diff options
Diffstat (limited to 'plat/arm/css/drivers/scp/css_bom_bootloader.c')
| -rw-r--r-- | plat/arm/css/drivers/scp/css_bom_bootloader.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/plat/arm/css/drivers/scp/css_bom_bootloader.c b/plat/arm/css/drivers/scp/css_bom_bootloader.c new file mode 100644 index 00000000..a92ce6b4 --- /dev/null +++ b/plat/arm/css/drivers/scp/css_bom_bootloader.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch_helpers.h> +#include <assert.h> +#include <css_def.h> +#include <debug.h> +#include <platform.h> +#include <stdint.h> +#include "../scpi/css_mhu.h" +#include "../scpi/css_scpi.h" + +/* ID of the MHU slot used for the BOM protocol */ +#define BOM_MHU_SLOT_ID 0 + +/* Boot commands sent from AP -> SCP */ +#define BOOT_CMD_INFO 0x00 +#define BOOT_CMD_DATA 0x01 + +/* BOM command header */ +typedef struct { + uint32_t id : 8; + uint32_t reserved : 24; +} bom_cmd_t; + +typedef struct { + uint32_t image_size; + uint32_t checksum; +} cmd_info_payload_t; + +/* + * Unlike the SCPI protocol, the boot protocol uses the same memory region + * for both AP -> SCP and SCP -> AP transfers; define the address of this... + */ +#define BOM_SHARED_MEM PLAT_CSS_SCP_COM_SHARED_MEM_BASE +#define BOM_CMD_HEADER ((bom_cmd_t *) BOM_SHARED_MEM) +#define BOM_CMD_PAYLOAD ((void *) (BOM_SHARED_MEM + sizeof(bom_cmd_t))) + +typedef struct { + /* Offset from the base address of the Trusted RAM */ + uint32_t offset; + uint32_t block_size; +} cmd_data_payload_t; + +/* + * All CSS platforms load SCP_BL2/SCP_BL2U just below BL rw-data and above + * BL2/BL2U (this is where BL31 usually resides except when ARM_BL31_IN_DRAM is + * set. Ensure that SCP_BL2/SCP_BL2U do not overflow into BL1 rw-data nor + * BL2/BL2U. + */ +CASSERT(SCP_BL2_LIMIT <= BL1_RW_BASE, assert_scp_bl2_overwrite_bl1); +CASSERT(SCP_BL2U_LIMIT <= BL1_RW_BASE, assert_scp_bl2u_overwrite_bl1); + +CASSERT(SCP_BL2_BASE >= BL2_LIMIT, assert_scp_bl2_overwrite_bl2); +CASSERT(SCP_BL2U_BASE >= BL2U_LIMIT, assert_scp_bl2u_overwrite_bl2u); + +static void scp_boot_message_start(void) +{ + mhu_secure_message_start(BOM_MHU_SLOT_ID); +} + +static void scp_boot_message_send(size_t payload_size) +{ + /* Ensure that any write to the BOM payload area is seen by SCP before + * we write to the MHU register. If these 2 writes were reordered by + * the CPU then SCP would read stale payload data */ + dmbst(); + + /* Send command to SCP */ + mhu_secure_message_send(BOM_MHU_SLOT_ID); +} + +static uint32_t scp_boot_message_wait(size_t size) +{ + uint32_t mhu_status; + + mhu_status = mhu_secure_message_wait(); + + /* Expect an SCP Boot Protocol message, reject any other protocol */ + if (mhu_status != (1 << BOM_MHU_SLOT_ID)) { + ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n", + mhu_status); + panic(); + } + + /* Ensure that any read to the BOM payload area is done after reading + * the MHU register. If these 2 reads were reordered then the CPU would + * read invalid payload data */ + dmbld(); + + return *(uint32_t *) BOM_SHARED_MEM; +} + +static void scp_boot_message_end(void) +{ + mhu_secure_message_end(BOM_MHU_SLOT_ID); +} + +int css_scp_boot_image_xfer(void *image, unsigned int image_size) +{ + uint32_t response; + uint32_t checksum; + cmd_info_payload_t *cmd_info_payload; + cmd_data_payload_t *cmd_data_payload; + + assert((uintptr_t) image == SCP_BL2_BASE); + + if ((image_size == 0) || (image_size % 4 != 0)) { + ERROR("Invalid size for the SCP_BL2 image. Must be a multiple of " + "4 bytes and not zero (current size = 0x%x)\n", + image_size); + return -1; + } + + /* Extract the checksum from the image */ + checksum = *(uint32_t *) image; + image = (char *) image + sizeof(checksum); + image_size -= sizeof(checksum); + + mhu_secure_init(); + + VERBOSE("Send info about the SCP_BL2 image to be transferred to SCP\n"); + + /* + * Send information about the SCP firmware image about to be transferred + * to SCP + */ + scp_boot_message_start(); + + BOM_CMD_HEADER->id = BOOT_CMD_INFO; + cmd_info_payload = BOM_CMD_PAYLOAD; + cmd_info_payload->image_size = image_size; + cmd_info_payload->checksum = checksum; + + scp_boot_message_send(sizeof(*cmd_info_payload)); +#if CSS_DETECT_PRE_1_7_0_SCP + { + const uint32_t deprecated_scp_nack_cmd = 0x404; + uint32_t mhu_status; + + VERBOSE("Detecting SCP version incompatibility\n"); + + mhu_status = mhu_secure_message_wait(); + if (mhu_status == deprecated_scp_nack_cmd) { + ERROR("Detected an incompatible version of the SCP firmware.\n"); + ERROR("Only versions from v1.7.0 onwards are supported.\n"); + ERROR("Please update the SCP firmware.\n"); + return -1; + } + + VERBOSE("SCP version looks OK\n"); + } +#endif /* CSS_DETECT_PRE_1_7_0_SCP */ + response = scp_boot_message_wait(sizeof(response)); + scp_boot_message_end(); + + if (response != 0) { + ERROR("SCP BOOT_CMD_INFO returned error %u\n", response); + return -1; + } + + VERBOSE("Transferring SCP_BL2 image to SCP\n"); + + /* Transfer SCP_BL2 image to SCP */ + scp_boot_message_start(); + + BOM_CMD_HEADER->id = BOOT_CMD_DATA; + cmd_data_payload = BOM_CMD_PAYLOAD; + cmd_data_payload->offset = (uintptr_t) image - ARM_TRUSTED_SRAM_BASE; + cmd_data_payload->block_size = image_size; + + scp_boot_message_send(sizeof(*cmd_data_payload)); + response = scp_boot_message_wait(sizeof(response)); + scp_boot_message_end(); + + if (response != 0) { + ERROR("SCP BOOT_CMD_DATA returned error %u\n", response); + return -1; + } + + return 0; +} + +int css_scp_boot_ready(void) +{ + VERBOSE("Waiting for SCP to signal it is ready to go on\n"); + + /* Wait for SCP to signal it's ready */ + return scpi_wait_ready(); +} |