diff options
Diffstat (limited to 'bl2u/aarch32/bl2u_entrypoint.S')
-rw-r--r-- | bl2u/aarch32/bl2u_entrypoint.S | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/bl2u/aarch32/bl2u_entrypoint.S b/bl2u/aarch32/bl2u_entrypoint.S new file mode 100644 index 0000000..1063789 --- /dev/null +++ b/bl2u/aarch32/bl2u_entrypoint.S @@ -0,0 +1,127 @@ +/* + * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch.h> +#include <asm_macros.S> +#include <common/bl_common.h> + + .globl bl2u_vector_table + .globl bl2u_entrypoint + + +vector_base bl2u_vector_table + b bl2u_entrypoint + b report_exception /* Undef */ + b report_exception /* SVC call */ + b report_prefetch_abort /* Prefetch abort */ + b report_data_abort /* Data abort */ + b report_exception /* Reserved */ + b report_exception /* IRQ */ + b report_exception /* FIQ */ + + +func bl2u_entrypoint + /*--------------------------------------------- + * Save from r1 the extents of the trusted ram + * available to BL2U for future use. + * r0 is not currently used. + * --------------------------------------------- + */ + mov r11, r1 + mov r10, r2 + + /* --------------------------------------------- + * Set the exception vector to something sane. + * --------------------------------------------- + */ + ldr r0, =bl2u_vector_table + stcopr r0, VBAR + isb + + /* -------------------------------------------------------- + * Enable the instruction cache - disable speculative loads + * -------------------------------------------------------- + */ + ldcopr r0, SCTLR + orr r0, r0, #SCTLR_I_BIT + bic r0, r0, #SCTLR_DSSBS_BIT + stcopr r0, SCTLR + isb + + /* --------------------------------------------- + * Since BL2U executes after BL1, it is assumed + * here that BL1 has already has done the + * necessary register initializations. + * --------------------------------------------- + */ + + /* --------------------------------------------- + * Invalidate the RW memory used by the BL2U + * image. This includes the data and NOBITS + * sections. This is done to safeguard against + * possible corruption of this memory by dirty + * cache lines in a system cache as a result of + * use by an earlier boot loader stage. + * --------------------------------------------- + */ + ldr r0, =__RW_START__ + ldr r1, =__RW_END__ + sub r1, r1, r0 + bl inv_dcache_range + + /* --------------------------------------------- + * Zero out NOBITS sections. There are 2 of them: + * - the .bss section; + * - the coherent memory section. + * --------------------------------------------- + */ + ldr r0, =__BSS_START__ + ldr r1, =__BSS_END__ + sub r1, r1, r0 + bl zeromem + + /* -------------------------------------------- + * Allocate a stack whose memory will be marked + * as Normal-IS-WBWA when the MMU is enabled. + * There is no risk of reading stale stack + * memory after enabling the MMU as only the + * primary cpu is running at the moment. + * -------------------------------------------- + */ + bl plat_set_my_stack + + /* --------------------------------------------- + * Initialize the stack protector canary before + * any C code is called. + * --------------------------------------------- + */ +#if STACK_PROTECTOR_ENABLED + bl update_stack_protector_canary +#endif + + /* --------------------------------------------- + * Perform early platform setup & platform + * specific early arch. setup e.g. mmu setup + * --------------------------------------------- + */ + mov r0, r11 + mov r1, r10 + bl bl2u_early_platform_setup + bl bl2u_plat_arch_setup + + /* --------------------------------------------- + * Jump to main function. + * --------------------------------------------- + */ + bl bl2u_main + + /* --------------------------------------------- + * Should never reach this point. + * --------------------------------------------- + */ + no_ret plat_panic_handler + +endfunc bl2u_entrypoint |