Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* kernel_thread.S: kernel thread creation |
| 2 | * |
| 3 | * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/linkage.h> |
| 13 | #include <asm/unistd.h> |
| 14 | |
| 15 | #define CLONE_VM 0x00000100 /* set if VM shared between processes */ |
| 16 | #define KERN_ERR "<3>" |
| 17 | |
| 18 | .section .rodata |
| 19 | kernel_thread_emsg: |
| 20 | .asciz KERN_ERR "failed to create kernel thread: error=%d\n" |
| 21 | |
| 22 | .text |
| 23 | .balign 4 |
| 24 | |
| 25 | ############################################################################### |
| 26 | # |
| 27 | # Create a kernel thread |
| 28 | # |
| 29 | # int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) |
| 30 | # |
| 31 | ############################################################################### |
| 32 | .globl kernel_thread |
| 33 | .type kernel_thread,@function |
| 34 | kernel_thread: |
| 35 | or.p gr8,gr0,gr4 |
| 36 | or gr9,gr0,gr5 |
| 37 | |
| 38 | # start by forking the current process, but with shared VM |
| 39 | setlos.p #__NR_clone,gr7 ; syscall number |
| 40 | ori gr10,#CLONE_VM,gr8 ; first syscall arg [clone_flags] |
| 41 | sethi.p #0xe4e4,gr9 ; second syscall arg [newsp] |
| 42 | setlo #0xe4e4,gr9 |
| 43 | setlos.p #0,gr10 ; third syscall arg [parent_tidptr] |
| 44 | setlos #0,gr11 ; fourth syscall arg [child_tidptr] |
| 45 | tira gr0,#0 |
| 46 | setlos.p #4095,gr7 |
| 47 | andcc gr8,gr8,gr0,icc0 |
| 48 | addcc.p gr8,gr7,gr0,icc1 |
| 49 | bnelr icc0,#2 |
| 50 | bc icc1,#0,kernel_thread_error |
| 51 | |
| 52 | # now invoke the work function |
| 53 | or gr5,gr0,gr8 |
| 54 | calll @(gr4,gr0) |
| 55 | |
| 56 | # and finally exit the thread |
| 57 | setlos #__NR_exit,gr7 ; syscall number |
| 58 | tira gr0,#0 |
| 59 | |
| 60 | kernel_thread_error: |
| 61 | subi sp,#8,sp |
| 62 | movsg lr,gr4 |
| 63 | sti gr8,@(sp,#0) |
| 64 | sti.p gr4,@(sp,#4) |
| 65 | |
| 66 | or gr8,gr0,gr9 |
| 67 | sethi.p %hi(kernel_thread_emsg),gr8 |
| 68 | setlo %lo(kernel_thread_emsg),gr8 |
| 69 | |
| 70 | call printk |
| 71 | |
| 72 | ldi @(sp,#4),gr4 |
| 73 | ldi @(sp,#0),gr8 |
| 74 | subi sp,#8,sp |
| 75 | jmpl @(gr4,gr0) |
| 76 | |
| 77 | .size kernel_thread,.-kernel_thread |