From ec321094f68d3fbfd13b2514aaa6405b1bcd4886 Mon Sep 17 00:00:00 2001 From: Rizwan Qureshi Date: Fri, 6 Sep 2019 20:28:43 +0530 Subject: soc/intel/common/basecode: Implement CSE update flow The following changes are done in this patch: 1. Get the CSE partition info containing version of CSE RW using GET_BOOT_PARTITION_INFO HECI command 2. Get the me_rw.version from the currently selected RW slot. 3. If the versions from the above 2 locations don't match start the update - If CSE's current boot partition is not RO, then * Set the CSE's next boot partition to RO using SET_BOOT_PARTITION HECI command. * Send global reset command to reset the system. - Enable HMRFPO (Host ME Region Flash Protection Override) operation mode using HMRFPO_ENABLE HECI command - Erase and Copy the CBFS CSE RW to CSE RW partition - Set the CSE's next boot partition to RW using SET_BOOT_PARTITION HECI command - Trigger global reset - The system should boot with the updated CSE RW partition. TEST=Verified basic update flows on hatch and helios. BUG=b:111330995 Change-Id: I12f6bba3324069d65edabaccd234006b0840e700 Signed-off-by: Rizwan Qureshi Signed-off-by: Sridhar Siricilla Signed-off-by: V Sowmya Reviewed-on: https://review.coreboot.org/c/coreboot/+/35403 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh Reviewed-by: Tim Wawrzynczak Reviewed-by: Angel Pons --- .../soc/intel/cse_fw_update/Layout_after.svg | 150 +++++++++++++++++++++ .../soc/intel/cse_fw_update/Layout_before.svg | 95 +++++++++++++ .../soc/intel/cse_fw_update/cse_fw_update.md | 127 +++++++++++++++++ 3 files changed, 372 insertions(+) create mode 100644 Documentation/soc/intel/cse_fw_update/Layout_after.svg create mode 100644 Documentation/soc/intel/cse_fw_update/Layout_before.svg create mode 100644 Documentation/soc/intel/cse_fw_update/cse_fw_update.md (limited to 'Documentation/soc/intel/cse_fw_update') diff --git a/Documentation/soc/intel/cse_fw_update/Layout_after.svg b/Documentation/soc/intel/cse_fw_update/Layout_after.svg new file mode 100644 index 000000000000..95720db6b5a9 --- /dev/null +++ b/Documentation/soc/intel/cse_fw_update/Layout_after.svg @@ -0,0 +1,150 @@ + + + + + + + + + + + + + + + + Page-1 + + Rectangle.116 + DESC + + DESC + + Rectangle.117 + CSE - RO + + CSE - RO + + Rectangle.118 + + + + Rectangle.119 + COREBOOT_RO + + COREBOOT_RO + + Rectangle.120 + RW_MISC + + RW_MISC + + Rectangle.121 + FW_MAIN_B + + FW_MAIN_B + + Rectangle.122 + FW_MAIN_A + + FW_MAIN_A + + Sheet.123 + 0x1FFFFFF + + 0x1FFFFFF + + Sheet.124 + 0x0 + + 0x0 + + Rectangle.125 + RW_LEGACY + + RW_LEGACY + + Right Brace.126 + + + + Sheet.127 + HW WP + + HW WP + + Right Brace.128 + + + + Sheet.129 + SPI Controller WP via descriptor + + SPI Controller WP via descriptor + + Sheet.130 + + Rectangle.423 + CSE-RW + + CSE-RW + + + Sheet.132 + + Rectangle.423 + CSE-RW + + CSE-RW + + + Rectangle.134 + CSE-RW + + CSE-RW + + Universal connector.473 + + + + Universal connector.136 + + + + Sheet.138 + CSE RW copied during an update + + CSE RW copied during an update + + Right Brace.139 + + + + Sheet.140 + GRP0 Protected + + GRP0 Protected + + diff --git a/Documentation/soc/intel/cse_fw_update/Layout_before.svg b/Documentation/soc/intel/cse_fw_update/Layout_before.svg new file mode 100644 index 000000000000..d03754880e61 --- /dev/null +++ b/Documentation/soc/intel/cse_fw_update/Layout_before.svg @@ -0,0 +1,95 @@ + + + + + + + + Page-1 + + Rectangle.178 + DESC + + DESC + + Rectangle.179 + CSME/PMC + + CSME/PMC + + Rectangle.180 + + + + Rectangle.181 + COREBOOT_RO + + COREBOOT_RO + + Rectangle.182 + RW_MISC + + RW_MISC + + Rectangle.183 + FW_MAIN_B + + FW_MAIN_B + + Rectangle.184 + FW_MAIN_A + + FW_MAIN_A + + Sheet.94 + 0x1FFFFFF + + 0x1FFFFFF + + Sheet.95 + 0x0 + + 0x0 + + Rectangle.106 + RW_LEGACY + + RW_LEGACY + + Right Brace.398 + + + + Sheet.96 + HW WP + + HW WP + + Right Brace.115 + + + + Sheet.97 + SPI Controller WP via descriptor + + SPI Controller WP via descriptor + + diff --git a/Documentation/soc/intel/cse_fw_update/cse_fw_update.md b/Documentation/soc/intel/cse_fw_update/cse_fw_update.md new file mode 100644 index 000000000000..98fe31011363 --- /dev/null +++ b/Documentation/soc/intel/cse_fw_update/cse_fw_update.md @@ -0,0 +1,127 @@ +CSE FW update mechanism for devices in field + +## Introduction + +CSE Firmware and PMC Firmware are critical components of Intel SoCs. +CSE and PMC cooperate by providing platform services during boot and other +power transition flows. + +## Problem Statement + +Currently, on Chromium OS Systems, CSE region is not updatable. So, new CSE FW +versions that are released by Intel to address important functional and security +bugs post-product launch will not be available to the end-user. Hence, the proposed +solution allows in-field CSE FW update to propagate those bug