/* * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of ARM nor the names of its contributors may be used * to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include /*********************************************************** * Memory for sharing data while changing exception levels. * Only used by the primary core. **********************************************************/ unsigned char bl2_el_change_mem_ptr[EL_CHANGE_MEM_SIZE]; unsigned long *get_el_change_mem_ptr(void) { return (unsigned long *) bl2_el_change_mem_ptr; } unsigned long page_align(unsigned long value, unsigned dir) { unsigned long page_size = 1 << FOUR_KB_SHIFT; /* Round up the limit to the next page boundary */ if (value & (page_size - 1)) { value &= ~(page_size - 1); if (dir == UP) value += page_size; } return value; } static inline unsigned int is_page_aligned (unsigned long addr) { const unsigned long page_size = 1 << FOUR_KB_SHIFT; return (addr & (page_size - 1)) == 0; } void change_security_state(unsigned int target_security_state) { unsigned long scr = read_scr(); if (target_security_state == SECURE) scr &= ~SCR_NS_BIT; else if (target_security_state == NON_SECURE) scr |= SCR_NS_BIT; else assert(0); write_scr(scr); } int drop_el(aapcs64_params *args, unsigned long spsr, unsigned long entrypoint) { write_spsr(spsr); write_elr(entrypoint); eret(args->arg0, args->arg1, args->arg2, args->arg3, args->arg4, args->arg5, args->arg6, args->arg7); return -EINVAL; } long raise_el(aapcs64_params *args) { return smc(args->arg0, args->arg1, args->arg2, args->arg3, args->arg4, args->arg5, args->arg6, args->arg7); } /* * TODO: If we are not EL3 then currently we only issue an SMC. * Add support for dropping into EL0 etc. Consider adding support * for switching from S-EL1 to S-EL0/1 etc. */ long change_el(el_change_info *info) { unsigned long current_el = read_current_el(); if (GET_EL(current_el) == MODE_EL3) { /* * We can go anywhere from EL3. So find where. * TODO: Lots to do if we are going non-secure. * Flip the NS bit. Restore NS registers etc. * Just doing the bare minimal for now. */ if (info->security_state == NON_SECURE) change_security_state(info->security_state); return drop_el(&info->args, info->spsr, info->entrypoint); } else return raise_el(&info->args); } /* TODO: add a parameter for DAIF. not needed right now */ unsigned long make_spsr(unsigned long target_el, unsigned long target_sp, unsigned long target_rw) { unsigned long spsr; /* Disable all exceptions & setup the EL */ spsr = (DAIF_FIQ_BIT | DAIF_IRQ_BIT | DAIF_ABT_BIT | DAIF_DBG_BIT) << PSR_DAIF_SHIFT; spsr |= PSR_MODE(target_rw, target_el, target_sp); return spsr; } /******************************************************************************* * The next two functions are the weak definitions. Platform specific * code can override them if it wishes to. ******************************************************************************/ /******************************************************************************* * Function that takes a memory layout into which BL31 has been either top or * bottom loaded. Using this information, it populates bl31_mem_layout to tell * BL31 how much memory it has access to and how much is available for use. It * does not need the address where BL31 has been loaded as BL31 will reclaim * all the memory used by BL2. * TODO: Revisit if this and init_bl2_mem_layout can be replaced by a single * routine. ******************************************************************************/ void init_bl31_mem_layout(const meminfo *bl2_mem_layout, meminfo *bl31_mem_layout, unsigned int load_type) { if (load_type == BOT_LOAD) { /* * ------------ ^ * | BL2 | | * |----------| ^ | BL2 * | | | BL2 free | total * | | | size | size * |----------| BL2 free base v | * | BL31 | | * ------------ BL2 total base v */ unsigned long bl31_size; bl31_mem_layout->free_base = bl2_mem_layout->free_base; bl31_size = bl2_mem_layout->free_base - bl2_mem_layout->total_base; bl31_mem_layout->free_size = bl2_mem_layout->total_size - bl31_size; } else { /* * ------------ ^ * | BL31 | | * |----------| ^ | BL2 * | | | BL2 free | total * | | | size | size * |----------| BL2 free base v | * | BL2 | | * ------------ BL2 total base v */ unsigned long bl2_size; bl31_mem_layout->free_base = bl2_mem_layout->total_base; bl2_size = bl2_mem_layout->free_base - bl2_mem_layout->total_base; bl31_mem_layout->free_size = bl2_mem_layout->free_size + bl2_size; } bl31_mem_layout->total_base = bl2_mem_layout->total_base; bl31_mem_layout->total_size = bl2_mem_layout->total_size; bl31_mem_layout->attr = load_type; flush_dcache_range((unsigned long) bl31_mem_layout, sizeof(meminfo)); return; } /******************************************************************************* * Function that takes a memory layout into which BL2 has been either top or * bottom loaded along with the address where BL2 has been loaded in it. Using * this information, it populates bl2_mem_layout to tell BL2 how much memory * it has access to and how much is available for use. ******************************************************************************/ void init_bl2_mem_layout(meminfo *bl1_mem_layout, meminfo *bl2_mem_layout, unsigned int load_type, unsigned long bl2_base) { unsigned tmp; if (load_type == BOT_LOAD) { bl2_mem_layout->total_base = bl2_base; tmp = bl1_mem_layout->free_base - bl2_base; bl2_mem_layout->total_size = bl1_mem_layout->free_size + tmp; } else { bl2_mem_layout->total_base = bl1_mem_layout->free_base; tmp = bl1_mem_layout->total_base + bl1_mem_layout->total_size; bl2_mem_layout->total_size = tmp - bl1_mem_layout->free_base; } bl2_mem_layout->free_base = bl1_mem_layout->free_base; bl2_mem_layout->free_size = bl1_mem_layout->free_size; bl2_mem_layout->attr = load_type; flush_dcache_range((unsigned long) bl2_mem_layout, sizeof(meminfo)); return; } static void dump_load_info(unsigned long image_load_addr, unsigned long image_size, const meminfo *mem_layout) { #if DEBUG printf("Trying to load image at address 0x%lx, size = 0x%lx\r\n", image_load_addr, image_size); printf("Current memory layout:\r\n"); printf(" total region = [0x%lx, 0x%lx]\r\n", mem_layout->total_base, mem_layout->total_base + mem_layout->total_size); printf(" free region = [0x%lx, 0x%lx]\r\n", mem_layout->free_base, mem_layout->free_base + mem_layout->free_size); #endif } /******************************************************************************* * Generic function to load an image into the trusted RAM using semihosting * given a name, extents of free memory & whether the image should be loaded at * the bottom or top of the free memory. It updates the memory layout if the * load is successful. ******************************************************************************/ unsigned long load_image(meminfo *mem_layout, const char *image_name, unsigned int load_type, unsigned long fixed_addr) { unsigned long temp_image_base = 0; unsigned long image_base = 0; long offset = 0; int image_flen; /* Find the size of the image */ image_flen = semihosting_get_flen(image_name); if (image_flen < 0) { printf("ERROR: Cannot access '%s' file (%i).\r\n", image_name, image_flen); return 0; } /* See if we have enough space */ if (image_flen > mem_layout->free_size) { printf("ERROR: Cannot load '%s' file: Not enough space.\r\n", image_name); dump_load_info(0, image_flen, mem_layout); return 0; } switch (load_type) { case TOP_LOAD: /* Load the image in the top of free memory */ temp_image_base = mem_layout->free_base + mem_layout->free_size; temp_image_base -= image_flen; /* Page align base address and check whether the image still fits */ image_base = page_align(temp_image_base, DOWN); assert(image_base <= temp_image_base); if (image_base < mem_layout->free_base) { printf("ERROR: Cannot load '%s' file: Not enough space.\r\n", image_name); dump_load_info(image_base, image_flen, mem_layout); return 0; } /* Calculate the amount of extra memory used due to alignment */ offset = temp_image_base - image_base; break; case BOT_LOAD: /* Load the BL2 image in the bottom of free memory */ temp_image_base = mem_layout->free_base; image_base = page_align(temp_image_base, UP); assert(image_base >= temp_image_base); /* Page align base address and check whether the image still fits */ if (image_base + image_flen > mem_layout->free_base + mem_layout->free_size) { printf("ERROR: Cannot load '%s' file: Not enough space.