{"id":1378,"date":"2012-02-29T15:47:34","date_gmt":"2012-02-28T21:47:34","guid":{"rendered":"http:\/\/peta.okechan.net\/blog\/?p=1378"},"modified":"2012-03-14T11:21:51","modified_gmt":"2012-03-14T02:21:51","slug":"xv6%e3%82%bd%e3%83%bc%e3%82%b9%e3%82%b3%e3%83%bc%e3%83%89%e3%83%aa%e3%83%bc%e3%83%87%e3%82%a3%e3%83%b3%e3%82%b0-%e3%81%9d%e3%81%ae25","status":"publish","type":"post","link":"https:\/\/peta.okechan.net\/blog\/archives\/1378","title":{"rendered":"[xv6 #24] Chapter 2 &#8211; Traps, interrupts, and drivers &#8211; Code: The first system call"},"content":{"rendered":"<p>\u30c6\u30ad\u30b9\u30c8\u306e33\u301c34\u30da\u30fc\u30b8<\/p>\n<h3>\u672c\u6587<\/h3>\n<p>\u524d\u306e\u7ae0\u306f\u3001initcode.S\u304c\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u3092\u547c\u3073\u51fa\u3059\u3068\u3053\u308d\u3067\u7d42\u308f\u3063\u305f\u3002<br \/>\n\u3082\u3046\u4e00\u56de\u305d\u3053\u3092\u898b\u3066\u3088\u3046\u3002<br \/>\n\uff08initcode.S\u306e\u6700\u521d\u306eint $T_SYSCALL\u306e\u3068\u3053\u308d\uff09<br \/>\n\u30d7\u30ed\u30bb\u30b9\u306f\u3001exec\u3092\u547c\u3076\u305f\u3081\u306e\u5f15\u6570\u3092\u305d\u306e\u30d7\u30ed\u30bb\u30b9\u306e\u30b9\u30bf\u30c3\u30af\u306b\u30d7\u30c3\u30b7\u30e5\u3057\u3001%eax\u306b\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u756a\u53f7\u3092\u30bb\u30c3\u30c8\u3059\u308b\u3002<br \/>\n\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u756a\u53f7\u306f\u3001\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u306e\u30c6\u30fc\u30d6\u30eb\u3067\u3042\u308bsyscall\u306e\u914d\u5217\u306e\u30a8\u30f3\u30c8\u30ea\u306e\u3069\u308c\u304b\u3092\u6307\u3059\u3002<br \/>\n\uff08syscall.h\u3068syscall.c\u306e\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u30c6\u30fc\u30d6\u30eb\u3092\u53c2\u7167\uff09<br \/>\n\u6211\u3005\u306f\u3001int\u547d\u4ee4\u304c\u30e6\u30fc\u30b6\u30e2\u30fc\u30c9\u304b\u3089\u30ab\u30fc\u30cd\u30eb\u30e2\u30fc\u30c9\u3078\u5207\u308a\u66ff\u3048\u3001\u30ab\u30fc\u30cd\u30eb\u304c\u6b63\u3057\u3044\u30ab\u30fc\u30cd\u30eb\u306e\u95a2\u6570\uff08\u4f8b\u3048\u3070sys_exec\uff09\u3092\u547c\u3073\u51fa\u3057\u3001\u30ab\u30fc\u30cd\u30eb\u304csys_exec\u306e\u5f15\u6570\u3092\u56de\u5fa9\u51fa\u6765\u308b\u624b\u306f\u305a\u3092\u6574\u3048\u308b\u5fc5\u8981\u304c\u3042\u308b\u3002<br \/>\n\u6b21\u306e\u3044\u304f\u3064\u304b\u306e\u7bc0\u3067\u3001\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u306e\u305f\u3081\u306e\u305d\u308c\u3092xv6\u304c\u3069\u3046\u3084\u3063\u3066\u624b\u306f\u305a\u3092\u6574\u3048\u308b\u304b\u8aac\u660e\u3059\u308b\u3002<br \/>\n\u305d\u3046\u3057\u305f\u3089\u5272\u308a\u8fbc\u307f\u3068\u4f8b\u5916\u306e\u305f\u3081\u306b\u540c\u3058\u30b3\u30fc\u30c9\u304c\u518d\u5229\u7528\u51fa\u6765\u308b\u3053\u3068\u3092\u6211\u3005\u306f\u767a\u898b\u3059\u308b\u3060\u308d\u3046\u3002<\/p>\n<p>initcode.S<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\"># Initial process execs \/init.