diff --git a/doc/README.srio-boot-corenet b/doc/README.srio-boot-corenet new file mode 100644 index 0000000000000000000000000000000000000000..56b094c9a27db4289d6444784025706b6bbd783b --- /dev/null +++ b/doc/README.srio-boot-corenet @@ -0,0 +1,103 @@ +------------------------------ +SRIO Boot on Corenet Platforms +------------------------------ + +For some PowerPC processors with SRIO interface, boot location can be configured +to SRIO by RCW. The processor booting from SRIO can do without flash for u-boot +image, ucode and ENV. All the images can be fetched from another processor's +memory space by SRIO link connected between them. + +This document describes the processes based on an example implemented on P4080DS +platforms and a RCW example with boot from SRIO configuration. + +Environment of the SRIO boot: + a) Master and slave can be SOCs in one board or SOCs in separate boards. + b) They are connected with SRIO links, whether 1x or 4x, and directly or + through switch system. + c) Only Master has NorFlash for booting, and all the Master's and Slave's + U-Boot images, UCodes will be stored in this flash. + d) Slave has its own EEPROM for RCW and PBI. + e) Slave's RCW should configure the SerDes for SRIO boot port, set the boot + location to SRIO, and holdoff all the cores if needed. + + ---------- ----------- ----------- + | | | | | | + | | | | | | + | NorFlash|<----->| Master | SRIO | Slave |<---->[EEPROM] + | | | |<===========>| | + | | | | | | + ---------- ----------- ----------- + +The example based on P4080DS platform: + Two P4080DS platforms can be used to implement the boot from SRIO. Their SRIO + ports 0 will be connected directly and will be used for the boot from SRIO. + + 1. Slave's RCW example for boot from SRIO port 0 and core 0 not in holdoff. + 00000000: aa55 aa55 010e 0100 0c58 0000 0000 0000 + 00000010: 1818 1818 0000 8888 7440 4000 0000 2000 + 00000020: f400 0000 0100 0000 0000 0000 0000 0000 + 00000030: 0000 0000 0083 0000 0000 0000 0000 0000 + 00000040: 0000 0000 0000 0000 0813 8040 698b 93fe + + 2. Slave's RCW example for boot from SRIO port 0 and all cores in holdoff. + 00000000: aa55 aa55 010e 0100 0c58 0000 0000 0000 + 00000010: 1818 1818 0000 8888 7440 4000 0000 2000 + 00000020: f440 0000 0100 0000 0000 0000 0000 0000 + 00000030: 0000 0000 0083 0000 0000 0000 0000 0000 + 00000040: 0000 0000 0000 0000 0813 8040 063c 778f + + 3. Sequence in Step by Step. + a) Update RCW for slave with boot from SRIO port 0 configuration. + b) Program slave's U-Boot image, UCode, and ENV parameters into master's + NorFlash. + c) Start up master and it will boot up normally from its NorFlash. + Then, it will finish necessary configurations for slave's boot from + SRIO port 0. + d) Master will set inbound SRIO windows covered slave's U-Boot image stored + in master's NorFlash. + e) Master will set an inbound SRIO window covered slave's UCode stored in + master's NorFlash. + f) Master will set an inbound SRIO window covered slave's ENV stored in + master's NorFlash. + g) If need to release slave's core, master will set outbound SRIO windows + in order to configure slave's registers for the core's releasing. + h) If all cores of slave in holdoff, slave should be powered on before all + the above master's steps, and wait to be released by master. If not all + cores in holdoff, that means core 0 will start up normally, slave should + be powered on after all the above master's steps. In the startup phase + of the slave from SRIO, it will finish some necessary configurations. + i) Slave will set a specific TLB entry for the boot process. + j) Slave will set a LAW entry with the TargetID SRIO port 0 for the boot. + k) Slave will set a specific TLB entry in order to fetch UCode and ENV + from master. + l) Slave will set a LAW entry with the TargetID SRIO port 0 for UCode and ENV. + +How to use this feature: + To use this feature, you need to focus three points. + + 1. Slave's RCW with SRIO boot configurations, and all cores in holdoff + configurations if needed. + Please refer to the examples given above. + + 2. U-Boot image's compilation. + For master, U-Boot image should be generated specifically by + + make xxxx_SRIOBOOT_MASTER_config. + + For example, master U-Boot image used on P4080DS should be compiled with + + make P4080DS_SRIOBOOT_MASTER_config. + + For slave, U-Boot image should be generated specifically by + + make xxxx_SRIOBOOT_SLAVE_config. + + For example, slave U-Boot image used on P4080DS should be compiled with + + make P4080DS_SRIOBOOT_SLAVE_config. + + 3. Necessary modifications based on a specific environment. + For a specific environment, the SRIO port for boot, the addresses of the + slave's U-Boot image, UCode, ENV stored in master's NorFlash, and any other + configurations can be modified in the file: + include/configs/corenet_ds.h.