1 /** 2 * Copyright (c) 2017 Google, Inc 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <asm/arch/bootrom.h> 9 #include <asm/setjmp.h> 10 #include <asm/system.h> 11 12 /* 13 * Force the jmp_buf to the data-section, as .bss will not be valid 14 * when save_boot_params is invoked. 15 */ 16 static jmp_buf brom_ctx __section(".data"); 17 18 void back_to_bootrom(void) 19 { 20 #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) 21 puts("Returning to boot ROM...\n"); 22 #endif 23 longjmp(brom_ctx, BROM_BOOT_NEXTSTAGE); 24 } 25 26 /* 27 * All Rockchip BROM implementations enter with a valid stack-pointer, 28 * so this can safely be implemented in C (providing a single 29 * implementation both for ARMv7 and AArch64). 30 */ 31 int save_boot_params(void) 32 { 33 int ret = setjmp(brom_ctx); 34 35 switch (ret) { 36 case 0: 37 /* 38 * This is the initial pass through this function 39 * (i.e. saving the context), setjmp just setup up the 40 * brom_ctx: transfer back into the startup-code at 41 * 'save_boot_params_ret' and let the compiler know 42 * that this will not return. 43 */ 44 save_boot_params_ret(); 45 while (true) 46 /* does not return */; 47 break; 48 49 case BROM_BOOT_NEXTSTAGE: 50 /* 51 * To instruct the BROM to boot the next stage, we 52 * need to return 0 to it: i.e. we need to rewrite 53 * the return code once more. 54 */ 55 ret = 0; 56 break; 57 58 default: 59 #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) 60 puts("FATAL: unexpected command to back_to_bootrom()\n"); 61 #endif 62 hang(); 63 }; 64 65 return ret; 66 } 67