\n\n#include \"syscall.h\"\n#include \"traps.h\"\n\n\n# exec(init, argv)\n.globl start\nstart:\n  pushl $argv\n  pushl $init\n  pushl $0  \/\/ where caller pc would be\n  movl $SYS_exec, %eax\n  int $T_SYSCALL\n\n# for(;;) exit();\nexit:\n  movl $SYS_exit, %eax\n  int $T_SYSCALL\n  jmp exit\n\n# char init&#x5B;] = \"\/init&#92;&#48;\";\ninit:\n  .string \"\/init&#92;&#48;\"\n\n# char *argv&#x5B;] = { init, 0 };\n.p2align 2\nargv:\n  .long init\n  .long 0<\/pre>\n<p>syscall.h<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\">\/\/ System call numbers\n#define SYS_fork    1\n#define SYS_exit    2\n#define SYS_wait    3\n#define SYS_pipe    4\n#define SYS_read    5\n#define SYS_kill    6\n#define SYS_exec    7\n#define SYS_fstat   8\n#define SYS_chdir   9\n#define SYS_dup    10\n#define SYS_getpid 11\n#define SYS_sbrk   12\n#define SYS_sleep  13\n#define SYS_uptime 14\n\n#define SYS_open   15\n#define SYS_write  16\n#define SYS_mknod  17\n#define SYS_unlink 18\n#define SYS_link   19\n#define SYS_mkdir  20\n#define SYS_close  21<\/pre>\n<p>syscall.c\u306e\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u30c6\u30fc\u30d6\u30eb<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\">static int (*syscalls&#x5B;])(void) = {\n&#x5B;SYS_fork]    sys_fork,\n&#x5B;SYS_exit]    sys_exit,\n&#x5B;SYS_wait]    sys_wait,\n&#x5B;SYS_pipe]    sys_pipe,\n&#x5B;SYS_read]    sys_read,\n&#x5B;SYS_kill]    sys_kill,\n&#x5B;SYS_exec]    sys_exec,\n&#x5B;SYS_fstat]   sys_fstat,\n&#x5B;SYS_chdir]   sys_chdir,\n&#x5B;SYS_dup]     sys_dup,\n&#x5B;SYS_getpid]  sys_getpid,\n&#x5B;SYS_sbrk]    sys_sbrk,\n&#x5B;SYS_sleep]   sys_sleep,\n&#x5B;SYS_uptime]  sys_uptime,\n&#x5B;SYS_open]    sys_open,\n&#x5B;SYS_write]   sys_write,\n&#x5B;SYS_mknod]   sys_mknod,\n&#x5B;SYS_unlink]  sys_unlink,\n&#x5B;SYS_link]    sys_link,\n&#x5B;SYS_mkdir]   sys_mkdir,\n&#x5B;SYS_close]   sys_close,\n};<\/pre>\n<h3>\u611f\u60f3<\/h3>\n<p>\u524d\u3005\u56de\u611f\u60f3\u306b\u300c\u4f8b\u5916\u3067\u3082\u5272\u308a\u8fbc\u307f\u304c\u767a\u751f\u3059\u308b\u3057\u3001\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u3067\u3082\u767a\u751f\u3059\u308b\u3057\u3001\u30c7\u30d0\u30a4\u30b9\u304b\u3089\u3082\u767a\u751f\u3059\u308b\u3068\u3044\u3046\u3053\u3068\u307f\u305f\u3044\u3067\u3059\u3002\u300d\u3068\u66f8\u304d\u307e\u3057\u305f\u3002<br \/>\n\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u306e\u547c\u3073\u51fa\u3057\u306e\u51e6\u7406\u3092\u898b\u308b\u3068\u3001\u5272\u308a\u8fbc\u307f\u3068\u4f8b\u5916\u306b\u3082\u540c\u3058\u3088\u3046\u306a\u51e6\u7406\u304c\u6d41\u7528\u51fa\u6765\u308b\u98a8\u306a\u4e8b\u304c\u3053\u3053\u3067\u3082\u66f8\u3044\u3066\u3042\u308a\u3001\u3084\u306f\u308a\u305d\u306e\u3042\u305f\u308a\u306f\u95a2\u9023\u3057\u3066\u308b\u307f\u305f\u3044\u3067\u3059\u306d\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u30c6\u30ad\u30b9\u30c8\u306e33\u301c34\u30da\u30fc\u30b8<\/p>\n<h3>\u672c\u6587<\/h3>\n<p>\u524d\u306e\u7ae0\u306f\u3001initcode.S\u304c\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u3092\u547c\u3073\u51fa\u3059\u3068\u3053\u308d\u3067\u7d42\u308f\u3063\u305f\u3002<br \/>\n\u3082\u3046\u4e00\u56de\u305d\u3053\u3092\u898b\u3066\u3088\u3046\u3002<br \/>\n\uff08initcode.S\u306e\u6700\u521d\u306eint $T_SYSCALL\u306e\u3068\u3053\u308d\uff09<br \/>\n\u30d7\u30ed\u30bb\u30b9\u306f\u3001exec\u3092\u547c\u3076\u305f\u3081\u306e\u5f15\u6570\u3092\u305d\u306e\u30d7\u30ed\u30bb\u30b9\u306e\u30b9\u30bf\u30c3\u30af\u306b\u30d7\u30c3\u30b7\u30e5\u3057\u3001%eax\u306b\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u756a\u53f7\u3092\u30bb\u30c3\u30c8\u3059\u308b\u3002<br \/>\n\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u756a\u53f7\u306f\u3001\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u306e\u30c6\u30fc\u30d6\u30eb\u3067\u3042\u308bsyscall\u306e\u914d\u5217\u306e\u30a8\u30f3\u30c8\u30ea\u306e\u3069\u308c\u304b\u3092\u6307\u3059\u3002<br \/>\n\uff08syscall.h\u3068syscall.c\u306e\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u30c6\u30fc\u30d6\u30eb\u3092\u53c2\u7167\uff09<br \/>\n\u6211\u3005\u306f\u3001int\u547d\u4ee4\u304c\u30e6\u30fc\u30b6\u30e2\u30fc\u30c9\u304b\u3089\u30ab\u30fc\u30cd\u30eb\u30e2\u30fc\u30c9\u3078\u5207\u308a\u66ff\u3048\u3001\u30ab\u30fc\u30cd\u30eb\u304c\u6b63\u3057\u3044\u30ab\u30fc\u30cd\u30eb\u306e\u95a2\u6570\uff08\u4f8b\u3048\u3070sys_exec\uff09\u3092\u547c\u3073\u51fa\u3057\u3001\u30ab\u30fc\u30cd\u30eb\u304csys_exec\u306e\u5f15\u6570\u3092\u56de\u5fa9\u51fa\u6765\u308b\u624b\u306f\u305a\u3092\u6574\u3048\u308b\u5fc5\u8981\u304c\u3042\u308b\u3002<br \/>\n\u6b21\u306e\u3044\u304f\u3064\u304b\u306e\u7bc0\u3067\u3001\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u306e\u305f\u3081\u306e\u305d\u308c\u3092xv6\u304c\u3069\u3046\u3084\u3063\u3066\u624b\u306f\u305a\u3092\u6574\u3048\u308b\u304b\u8aac\u660e\u3059\u308b\u3002<br \/>\n\u305d\u3046\u3057\u305f\u3089\u5272\u308a\u8fbc\u307f\u3068\u4f8b\u5916\u306e\u305f\u3081\u306b\u540c\u3058\u30b3\u30fc\u30c9\u304c\u518d\u5229\u7528\u51fa\u6765\u308b\u3053\u3068\u3092\u6211\u3005\u306f\u767a\u898b\u3059\u308b\u3060\u308d\u3046\u3002<\/p>\n<p>initcode.S<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\"># Initial process execs \/init.\n\n#include \"syscall.h\"\n#include \"traps.h\"\n\n\n# exec(init, argv)\n.globl start\nstart:\n  pushl $argv\n  pushl $init\n  pushl $0  \/\/ where caller pc would be\n  movl $SYS_exec, %eax\n  int $T_SYSCALL\n\n# for(;;) exit();\nexit:\n  movl $SYS_exit, %eax\n  int $T_SYSCALL\n  jmp exit\n\n# char init&#x5B;] = \"\/init&#92;&#48;\";\ninit:\n  .string \"\/init&#92;&#48;\"\n\n# char *argv&#x5B;] = { init, 0 };\n.p2align 2\nargv:\n  .long init\n  .long 0<\/pre>\n<p>syscall.h<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\">\/\/ System call numbers\n#define SYS_fork    1\n#define SYS_exit    2\n#define SYS_wait    