* Andrew F. Davis <afd@xxxxxx> [170314 10:59]: > On 03/14/2017 11:41 AM, Tony Lindgren wrote: > > * Andrew F. Davis <afd@xxxxxx> [170314 09:04]: > >> On 03/14/2017 10:17 AM, Tony Lindgren wrote: > >>> And if the CPU1 start-up address is programmed to be in the currently > >>> booting kernel's area by something else, it's almost certainly totally > >>> broken. > >>> > >> > >> I disagree, the core can be parked correctly and still have the boot-to > >> address point to anywhere. There are two registers in play here, one > >> sets the target jump-to address, the other lets it out of the parking > >> loop. To know we are not parked we need to check the parking release > >> register, the jump-to address is completely irrelevant as a check for > >> proper parking. > > > > Well at this point we have CPU1 parked and configured for a wrong > > start-up address. So the boot-to address is a valid check. I can > > certainly add a check for CPU1 being parked too. OK I sent out v3 version of the patch doing that. Can you please review and test that one? <snip> Then onto the other related patches.. > We re-park cpu1 in bootROM in U-Boot already, in the U-Boot tree: > arch/arm/mach-omap2/omap5/sec_entry_cpu1.S OK good to hear. > omap_smc_sec_cpu1() wakes up cpu1 into the function cpu1_entry(), this > makes an SMC call to setup the core, then re-parks itself back in bootROM. > Relevant code to run on cpu1: > > > #define AUX_CORE_BOOT_0 0x48281800 > > #define AUX_CORE_BOOT_1 0x48281804 > > /* DRA7xx ROM code function "startup_BootSlave". This function is where CPU1 > > * waits on WFE, polling on AUX_CORE_BOOT_x registers. > > * This address is same for J6 and J6 Eco. > > */ > > #define ROM_FXN_STARTUP_BOOTSLAVE 0x00038a64 > > > > ldr r4, =AUX_CORE_BOOT_0 > > mov r5, #0x0 > > str r5, [r4] > > ldr r4, =ROM_FXN_STARTUP_BOOTSLAVE > > bx r4 @ Jump back to ROM > > We would have to do this in kernel. The issue I'm thinking we are going > to hit is that the parking function in bootROM expects the MMU to be > off. Although we don't really need to turn it off as long as we can > identity map the bootROM area, the AUX_CORE_BOOT_0/1 space, and wherever > we plan to exit the parking loop. Would be good to hear what Russell thinks we should do here to park CPU1. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
