| 1 | |
| 2 | |
| 3 | * arch/alpha/boot/main.c
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| 4 | *
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| 5 | * Copyright (C) 1994, 1995 Linus Torvalds
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| 6 | *
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| 7 | * This file is the bootloader for the Linux/AXP kernel
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| 8 |
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| 9 | #include <linux/kernel.h>
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| 10 | #include <linux/slab.h>
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| 11 | #include <linux/string.h>
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| 12 | #include <generated/utsrelease.h>
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| 13 | #include <linux/mm.h>
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| 14 |
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| 15 | #include <asm/console.h>
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| 16 | #include <asm/hwrpb.h>
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| 17 |
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| 18 | #include <linux/stdarg.h>
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| 19 |
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| 20 | #include "ksize.h"
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| 21 |
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| 22 | extern unsigned long switch_to_osf_pal(unsigned long nr,
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| 23 | struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
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| 24 | unsigned long *vptb);
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| 25 | struct hwrpb_struct *hwrpb = INIT_HWRPB;
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| 26 | static struct pcb_struct pcb_va[1];
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| 27 |
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| 28 | |
| 29 | * Find a physical address of a virtual object..
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| 30 | *
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| 31 | * This is easy using the virtual page table address.
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| 32 |
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| 33 |
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| 34 | static inline void *
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| 35 | find_pa(unsigned long *vptb, void *ptr)
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| 36 | {
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| 37 | unsigned long address = (unsigned long) ptr;
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| 38 | unsigned long result;
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| 39 |
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| 40 | result = vptb[address >> 13];
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| 41 | result >>= 32;
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| 42 | result <<= 13;
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| 43 | result |= address & 0x1fff;
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| 44 | return (void *) result;
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| 45 | }
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| 46 |
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| 47 | |
| 48 | * This function moves into OSF/1 pal-code, and has a temporary
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| 49 | * PCB for that. The kernel proper should replace this PCB with
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| 50 | * the real one as soon as possible.
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| 51 | *
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| 52 | * The page table muckery in here depends on the fact that the boot
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| 53 | * code has the L1 page table identity-map itself in the second PTE
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| 54 | * in the L1 page table. Thus the L1-page is virtually addressable
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| 55 | * itself (through three levels) at virtual address 0x200802000.
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| 56 |
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| 57 |
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| 58 | #define VPTB ((unsigned long *) 0x200000000)
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| 59 | #define L1 ((unsigned long *) 0x200802000)
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| 60 |
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| 61 | void
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| 62 | pal_init(void)
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| 63 | {
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| 64 | unsigned long i, rev;
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| 65 | struct percpu_struct * percpu;
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| 66 | struct pcb_struct * pcb_pa;
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| 67 |
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| 68 |
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| 69 | pcb_va->ksp = 0;
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| 70 | pcb_va->usp = 0;
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| 71 | pcb_va->ptbr = L1[1] >> 32;
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| 72 | pcb_va->asn = 0;
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| 73 | pcb_va->pcc = 0;
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| 74 | pcb_va->unique = 0;
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| 75 | pcb_va->flags = 1;
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| 76 | pcb_va->res1 = 0;
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| 77 | pcb_va->res2 = 0;
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| 78 | pcb_pa = find_pa(VPTB, pcb_va);
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| 79 |
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| 80 | |
| 81 | * a0 = 2 (OSF)
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| 82 | * a1 = return address, but we give the asm the vaddr of the PCB
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| 83 | * a2 = physical addr of PCB
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| 84 | * a3 = new virtual page table pointer
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| 85 | * a4 = KSP (but the asm sets it)
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| 86 |
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| 87 | srm_printk("Switching to OSF PAL-code .. ");
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| 88 |
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| 89 | i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
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| 90 | if (i) {
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| 91 | srm_printk("failed, code %ld\n", i);
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| 92 | __halt();
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| 93 | }
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| 94 |
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| 95 | percpu = (struct percpu_struct *)
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| 96 | (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
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| 97 | rev = percpu->pal_revision = percpu->palcode_avail[2];
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| 98 |
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| 99 | srm_printk("Ok (rev %lx)\n", rev);
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| 100 |
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| 101 | tbia();
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| 102 | }
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| 103 |
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| 104 | static inline long openboot(void)
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| 105 | {
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| 106 | char bootdev[256];
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| 107 | long result;
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| 108 |
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| 109 | result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);
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| 110 | if (result < 0)
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| 111 | return result;
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| 112 | return callback_open(bootdev, result & 255);
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| 113 | }
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| 114 |
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| 115 | static inline long close(long dev)
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| 116 | {
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| 117 | return callback_close(dev);
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| 118 | }
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| 119 |
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| 120 | static inline long load(long dev, unsigned long addr, unsigned long count)
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| 121 | {
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| 122 | char bootfile[256];
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| 123 | extern char _end;
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| 124 | long result, boot_size = &_end - (char *) BOOT_ADDR;
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| 125 |
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| 126 | result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);
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| 127 | if (result < 0)
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| 128 | return result;
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| 129 | result &= 255;
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| 130 | bootfile[result] = '\0';
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| 131 | if (result)
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| 132 | srm_printk("Boot file specification (%s) not implemented\n",
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| 133 | bootfile);
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| 134 | return callback_read(dev, count, (void *)addr, boot_size/512 + 1);
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| 135 | }
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| 136 |
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| 137 | |
| 138 | * Start the kernel.
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| 139 |
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| 140 | static void runkernel(void)
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| 141 | {
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| 142 | __asm__ __volatile__(
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| 143 | "bis %1,%1,$30\n\t"
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| 144 | "bis %0,%0,$26\n\t"
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| 145 | "ret ($26)"
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| 146 | :
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| 147 | : "r" (START_ADDR),
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| 148 | "r" (PAGE_SIZE + INIT_STACK));
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| 149 | }
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| 150 |
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| 151 | void start_kernel(void)
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| 152 | {
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| 153 | long i;
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| 154 | long dev;
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| 155 | int nbytes;
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| 156 | char envval[256];
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| 157 |
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| 158 | srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
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| 159 | if (INIT_HWRPB->pagesize != 8192) {
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| 160 | srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);
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| 161 | return;
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| 162 | }
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| 163 | pal_init();
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| 164 | dev = openboot();
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| 165 | if (dev < 0) {
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| 166 | srm_printk("Unable to open boot device: %016lx\n", dev);
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| 167 | return;
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| 168 | }
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| 169 | dev &= 0xffffffff;
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| 170 | srm_printk("Loading vmlinux ...");
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| 171 | i = load(dev, START_ADDR, KERNEL_SIZE);
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| 172 | close(dev);
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| 173 | if (i != KERNEL_SIZE) {
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| 174 | srm_printk("Failed (%lx)\n", i);
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| 175 | return;
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| 176 | }
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| 177 |
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| 178 | nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
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| 179 | if (nbytes < 0) {
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| 180 | nbytes = 0;
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| 181 | }
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| 182 | envval[nbytes] = '\0';
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| 183 | strcpy((char*)ZERO_PGE, envval);
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| 184 |
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| 185 | srm_printk(" Ok\nNow booting the kernel\n");
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| 186 | runkernel();
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| 187 | for (i = 0 ; i < 0x100000000 ; i++)
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| 188 | ;
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| 189 | __halt();
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| 190 | }
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