3\n#define SYS_pipe    4\n#define SYS_read    5\n#define SYS_kill    6\n#define SYS_exec    7\n#define SYS_fstat   8\n#define SYS_chdir   9\n#define SYS_dup    10\n#define SYS_getpid 11\n#define SYS_sbrk   12\n#define SYS_sleep  13\n#define SYS_uptime 14\n\n#define SYS_open   15\n#define SYS_write  16\n#define SYS_mknod  17\n#define SYS_unlink 18\n#define SYS_link   19\n#define SYS_mkdir  20\n#define SYS_close  21<\/pre>\n<p>syscall.c\u306e\u95a2\u6570\u30dd\u30a4\u30f3\u30bf\u30c6\u30fc\u30d6\u30eb<\/p>\n<pre class=\"brush: cpp; title: ; notranslate\" title=\"\">static int (*syscalls&#x5B;])(void) = {\n&#x5B;SYS_fork]    sys_fork,\n&#x5B;SYS_exit]    sys_exit,\n&#x5B;SYS_wait]    sys_wait,\n&#x5B;SYS_pipe]    sys_pipe,\n&#x5B;SYS_read]    sys_read,\n&#x5B;SYS_kill]    sys_kill,\n&#x5B;SYS_exec]    sys_exec,\n&#x5B;SYS_fstat]   sys_fstat,\n&#x5B;SYS_chdir]   sys_chdir,\n&#x5B;SYS_dup]     sys_dup,\n&#x5B;SYS_getpid]  sys_getpid,\n&#x5B;SYS_sbrk]    sys_sbrk,\n&#x5B;SYS_sleep]   sys_sleep,\n&#x5B;SYS_uptime]  sys_uptime,\n&#x5B;SYS_open]    sys_open,\n&#x5B;SYS_write]   sys_write,\n&#x5B;SYS_mknod]   sys_mknod,\n&#x5B;SYS_unlink]  sys_unlink,\n&#x5B;SYS_link]    sys_link,\n&#x5B;SYS_mkdir]   sys_mkdir,\n&#x5B;SYS_close]   sys_close,\n};<\/pre>\n<h3>\u611f\u60f3<\/h3>\n<p>\u524d\u3005\u56de\u611f\u60f3\u306b\u300c\u4f8b\u5916\u3067\u3082\u5272\u308a\u8fbc\u307f\u304c\u767a\u751f\u3059\u308b\u3057\u3001\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u3067\u3082\u767a\u751f\u3059\u308b\u3057\u3001\u30c7\u30d0\u30a4\u30b9\u304b\u3089\u3082\u767a\u751f\u3059\u308b\u3068\u3044\u3046\u3053\u3068\u307f\u305f\u3044\u3067\u3059\u3002\u300d\u3068\u66f8\u304d\u307e\u3057\u305f\u3002<br \/>\n\u30b7\u30b9\u30c6\u30e0\u30b3\u30fc\u30eb\u306e\u547c\u3073\u51fa\u3057\u306e\u51e6\u7406\u3092\u898b\u308b\u3068\u3001\u5272\u308a\u8fbc\u307f\u3068\u4f8b\u5916\u306b\u3082\u540c\u3058\u3088\u3046\u306a\u51e6\u7406\u304c\u6d41\u7528\u51fa\u6765\u308b\u98a8\u306a\u4e8b\u304c\u3053\u3053\u3067\u3082\u66f8\u3044\u3066\u3042\u308a\u3001\u3084\u306f\u308a\u305d\u306e\u3042\u305f\u308a\u306f\u95a2\u9023\u3057\u3066\u308b\u307f\u305f\u3044\u3067\u3059\u306d\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[405],"class_list":["post-1378","post","type-post","status-publish","format-standard","hentry","category-tech","tag-xv6"],"_links":{"self":[{"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/posts\/1378","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/comments?post=1378"}],"version-history":[{"count":0,"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/posts\/1378\/revisions"}],"wp:attachment":[{"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/media?parent=1378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/categories?post=1378"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/peta.okechan.net\/blog\/wp-json\/wp\/v2\/tags?post=1378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}