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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * arch/alpha/kernel/head.S
4 *
5 * initial boot stuff.. At this point, the bootloader has already
6 * switched into OSF/1 PAL-code, and loaded us at the correct address
7 * (START_ADDR). So there isn't much left for us to do: just set up
8 * the kernel global pointer and jump to the kernel entry-point.
9 */
10
11#include <linux/init.h>
12#include <asm/asm-offsets.h>
13#include <asm/pal.h>
14#include <asm/setup.h>
15
16__HEAD
17.globl _stext
18 .set noreorder
19 .globl __start
20 .ent __start
21_stext:
22__start:
23 .prologue 0
24 br $27,1f
251: ldgp $29,0($27)
26 /* We need to get current_task_info loaded up... */
27 lda $8,init_thread_union
28 /* ... and find our stack ... */
29 lda $30,0x4000 - SIZEOF_PT_REGS($8)
30 /* ... and then we can start the kernel. */
31 jsr $26,start_kernel
32 call_pal PAL_halt
33 .end __start
34
35#ifdef CONFIG_SMP
36 .align 3
37 .globl __smp_callin
38 .ent __smp_callin
39 /* On entry here from SRM console, the HWPCB of the per-cpu
40 slot for this processor has been loaded. We've arranged
41 for the UNIQUE value for this process to contain the PCBB
42 of the target idle task. */
43__smp_callin:
44 .prologue 1
45 ldgp $29,0($27) # First order of business, load the GP.
46
47 call_pal PAL_rduniq # Grab the target PCBB.
48 mov $0,$16 # Install it.
49 call_pal PAL_swpctx
50
51 lda $8,0x3fff # Find "current".
52 bic $30,$8,$8
53
54 jsr $26,smp_callin
55 call_pal PAL_halt
56 .end __smp_callin
57#endif /* CONFIG_SMP */
58
59 #
60 # The following two functions are needed for supporting SRM PALcode
61 # on the PC164 (at least), since that PALcode manages the interrupt
62 # masking, and we cannot duplicate the effort without causing problems
63 #
64
65 .align 3
66 .globl cserve_ena
67 .ent cserve_ena
68cserve_ena:
69 .prologue 0
70 bis $16,$16,$17
71 lda $16,52($31)
72 call_pal PAL_cserve
73 ret ($26)
74 .end cserve_ena
75
76 .align 3
77 .globl cserve_dis
78 .ent cserve_dis
79cserve_dis:
80 .prologue 0
81 bis $16,$16,$17
82 lda $16,53($31)
83 call_pal PAL_cserve
84 ret ($26)
85 .end cserve_dis
86
87 #
88 # It is handy, on occasion, to make halt actually just loop.
89 # Putting it here means we dont have to recompile the whole
90 # kernel.
91 #
92
93 .align 3
94 .globl halt
95 .ent halt
96halt:
97 .prologue 0
98 call_pal PAL_halt
99 .end halt