diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/psci-lib-integration-guide.md | 14 | ||||
| -rw-r--r-- | docs/user-guide.md | 9 |
2 files changed, 17 insertions, 6 deletions
diff --git a/docs/psci-lib-integration-guide.md b/docs/psci-lib-integration-guide.md index f290966b..d81b3286 100644 --- a/docs/psci-lib-integration-guide.md +++ b/docs/psci-lib-integration-guide.md @@ -176,7 +176,9 @@ interfaces are: * The page tables must be setup and the MMU enabled * The C runtime environment must be setup and stack initialized * The Data cache must be enabled prior to invoking any of the PSCI library - interfaces except for `psci_warmboot_entrypoint()`. + interfaces except for `psci_warmboot_entrypoint()`. For + `psci_warmboot_entrypoint()`, if the build option `HW_ASSISTED_COHERENCY` + is enabled however, data caches are expected to be enabled. Further requirements for each interface can be found in the interface description. @@ -270,11 +272,11 @@ wakes up, it will start execution from the warm reset address. Return : void This function performs the warm boot initialization/restoration as mandated by -[PSCI spec]. For AArch32, on wakeup from power down the CPU resets to secure -SVC mode and the EL3 Runtime Software must perform the prerequisite -initializations mentioned at top of this section. This function must be called -with Data cache disabled but with MMU initialized and enabled. The major -actions performed by this function are: +[PSCI spec]. For AArch32, on wakeup from power down the CPU resets to secure SVC +mode and the EL3 Runtime Software must perform the prerequisite initializations +mentioned at top of this section. This function must be called with Data cache +disabled (unless build option `HW_ASSISTED_COHERENCY` is enabled) but with MMU +initialized and enabled. The major actions performed by this function are: * Invalidates the stack and enables the data cache. * Initializes architecture and PSCI state coordination. diff --git a/docs/user-guide.md b/docs/user-guide.md index 9d91c2a9..c6c8e19b 100644 --- a/docs/user-guide.md +++ b/docs/user-guide.md @@ -328,6 +328,15 @@ performed. * `HANDLE_EA_EL3_FIRST`: When defined External Aborts and SError Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. +* `HW_ASSISTED_COHERENCY`: On most ARM systems to-date, platform-specific + software operations are required for CPUs to enter and exit coherency. + However, there exists newer systems where CPUs' entry to and exit from + coherency is managed in hardware. Such systems require software to only + initiate the operations, and the rest is managed in hardware, minimizing + active software management. In such systems, this boolean option enables ARM + Trusted Firmware to carry out build and run-time optimizations during boot + and power management operations. This option defaults to 0. + * `LOAD_IMAGE_V2`: Boolean option to enable support for new version (v2) of image loading, which provides more flexibility and scalability around what images are loaded and executed during boot. Default is 0. |