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