{"id":1362,"date":"2010-09-16T11:26:32","date_gmt":"2010-09-16T03:26:32","guid":{"rendered":"http:\/\/edsionte.com\/techblog\/?p=1362"},"modified":"2011-03-14T21:13:50","modified_gmt":"2011-03-14T13:13:50","slug":"%e5%ad%97%e7%ac%a6%e8%ae%be%e5%a4%87%e9%a9%b1%e5%8a%a8%e5%88%86%e6%9e%90","status":"publish","type":"post","link":"http:\/\/edsionte.com\/techblog\/archives\/1362","title":{"rendered":"\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u5206\u6790(1)"},"content":{"rendered":"

Last Update:9\/24\uff08\u659c\u4f53\u5b57\u4e3a\u66f4\u65b0\u5185\u5bb9\uff09<\/span><\/em><\/strong><\/p>\n

Last Update:9\/20<\/span><\/em><\/strong><\/del><\/p>\n

Last Update:9\/19<\/em><\/strong><\/del><\/p>\n

\u719f\u6089\u4e86\u6a21\u5757\u7f16\u7a0b\u7684\u57fa\u672c\u6846\u67b6\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u8bd5\u7740\u5206\u6790\u4e00\u4e2a\u7b80\u5355\u7684\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u3002\u4e0b\u9762\u4ee5\u300a\u8bbe\u5907\u9a71\u52a8\u5f00\u53d1\u8be6\u89e3\u300b\u4e00\u4e66\u4e2d\u7684\u4ee3\u78016.17\u4e3a\u4f8b\u6765\u5206\u6790\u8fd9\u4e2a\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u7684\u4ee3\u7801\u3002<\/p>\n

\u6211\u4eec\u73b0\u5728\u5bf9\u4e8e\u5bf9\u524d\u6587\u4e2dhello\uff0ckernel\u5185\u6838\u6a21\u5757\u8fdb\u884c\u7a0d\u5fae\u7684\u6539\u52a8\u3002\u6211\u4eec\u90fd\u77e5\u9053\u5185\u6838\u6a21\u5757\u7684\u5165\u53e3\u51fd\u6570\u662fmodule_init\uff08function name\uff09\u5185\u6ce8\u518c\u7684\u51fd\u6570\u3002\u4e5f\u5c31\u662f\u544a\u8bc9\u5185\u6838\u201c\u4ece\u8fd9\u4e2a\u51fd\u6570\u5165\u53e3\u201d\u3002\u90a3\u4e48\u6211\u4eec\u5206\u6790\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u6a21\u5757\uff0c\u9996\u5148\u5e94\u8be5\u53bb\u770bglobalmem_init\u51fd\u6570\u3002<\/p>\n

module_init(globalmem_init);\r\nmodule_exit(globalmem_exit);<\/pre>\n
\u5728globalmem_init\u51fd\u6570\u4e2d\uff0c\u9996\u5148\u901a\u8fc7\u5b8fMKDEV\u83b7\u5f9732\u4f4d\u7684\u8bbe\u5907\u9a71\u52a8\u53f7\u3002\u901a\u5e38linux\u4e2d\u7684\u8bbe\u5907\u53f7\u7531\u4e3b\u8bbe\u5907\u53f7\u548c\u6b21\u8bbe\u5907\u53f7\u7ec4\u6210\uff0c\u4e3b\u8bbe\u5907\u53f7\u5bf9\u5e94\u6bcf\u4e00\u7c7b\u8bbe\u5907\uff0c\u800c\u6b21\u8bbe\u5907\u53f7\u5bf9\u5e94\u8be5\u7c7b\u8bbe\u5907\u7684\u5177\u4f53\u4e00\u4e2a\u8bbe\u5907\u3002dev_t\u7c7b\u578b\u524d12\u4f4d\u662f\u4e3b\u8bbe\u5907\u53f7\uff08\u4f46\u4e8b\u5b9e\u4e0a\u4e3b\u8bbe\u5907\u53f7\u7684\u524d\u56db\u4f4d\u88ab\u5c4f\u853d\u4e86\uff0c\u5982\u679c\u53bb\u770b\u6e90\u7801\u5c31\u53ef\u5f97\u77e5\uff09\uff0c<\/em>\u540e20\u4f4d\u4e3a\u6b21\u8bbe\u5907\u53f7\u3002\u7531\u4e8e\u53ef\u4ee5\u4e8b\u5148\u6307\u5b9a\u4e3b\u8bbe\u5907\u53f7globalmem_major\uff0c\u56e0\u6b64\u6211\u4eec\u9700\u8981\u7528\u5b8fMKDEV\u6765\u83b7\u5f97dev_t\u7c7b\u578b\u7684\u8bbe\u5907\u53f7\uff1a<\/p>\n
