1 /* 2 * Copyright 2017 Theobroma Systems Design und Consulting GmbH 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 /* 8 * Execution starts on the instruction following this 4-byte header 9 * (containing the magic 'RK30', 'RK31', 'RK32' or 'RK33'). This 10 * magic constant will be written into the final image by the rkimage 11 * tool, but we need to reserve space for it here. 12 * 13 * To make life easier for everyone, we build the SPL binary with 14 * space for this 4-byte header already included in the binary. 15 */ 16 #ifdef CONFIG_SPL_BUILD 17 /* 18 * We need to add 4 bytes of space for the 'RK33' at the 19 * beginning of the executable. However, as we want to keep 20 * this generic and make it applicable to builds that are like 21 * the RK3368 (TPL needs this, SPL doesn't) or the RK3399 (no 22 * TPL, but extra space needed in the SPL), we simply insert 23 * a branch-to-next-instruction-word with the expectation that 24 * the first one may be overwritten, if this is the first stage 25 * contained in the final image created with mkimage)... 26 */ 27 b 1f /* if overwritten, entry-address is at the next word */ 28 1: 29 #endif 30 #if CONFIG_IS_ENABLED(ROCKCHIP_EARLYRETURN_TO_BROM) 31 adr r3, entry_counter 32 ldr r0, [r3] 33 cmp r0, #1 /* check if entry_counter == 1 */ 34 beq reset /* regular bootup */ 35 add r0, #1 36 str r0, [r3] /* increment the entry_counter in memory */ 37 mov r0, #0 /* return 0 to the BROM to signal 'OK' */ 38 bx lr /* return control to the BROM */ 39 entry_counter: 40 .word 0 41 #endif 42 43 #if (defined(CONFIG_SPL_BUILD) || defined(CONFIG_ARM64)) 44 /* U-Boot proper of armv7 do not need this */ 45 b reset 46 #endif 47 48 #if !defined(CONFIG_ARM64) 49 /* 50 * For armv7, the addr '_start' will used as vector start address 51 * and write to VBAR register, which needs to aligned to 0x20. 52 */ 53 .align(5), 0x0 54 _start: 55 ARM_VECTORS 56 #endif 57 58 #if defined(CONFIG_SPL_BUILD) && (CONFIG_ROCKCHIP_SPL_RESERVE_IRAM > 0) 59 .space CONFIG_ROCKCHIP_SPL_RESERVE_IRAM /* space for the ATF data */ 60 #endif 61