kernel are expected to be compatible: - - a. dbb_v107.ebf (dcc fw) + bm_v519r.axf (bootmon fw) + pre-13.01 - release of the Linaro linux kernel + board.txt which has bit[12] - of SCC register offset 0x700 unset. - - b. dbb_v110.ebf (dcc fw) + bm_v519r.axf (bootmon fw) + 13.01 release - of the Linaro linux kernel + board.txt which has bit[12] of SCC - register offset 0x700 set. - -2. Support for TC2 coretile event propagation errata - - The TC2 coretile has a bug in the implementation of the logic - that's responsible for delivering events (e.g. generated by the - 'sev' instruction) across the A15 and A7 clusters. Inter-cluster - events can be lost if the two clusters are operating at certain - OPP (operating point) combinations. This can cause a CPU to wait - for an event ('wfe' instruction) indefinitely e.g. while trying to - acquire a spin lock in the linux kernel. - - Bootmon can be configured to work around this issue. This is done - by generating a periodic event stream (every 32K cycles) on each CPU - to make up for any lost events. Configuration is done by manipulating - the following bits of the SCC register offset 0x700 (SCC System - information register) in the board.txt as follows: - - a. bit[14]=1: Each A15 cpu generates an event stream every 32K cycles. - - b. bit[14]=0: Event stream generation is not configured on the A15 cpus. - - c. bit[15]=1: Each A7 cpu generates an event stream every 32K cycles. - - f. bit[15]=0: Event stream generation is not configured on the A7 cpus. - - Setting both the bits in the SCC register is expected to provide a reliable - workaround of the errata. - -3. Support for powering down the non-boot cluster. - - To save power it might be desirable to keep the non-boot cluster powered - down till the operating system (Linux) does not explicitly bringup cpus - in that cluster either as a part of smp bringup or through a hotplug request. - - Bootmon can be configured to power down the non-boot cluster by manipulating - the SCC register offset 0x700 (SCC System information register) in the - board.txt as follows: - - a. bit[13]=1: Bootmon powers down the non-boot cluster. - - b. bit[13]=0: Bootmon does not power down the non-boot cluster. - - ------------- -Installation ------------- - -There is no automatic installation method for this patch. -To install the patch you must manually copy the files on -to the Micro-SD card of your Versatile Express motherboard, -and then update the relevant image.txt and board.txt files -so that they point to the updated firmware and Boot Monitor. - -Proceed as follows: - -1) copy bm_v519r.axf to the motherboard in this location: - - \SOFTWARE\bm_v519r.axf - - -2) copy dbb_v110.ebf to the motherboard in this location: - - \SITE1\HBI0249A\dbb_v110.ebf - - -3) edit the file on the motherboard: - - \SITE1\HBI0249A\board.txt - - to change the line: - - M0FILE: dbb_v107.ebf ;DCC0 Filename - - so that it becomes: - - M0FILE: dbb_v110.ebf ;DCC0 Filename - - -4) edit the file on the motherboard: - - \SITE1\HBI0249A\images.txt - - to change the line: - - NOR0FILE: \SOFTWARE\bm_v517r.axf ;Image File Name - - so that it becomes: - - NOR0FILE: \SOFTWARE\bm_v519r.axf ;Image File Name - - -It is possible that additional changes to these text -files will be needed - please see the instructions that -come with the Linaro kernel for details of any further -changes that are necessary. |