#define MINORBITS       20\r\n#define MKDEV(ma,mi)    (((ma) << MINORBITS) | (mi))<\/pre>\n
\u8fd9\u4e2a\u5b8f\u901a\u8fc7\u79fb\u4f4d\u548c\u6216\u8fd0\u7b97\uff0c\u5de7\u5999\u7684\u5f97\u5230dev_t\u7c7b\u578b\u7684\u8bbe\u5907\u53f7\u3002\u8fd9\u4e2a\u5b8f\u53ef\u4ee5\u5728include\/linux\/kdev_t.h\u4e2d\u67e5\u627e\u5230\u3002\u7f51\u4e0a\u6709\u7684\u8d44\u6599\u4e2d\u4f1a\u7ed9\u51faMINORBITS\u4e3a8\uff0c\u8fd9\u4e2a\u5e94\u8be5\u662f\u9002\u540816\u4f4d\u7684\u8bbe\u5907\u53f7\u7684\u60c5\u51b5\u3002<\/p>\n
\u63a5\u7740\u901a\u8fc7\u5168\u5c40\u53d8\u91cfglobamem_major\u6765\u5224\u65ad\u662f\u5426\u4e8b\u5148\u5206\u914d\u4e86\u8d77\u59cb\u7684\u8bbe\u5907\u53f7\u3002\u5982\u679c\u662f\uff0c\u5219\u7ee7\u7eed\u5206\u914d\u8fde\u7eed\u7684\u4e00\u6bb5\u8bbe\u5907\u53f7\uff0c\u5426\u5219\u52a8\u6001\u5206\u914d\u8bbe\u5907\u53f7\uff0c\u5e76\u4e14\u901a\u8fc7MAJOR\u5b8f\u83b7\u5f97\u5206\u914d\u4ee5\u540e\u7684\u4e3b\u8bbe\u5907\u53f7\u3002\u8fd9\u91cc\u9700\u8981\u5f3a\u8c03\u7684\u662f\uff0c\u4e0b\u9762\u7684\u4e24\u79cd\u8bbe\u5907\u53f7\u5206\u914d\u51fd\u6570\uff0c\u90fd\u662f\u4e00\u6b21\u6027\u5206\u914d\u4e00\u7ec4\u8fde\u7eed\u7684\u8bbe\u5907\u53f7\uff08\u5f53\u7136\u4e5f\u53ef\u4ee5\u53ea\u5206\u914d\u4e00\u4e2a\u8bbe\u5907\u53f7\uff0c\u8c03\u6574\u53c2\u6570\u5373\u53ef\uff09\u3002<\/em><\/p>\n
\u9996\u5148\u6211\u4eec\u5206\u6790\u5df2\u77e5\u8d77\u59cb\u8bbe\u5907\u53f7\u7684\u60c5\u51b5\u3002\u901a\u8fc7\u8c03\u7528register_chrdev_region\u51fd\u6570\uff0c\u4fbf\u53ef\u4ee5\u7533\u8bf7\u5230\u4e00\u7ec4\u8fde\u7eed\u8303\u56f4\u7684\u8bbe\u5907\u53f7\u3002\u5728linux\/fs\/char_dev.c\u4e2d\u53ef\u4ee5\u770b\u5230\u6b64\u51fd\u6570\u7684\u539f\u578b\u3002<\/p>\n
 int register_chrdev_region(dev_t from, unsigned count, const char *name);<\/pre>\n
\u5176\u4e2dfrom\u662f\u9996\u8bbe\u5907\u53f7\uff0c\u800ccount\u662f\u8fd9\u7ec4\u8fde\u7eed\u8bbe\u5907\u53f7\u7684\u6570\u76ee\u3002name\u4e3a\u8bbe\u5907\u540d\u3002\u800c\u300a\u8bbe\u5907\u300b\u4e00\u4e66\u4e2d\u7684count\u4e3a1\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u8fd9\u7ec4\u8bbe\u5907\u53f7\u7684\u6570\u91cf\u4e3a1\u3002<\/em><\/p>\n
\u5176\u6b21\uff0c\u5f53\u8d77\u59cb\u8bbe\u5907\u53f7\u5e76\u672a\u6307\u5b9a\u65f6\u5c31\u8981\u52a8\u6001\u7684\u7533\u8bf7\u4e86\uff0c\u4f7f\u7528\u4e0b\u9762\u7684\u51fd\u6570\uff1a<\/em><\/p>\n
int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,const char *name);<\/pre>\n
\u4e0e\u4e0a\u9762\u9759\u6001\u5206\u914d\u51fd\u6570\u4e0d\u540c\u7684\u662f\uff0c\u6b64\u65f6dev\u662f\u4e00\u4e2a\u6307\u9488\u7c7b\u578b\uff0c\u56e0\u4e3a\u8981\u8fd4\u56de\u5c06\u8981\u5206\u914d\u7684\u8bbe\u5907\u53f7\u3002\u5173\u4e8e\u4ee5\u4e0a\u4e24\u4e2a\u51fd\u6570\u7684\u5185\u6838\u6e90\u7801\u5206\u6790\uff0c\u5177\u4f53\u53c2\u89c1<\/em>\u8fd9\u91cc<\/em><\/a>\u3002<\/em><\/p>\n
