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