4 * Copyright (C) 2010-2016 Nathan Whitehorn
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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19 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 #include <sys/syscall.h>
34 #include <machine/trap.h>
35 #include <machine/param.h>
36 #include <machine/spr.h>
37 #include <machine/asm.h>
43 /* Glue for linker script */
45 .set kernbase, KERNBASE
58 #define TMPSTKSZ 16384 /* 16K temporary stack */
65 * Entry point for bootloaders that do not fully implement ELF and start
66 * at the beginning of the image (kexec, notably). In its own section so
67 * that it ends up before any linker-generated call stubs and actually at
68 * the beginning of the image. kexec on some systems also enters at
69 * (start of image) + 0x60, so put a spin loop there.
71 .section ".text.kboot", "x", @progbits
74 . = kbootentry + 0x40 /* Magic address used in platform layer */
78 . = kbootentry + 0x60 /* Entry point for kexec APs */
79 ap_kexec_start: /* At 0x60 past start, copied to 0x60 by kexec */
80 /* r3 set to CPU ID by kexec */
82 /* Invalidate icache for low-memory copy and jump there */
88 ba 0x80 /* Absolute branch to next inst */
90 . = kbootentry + 0x80 /* Aligned to cache line */
91 1: or 31,31,31 /* yield */
93 lwz %r1,0x40(0) /* Spin on ap_kexec_spin_sem */
94 cmpw %r1,%r3 /* Until it equals our CPU ID */
98 or 2,2,2 /* unyield */
103 * Now start the real text section
111 * Main kernel entry point.
113 * Calling convention:
114 * r3: Flattened Device Tree pointer (or zero)
116 * r5: OF client interface pointer (or zero)
117 * r6: Loader metadata pointer (or zero)
118 * r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
121 ASENTRY_NOPROF(__start)
122 /* Set 64-bit mode if not yet set before branching to C */
128 nop /* Make this block a multiple of 8 bytes */
130 /* Set up the TOC pointer */
135 .llong __tocbase + 0x8000 - .
140 /* Get load offset */
141 ld %r31,-0x8000(%r2) /* First TOC entry is TOC base */
142 subf %r31,%r31,%r2 /* Subtract from real TOC base to get base */
144 /* Set up the stack pointer */
145 ld %r1,TOC_REF(tmpstk)(%r2)
146 addi %r1,%r1,TMPSTKSZ-96
149 /* Relocate kernel */
171 mr %r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
175 /* Set stack pointer to new value and branch to mi_startup */
185 #include <powerpc/aim/trap_subr64.S>