\u4ee5\u4e0a\u90fd\u6210\u529f\u6267\u884c\u540e\uff0c\u6211\u4eec\u7ed9globalmem_devp\u6307\u9488\u5206\u914d\u5185\u5b58\u7a7a\u95f4\u3002\u5176\u4e2dglobalmem_devp\u662f\u4e00\u4e2a\u6307\u5411globalmem\u8bbe\u5907\u7ed3\u6784\u4f53\u7684\u6307\u9488\u3002\u6211\u4eec\u901a\u8fc7mmset\u5bf9\u6b64\u5757\u5185\u5b58\u7a7a\u95f4\u8fdb\u884c\u521d\u59cb\u5316\u4e4b\u540e\u3002\u63a5\u7740globalmem_setup_cdev\u51fd\u6570\u5bf9cdev\u521d\u59cb\u5316\u5e76\u5c06\u6b64\u5b57\u7b26\u8bbe\u5907\u6ce8\u518c\u5230\u5185\u6838\u3002<\/p>\n
\/\/\u8bbe\u5907\u9a71\u52a8\u6a21\u5757\u52a0\u8f7d\u51fd\u6570\r\nint globalmem_init(void)\r\n{\r\n\tint result;\r\n\tdev_t devno=MKDEV(globalmem_major,0);\r\n\r\n\tif(globalmem_major)\r\n\t{\r\n\t\tresult=register_chrdev_region(devno,1,\"globalmem\");\r\n\t}\r\n\telse\r\n\t{\r\n\t\tresult=alloc_chrdev_region(&devno,0,1,\"globalmem\");\r\n\t\tglobalmem_major=MAJOR(devno);\r\n\t}\r\n\tif(result<0)\r\n\t\treturn result;\r\n\tglobalmem_devp=kmalloc(sizeof(struct globalmem_dev),GFP_KERNEL);\r\n\tif(!globalmem_devp)\r\n\t{\r\n\t\tresult=-ENOMEM;\r\n\t\tgoto fail_malloc;\r\n\t}\r\n\r\n\tmemset(globalmem_devp,0,sizeof(struct globalmem_dev));\r\n\r\n\tglobalmem_setup_cdev(globalmem_devp,0);\r\n\treturn 0;\r\nfail_malloc:unregister_chrdev_region(devno,1);\r\n\treturn result;\r\n}<\/pre>\n
\u4e0a\u9762\u7684\u7a0b\u5e8f\u5df2\u7ecf\u5f88\u201c\u6574\u9f50\u201d\u7684\u8bf4\u660e\u4e86init\u51fd\u6570\u7684\u4e3b\u8981\u4f5c\u7528\u3002\u5177\u4f53\u5982\u4e0b\uff1a<\/p>\n
1.\u7533\u8bf7\u8bbe\u5907\u53f7<\/p>\n
2.\u4e3a\u8bbe\u5907\u76f8\u5173\u7684\u6570\u636e\u7ed3\u6784\u5206\u914d\u5185\u5b58<\/p>\n
3.\u521d\u59cb\u5316\u5e76\u6ce8\u518ccdev(globalmem_setup_cdev\u51fd\u6570\u5b9e\u73b0)<\/p>\n
\u6709\u4e86\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\u7684\u52a0\u8f7d\u51fd\u6570\uff0c\u90a3\u4e48\u80af\u5b9a\u6709\u5378\u8f7d\u51fd\u6570\uff1a<\/p>\n
void globalmem_exit(void)\r\n{\r\ncdev_del(&globalmem_devp->cdev);\r\nkfree(globalmem_devp);\r\nunregister_chrdev_region(MKDEV(globalmem_major, 0), 1);\r\n}<\/pre>\n
\u603b\u4f53\u6765\u770b\uff0cglobalmem_init\u51fd\u6570\u5b8c\u6210\u7684\u662f\u5b57\u7b26\u8bbe\u5907\u7684\u4e00\u4e9b\u521d\u59cb\u5316\u5de5\u4f5c\uff0c\u4ee5\u53ca\u5411\u7cfb\u7edf\u5185\u6ce8\u518c\u3002\u800cglobalmem_exit\u5c31\u662f\u8fdb\u884c\u5b57\u7b26\u8bbe\u5907\u7684\u91ca\u653e\u5de5\u4f5c\uff1a\u4ece\u5185\u6838\u4e2d\u5220\u9664\u8fd9\u4e2a\u5b57\u7b26\u8bbe\u5907\uff0c\u91ca\u653e\u8bbe\u5907\u7ed3\u6784\u4f53\u6240\u5360\u7684\u5185\u5b58\uff0c\u4ee5\u53ca\u91ca\u653e\u7533\u8bf7\u7684\u8bbe\u5907\u53f7\u3002\u4ece\u7ed3\u6784\u4e0a\u770b\uff0c\u5b83\u5e76\u6ca1\u6709\u504f\u79bb\u5185\u6838\u6a21\u5757\u7f16\u7a0b\u7684\u7ed3\u6784\u8303\u56f4\uff0c\u4ecd\u7136\u662f\u6211\u4eec\u719f\u6089\u7684hello,kernel\u3002<\/p>\n