fixes +to end user platforms. + +## Design Proposal + +### CSE FW design Proposal: + +Key Elements: + +- CSE FW layout is composed of two bootable partitions (RO Recovery Partition + and RW Normal Partition). + +- Boot partition selection: An API-based mechanism is used to decide from which partition + CSE will boot. + +- The HECI APIs below will be supported in this CSE FW: + + - HMRFPO_ENABLE: This command requests the CSE enter a mode in which writes to + the CSE region from the CSE are disabled. It also grants temporary write access + to the RW partition from the host (RO is still protected by GPR0). + + - GET_PARTITION_INFO: The command retrieves information for each boot partition from CSE + like version, start/end offsets of a partition within CSE region, and boot + partition status. Also, it provides below information: + - The current boot partition which was used during this boot, + - The boot partition that will be used on the next CSE reset + - The number of boot partitions available in the CSE region + + - SET_BOOT_PARTITION_INFO: This command allows the firmware to request the + CSE to boot from either its RO or RW partition at its next reset. + + - DATA_CLEAR: This command requests the CSE to reset its data partition back + to manufacturing defaults + +FW Layout, RW/RO Partitions: + +The CSE RO partition is the first in the CSE boot order, hence it will be used +out of G3. RO partition contains minimum CSE code capable to boot platform and +execute FW update of RW partition. In addition to CSE code, the RO partition also +contains PMC FW patch and other CSE-loadable platform FW components. + +RW partition contains fully operational CSE FW, PMC FW, other CSE loadable +platform FW components. + +Boot partition selection: + +CSE FW shall support 2 APIs to get boot partition info, and set boot partition +info to notify CSE to select the partition on the next boot. + +### HOST FW Design proposal: + +Key Elements: + +- Build time artifacts: + + CSE RW Version update binary - The FW shall pack CSE RW update blob and + corresponding version binary which contains version of the CSE RW blob. + +- FW Update: + + coreboot will implement the logic to compare the CSE's FW version with CBFS + CSE RW binary's version in the firmware slot (FW_MAIN_A/FW_MAIN_B) and update + the CSE RW region if there is a version mismatch. If there is no version + mismatch, firmware skips CSE FW update. + +- Handling of CSE FW Downgrade: + + coreboot will send DATA_CLEAR HECI command when there is a CSE FW downgrade. + This must be done to avoid data mismatch due to CSE FW downgrade. Further, + CSE will restore the data back to manufacturing defaults after data reset. + + +## Implementation Details + + +To enable CSE FW update flow the following changes are required in coreboot: + +* Descriptor change may be required to accommodate CSE binary. The CSE binary is tied with +a platform. So CSE size may vary from one platform to another. +* FMAP changes may be required to accommodate CSE binary and CSE RW blob in the RW CBFS region. +Please check platform specific CSE kit for CSE binary information. +* CSE Lite SKU binary and CSE RW blob +* Makefile change to pack CSE RW binaries in the CBFS +* Implementation of update flow: + - Get CSE boot partition info using GET_BOOT_PARTITION_INFO HECI command. + - Get the cbfs_me_rw.version from the currently selected RW slot. + - If the version from the above 2 locations don't match, then start CSE FW update. + - If CSE is not booting from RO, then + - Set the CSE's next boot partition to RO using SET_BOOT_PARTITION_INFO + HECI command. + - Send GLOBAL_RESET HECI command to reset the system. + - If RW update is a CSE FW downgrade, then coreboot has to send + DATA_CLEAR command to clear run time data of CSE. + - Enable HMRFPO Mode (Host ME Region Flash Protection Override) by + sending HMRFPO_ENABLE HECI command to CSE. + - Erase and Copy the CBFS CSE RW to CSE RW partition + - Set CSE's next boot partition to RW. + - Trigger Global Reset which resets both CSE and Host. + Then system should boot with the updated CSE. + +* The resulting flash layout is shown below: + +![Flash Layout](./Layout_before.svg) ![FlashLayout](./Layout_after.svg) + + + - Typical boot flow + + - Vboot selects the RW FW (FW_MAIN_A or FW_MAIN_B) to boot. + - coreboot skips CSE FW update flow if boot mode is recovery. + - If CSE RW blob is not locatable in the CBFS, then RW Firmware skips update flow + and sends SET_BOOT_PARTITION_INFO command to switch CSE to boot from RW + and issues Global Reset if CSE is already not booting from RW partition. + - The RW firmware will compare the CSE RW version with CSE RW blob in the slot. + - If there is a mismatch, then firmware will carry out update flow as explained before. -- cgit v1.2.3