1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * crt0_s.S: Entry function for SPU-side context save.
4 *
5 * Copyright (C) 2005 IBM
6 *
7 * Entry function for SPU-side of the context save sequence.
8 * Saves all 128 GPRs, sets up an initial stack frame, then
9 * branches to 'main'.
10 */
11
12#include <asm/spu_csa.h>
13
14.data
15.align 7
16.globl regs_spill
17regs_spill:
18.space SIZEOF_SPU_SPILL_REGS, 0x0
19
20.text
21.global _start
22_start:
23	/* SPU Context Save Step 1: Save the first 16 GPRs. */
24	stqa $0, regs_spill + 0
25	stqa $1, regs_spill + 16
26	stqa $2, regs_spill + 32
27	stqa $3, regs_spill + 48
28	stqa $4, regs_spill + 64
29	stqa $5, regs_spill + 80
30	stqa $6, regs_spill + 96
31	stqa $7, regs_spill + 112
32	stqa $8, regs_spill + 128
33	stqa $9, regs_spill + 144
34	stqa $10, regs_spill + 160
35	stqa $11, regs_spill + 176
36	stqa $12, regs_spill + 192
37	stqa $13, regs_spill + 208
38	stqa $14, regs_spill + 224
39	stqa $15, regs_spill + 240
40
41	/* SPU Context Save, Step 8: Save the remaining 112 GPRs. */
42	ila     $3, regs_spill + 256
43save_regs:
44	lqr     $4, save_reg_insts
45save_reg_loop:
46	ai      $4, $4, 4
47	.balignl 16, 0x40200000
48save_reg_insts:       /* must be quad-word aligned. */
49	stqd    $16, 0($3)
50	stqd    $17, 16($3)
51	stqd    $18, 32($3)
52	stqd    $19, 48($3)
53	andi    $5, $4, 0x7F
54	stqr    $4, save_reg_insts
55	ai      $3, $3, 64
56	brnz    $5, save_reg_loop
57
58	/* Initialize the stack pointer to point to 16368
59	 * (16kb-16). The back chain pointer is initialized
60	 * to NULL.
61	 */
62	il	$0, 0
63	il	$SP, 16368
64	stqd	$0, 0($SP)
65
66	/* Allocate a minimum stack frame for the called main.
67	 * This is needed so that main has a place to save the
68	 * link register when it calls another function.
69	 */
70	stqd	$SP, -160($SP)
71	ai	$SP, $SP, -160
72
73	/* Call the program's main function. */
74	brsl	$0, main
75
76	/* In this case main should not return; if it does
77	 * there has been an error in the sequence.  Execute
78	 * stop-and-signal with code=0.
79	 */
80.global exit
81.global	_exit
82exit:
83_exit:
84	stop	0x0
85
86	/* Pad the size of this crt0.o to be multiple of 16 bytes. */
87.balignl 16, 0x0
88
89