\r\n", image_name); dump_load_info(image_base, image_flen, mem_layout); return 0; } /* Calculate the amount of extra memory used due to alignment */ offset = image_base - temp_image_base; break; default: assert(0); } /* * Some images must be loaded at a fixed address, not a dynamic one. * * This has been implemented as a hack on top of the existing dynamic * loading mechanism, for the time being. If the 'fixed_addr' function * argument is different from zero, then it will force the load address. * So we still have this principle of top/bottom loading but the code * determining the load address is bypassed and the load address is * forced to the fixed one. * * This can result in quite a lot of wasted space because we still use * 1 sole meminfo structure to represent the extents of free memory, * where we should use some sort of linked list. * * E.g. we want to load BL2 at address 0x04020000, the resulting memory * layout should look as follows: * ------------ 0x04040000 * | | <- Free space (1) * |----------| * | BL2 | * |----------| 0x04020000 * | | <- Free space (2) * |----------| * | BL1 | * ------------ 0x04000000 * * But in the current hacky implementation, we'll need to specify * whether BL2 is loaded at the top or bottom of the free memory. * E.g. if BL2 is considered as top-loaded, the meminfo structure * will give the following view of the memory, hiding the chunk of * free memory above BL2: * ------------ 0x04040000 * | | * | | * | BL2 | * |----------| 0x04020000 * | | <- Free space (2) * |----------| * | BL1 | * ------------ 0x04000000 */ if (fixed_addr != 0) { /* Load the image at the given address. */ image_base = fixed_addr; /* Check whether the image fits. */ if ((image_base < mem_layout->free_base) || (image_base + image_flen > mem_layout->free_base + mem_layout->free_size)) { printf("ERROR: Cannot load '%s' file: Not enough space.\r\n", image_name); dump_load_info(image_base, image_flen, mem_layout); return 0; } /* Check whether the fixed load address is page-aligned. */ if (!is_page_aligned(image_base)) { printf("ERROR: Cannot load '%s' file at unaligned address 0x%lx.\r\n", image_name, fixed_addr); return 0; } /* * Calculate the amount of extra memory used due to fixed * loading. */ if (load_type == TOP_LOAD) { unsigned long max_addr, space_used; /* * ------------ max_addr * | /wasted/ | | offset * |..........|.............................. * | image | | image_flen * |----------| fixed_addr * | | * | | * ------------ total_base */ max_addr = mem_layout->total_base + mem_layout->total_size; /* * Compute the amount of memory used by the image. * Corresponds to all space above the image load * address. */ space_used = max_addr - fixed_addr; /* * Calculate the amount of wasted memory within the * amount of memory used by the image. */ offset = space_used - image_flen; } else /* BOT_LOAD */ /* * ------------ * | | * | | * |----------| * | image | * |..........| fixed_addr * | /wasted/ | | offset * ------------ total_base */ offset = fixed_addr - mem_layout->total_base; } /* We have enough space so load the image now */ image_flen = semihosting_download_file(image_name, image_flen, (void *) image_base); if (image_flen <= 0) { printf("ERROR: Failed to load '%s' file from semihosting (%i).\r\n", image_name, image_flen); return 0; } /* * File has been successfully loaded. Update the free memory * data structure & flush the contents of the TZRAM so that * the next EL can see it. */ /* Update the memory contents */ flush_dcache_range(image_base, image_flen); mem_layout->free_size -= image_flen + offset; /* Update the base of free memory since its moved up */ if (load_type == BOT_LOAD) mem_layout->free_base += offset + image_flen; return image_base; } /******************************************************************************* * Run a loaded image from the given entry point. This could result in either * dropping into a lower exception level or jumping to a higher exception level. * The only way of doing the latter is through an SMC. In either case, setup the * parameters for the EL change request correctly. ******************************************************************************/ int run_image(unsigned long entrypoint, unsigned long spsr, unsigned long target_security_state, meminfo *mem_layout, void *data) { el_change_info run_image_info; unsigned long current_el = read_current_el(); /* Tell next EL what we want done */ run_image_info.args.arg0 = RUN_IMAGE; run_image_info.entrypoint = entrypoint; run_image_info.spsr = spsr; run_image_info.security_state = target_security_state; run_image_info.next = 0; /* * If we are EL3 then only an eret can take us to the desired * exception level. Else for the time being assume that we have * to jump to a higher EL and issue an SMC. Contents of argY * will go into the general purpose register xY e.g. arg0->x0 */ if (GET_EL(current_el) == MODE_EL3) { run_image_info.args.arg1 = (unsigned long) mem_layout; run_image_info.args.arg2 = (unsigned long) data; } else { run_image_info.args.arg1 = entrypoint; run_image_info.args.arg2 = spsr; run_image_info.args.arg3 = (unsigned long) mem_layout; run_image_info.args.arg4 = (unsigned long) data; } return change_el(&run_image_info); }