\u6211\u4eec\u5728\u6b64\u5148\u6682\u65f6\u5c06globalmem_setup_cdev\u51fd\u6570\u5185\u90e8\u7684\u5b9e\u73b0\u7528return 0;\u6765\u4ee3\u66ff\u3002\u90a3\u4e48\u6211\u4eec\u73b0\u5728\u7528\u63d2\u5165\u5185\u6838\u6a21\u5757\u7684\u547d\u4ee4\u5c06\u6211\u4eec\u8fd9\u4e2a\u5b57\u7b26\u8bbe\u5907\u9a71\u52a8\uff08\u5c3d\u7ba1\u8bb8\u591a\u529f\u80fd\u8fd8\u672a\u5b9e\u73b0\uff09\u63d2\u5165\u5230\u5185\u6838\u4e2d\u3002\u6210\u529f\u540e\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7cat \/proc\/devices \u547d\u4ee4\u6765\u67e5\u770b\u521a\u521a\u5b57\u7b26\u8bbe\u5907\u540d\u79f0\u4ee5\u53ca\u4e3b\u8bbe\u5907\u53f7\u3002\/proc\u662f\u4e00\u4e2a\u865a\u62df\u7684\u6587\u4ef6\u7cfb\u7edf\uff0c\u8fd9\u91cc\u7684\u865a\u62df\u662f\u6307\u8fd9\u4e2a\u6587\u4ef6\u7cfb\u7edf\u5e76\u4e0d\u5360\u7528\u78c1\u76d8\u7a7a\u95f4\u800c\u53ea\u5b58\u5728\u4e8e\u5185\u5b58\u4e2d\u3002\u800c\u8be5\u76ee\u5f55\u4e0b\u7684devices\u6587\u4ef6\u4e2d\u5b58\u50a8\u7740\u7cfb\u7edf\u5b57\u7b26\u548c\u5757\u8bbe\u5907\u7684\u9a71\u52a8\u540d\u79f0\u4ee5\u53ca\u8bbe\u5907\u7f16\u53f7\u3002<\/p>\n
\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7:mknod \/dev\/globalmem c 250 0\u547d\u4ee4\u521b\u5efa\u4e00\u4e2a\u8bbe\u5907\u8282\u70b9\u3002\u6709\u4e86\u8fd9\u4e2a\u8bbe\u5907\u8282\u70b9\u540e\uff0c\u5c31\u53ef\u4ee5\u5bf9\u5b83\u8fdb\u884c\u7c7b\u4f3c\u666e\u901a\u6587\u4ef6\u90a3\u6837\u7684\u64cd\u4f5c\u4e86\uff08\u5f53\u7136\u73b0\u5728\u8fd8\u4e0d\u80fd\uff0c\u56e0\u4e3a\u5e76\u672a\u5b9e\u73b0\u5177\u4f53\u7684\u64cd\u4f5c\u51fd\u6570\uff09\u3002<\/p>\n
\u8fd9\u6837\u4e00\u4e2a\u5b57\u7b26\u9a71\u52a8\u7684\u5927\u81f4\u4e0a\u6709\u4e86\u96cf\u5f62\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
Last Update:9\/24\uff08\u659c\u4f53\u5b57\u4e3a\u66f4\u65b0\u5185\u5bb9\uff09 Last Update:9\/20 Last Update […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[146],"tags":[134,152,403],"class_list":["post-1362","post","type-post","status-publish","format-standard","hentry","category-146","tag-kernel","tag-152","tag-403"],"views":16649,"_links":{"self":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts\/1362","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/comments?post=1362"}],"version-history":[{"count":0,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/posts\/1362\/revisions"}],"wp:attachment":[{"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/media?parent=1362"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/categories?post=1362"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/edsionte.com\/techblog\/wp-json\/wp\/v2\/tags?post=1362"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}