From cc47e1ada6d9a4234d8ca6547008ddc10e6e6568 Mon Sep 17 00:00:00 2001 From: Dimitris Papastamos Date: Wed, 14 Jun 2017 14:47:36 +0100 Subject: [PATCH] juno/aarch32: Restore `SCP_BOOT_CFG_ADDR` to the cold boot value Before BL2 loads the SCP ram firmware, `SCP_BOOT_CFG_ADDR` specifies the primary core. After the SCP ram firmware has started executing, `SCP_BOOT_CFG_ADDR` is modified. This is not normally an issue but the Juno AArch32 boot flow is a special case. BL1 does a warm reset into AArch32 and the core jumps to the `sp_min` entrypoint. This is effectively a `RESET_TO_SP_MIN` configuration. `sp_min` has to be able to determine the primary core and hence we need to restore `SCP_BOOT_CFG_ADDR` to the cold boot value before `sp_min` runs. This magically worked when booting on A53 because the core index was zero and it just so happened to match with the new value in `SCP_BOOT_CFG_ADDR`. Change-Id: I105425c680cf6238948625c1d1017b01d3517c01 Signed-off-by: Dimitris Papastamos --- plat/arm/board/juno/juno_bl2_setup.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/plat/arm/board/juno/juno_bl2_setup.c b/plat/arm/board/juno/juno_bl2_setup.c index 8f18531a1..abceb0f5e 100644 --- a/plat/arm/board/juno/juno_bl2_setup.c +++ b/plat/arm/board/juno/juno_bl2_setup.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -29,4 +29,28 @@ int bl2_plat_handle_post_image_load(unsigned int image_id) return err; } + +/* + * We need to override some of the platform functions when booting SP_MIN + * on Juno AArch32. + */ + +static unsigned int scp_boot_config; + +void bl2_early_platform_setup(meminfo_t *mem_layout) +{ + arm_bl2_early_platform_setup(mem_layout); + + /* Save SCP Boot config before it gets overwritten by SCP_BL2 loading */ + VERBOSE("BL2: Saving SCP Boot config = 0x%x\n", scp_boot_config); + scp_boot_config = mmio_read_32(SCP_BOOT_CFG_ADDR); +} + +void bl2_platform_setup(void) +{ + arm_bl2_platform_setup(); + + mmio_write_32(SCP_BOOT_CFG_ADDR, scp_boot_config); + VERBOSE("BL2: Restored SCP Boot config = 0x%x\n", scp_boot_config); +} #endif /* JUNO_AARCH32_EL3_RUNTIME */