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<?xml version="1.0" encoding="gb2312"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"/><title>linux for ppc chapter 3                jacobw </title></head><body><center><h1>BBS 水木清华站∶精华区</h1></center><a name="top"></a>发信人:&nbsp;plato&nbsp;(纯真年代),&nbsp;信区:&nbsp;Embedded&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />标&nbsp;&nbsp;题:&nbsp;linux&nbsp;for&nbsp;ppc&nbsp;chapter&nbsp;3&nbsp;<br />发信站:&nbsp;BBS&nbsp;水木清华站&nbsp;(Wed&nbsp;May&nbsp;30&nbsp;23:09:22&nbsp;2001)&nbsp;<br />&nbsp;<br />Next&nbsp;Previous&nbsp;Contents&nbsp;<br />----------------------------------------------------------------------------&nbsp;<br />----&nbsp;<br />3.&nbsp;Target&nbsp;Hardware&nbsp;<br />Start&nbsp;by&nbsp;picking&nbsp;the&nbsp;processor&nbsp;which&nbsp;most&nbsp;closely&nbsp;matches&nbsp;your&nbsp;I/O&nbsp;requireme&nbsp;<br />nts,&nbsp;and&nbsp;work&nbsp;out&nbsp;roughly&nbsp;how&nbsp;much&nbsp;RAM&nbsp;and&nbsp;ROM&nbsp;space&nbsp;you&nbsp;need.&nbsp;Then&nbsp;see&nbsp;if&nbsp;y&nbsp;<br />ou&nbsp;can&nbsp;find&nbsp;an&nbsp;off-the-shelf&nbsp;board&nbsp;which&nbsp;also&nbsp;most&nbsp;closely&nbsp;matches&nbsp;what&nbsp;you&nbsp;&nbsp;<br />need.&nbsp;<br />3.1&nbsp;CPU&nbsp;<br />4xx&nbsp;<br /><a href="http://www.borg.umn.edu/~grant/Linux/">http://www.borg.umn.edu/~grant/Linux/</a>&nbsp;<br />IBM&nbsp;405GP&nbsp;<br /><a href="http://www.mvista.com/products/405gp_status/main">http://www.mvista.com/products/405gp_status/main</a>&nbsp;and&nbsp;<a href="http://www.chips.ibm.co">http://www.chips.ibm.co</a>&nbsp;<br />m/products/powerpc/linux/&nbsp;<br />7xx&nbsp;<br /><a href="ftp://ftp.mvista.com/pub/Area51/ppc-7xx">ftp://ftp.mvista.com/pub/Area51/ppc-7xx</a>&nbsp;and&nbsp;<a href="http://www.chips.ibm.com/product">http://www.chips.ibm.com/product</a>&nbsp;<br />s/powerpc/linux/&nbsp;<br />These&nbsp;devices&nbsp;are&nbsp;all&nbsp;covered&nbsp;in&nbsp;the&nbsp;MontaVista&nbsp;kernel.&nbsp;<br />Motorola&nbsp;8xx&nbsp;<br /><a href="http://mot-sps.com/products/microprocessors/32_bit/mpc800/">http://mot-sps.com/products/microprocessors/32_bit/mpc800/</a>&nbsp;<br />Information&nbsp;from&nbsp;Motorola&nbsp;is&nbsp;fragmented,&nbsp;because&nbsp;the&nbsp;850/860&nbsp;and&nbsp;823&nbsp;are&nbsp;han&nbsp;<br />dled&nbsp;by&nbsp;different&nbsp;groups.&nbsp;Information&nbsp;about&nbsp;the&nbsp;bits&nbsp;they&nbsp;have&nbsp;in&nbsp;common&nbsp;is&nbsp;&nbsp;<br />generally&nbsp;equally&nbsp;applicable&nbsp;to&nbsp;both,&nbsp;so&nbsp;it's&nbsp;worth&nbsp;perusing&nbsp;the&nbsp;823&nbsp;resourc&nbsp;<br />es&nbsp;even&nbsp;if&nbsp;you're&nbsp;using&nbsp;an&nbsp;850/860.&nbsp;<br />These&nbsp;devices&nbsp;are&nbsp;all&nbsp;covered&nbsp;in&nbsp;the&nbsp;MontaVista&nbsp;kernel.&nbsp;<br />823&nbsp;<br />See&nbsp;the&nbsp;823&nbsp;Engineer's&nbsp;Toolbox&nbsp;at:&nbsp;<a href="http://www.motorola.com/SPS/ADC/pps/subpg">http://www.motorola.com/SPS/ADC/pps/subpg</a>&nbsp;<br />s/etoolbox/823/index.html&nbsp;<br />850/855/860&nbsp;<br /><a href="http://www.motorola.com/SPS/RISC/cgi-bin/ncsp/ncsp.cgi">http://www.motorola.com/SPS/RISC/cgi-bin/ncsp/ncsp.cgi</a>&nbsp;<br />For&nbsp;non-Linux-specific&nbsp;technical&nbsp;FAQ's,&nbsp;see:&nbsp;<a href="http://www.mot.com/SPS/RISC/net">http://www.mot.com/SPS/RISC/net</a>&nbsp;<br />comm/support/&nbsp;and&nbsp;especially:&nbsp;<a href="http://www.mot.com/SPS/RISC/netcomm/support/se">http://www.mot.com/SPS/RISC/netcomm/support/se</a>&nbsp;<br />archdb.html&nbsp;<br />603e&nbsp;<br />See:&nbsp;<a href="ftp://vlab1.iram.es/pub/linux-2.2/">ftp://vlab1.iram.es/pub/linux-2.2/</a>&nbsp;<br />Motorola&nbsp;82xx&nbsp;<br />See&nbsp;<a href="http://www.mvista.com/.">http://www.mvista.com/.</a>&nbsp;<br />8240&nbsp;<br />See&nbsp;<a href="ftp://ftp.mvista.com/pub/Area51/sandpoint-8240.">ftp://ftp.mvista.com/pub/Area51/sandpoint-8240.</a>&nbsp;<br />8260&nbsp;<br />See:&nbsp;<a href="http://lists.linuxppc.org/listarcs/linuxppc-embedded/200002/msg00123.ht">http://lists.linuxppc.org/listarcs/linuxppc-embedded/200002/msg00123.ht</a>&nbsp;<br />ml&nbsp;and&nbsp;<a href="http://lists.linuxppc.org/listarcs/linuxppc-embedded/200008/msg00107.">http://lists.linuxppc.org/listarcs/linuxppc-embedded/200008/msg00107.</a>&nbsp;<br />html&nbsp;<br />AltiVec&nbsp;<br />AltiVec&nbsp;is&nbsp;Motorola's&nbsp;answer&nbsp;to&nbsp;Intel's&nbsp;MMX.&nbsp;See&nbsp;<a href="http://www.altivec.com/.">http://www.altivec.com/.</a>&nbsp;<br />See&nbsp;<a href="ftp://ftp.mvista.com/pub/Area51/ppc-altivec.">ftp://ftp.mvista.com/pub/Area51/ppc-altivec.</a>&nbsp;<br />3.2&nbsp;RAM&nbsp;and&nbsp;ROM&nbsp;space&nbsp;<br />Linux&nbsp;has&nbsp;a&nbsp;slightly&nbsp;larger&nbsp;memory&nbsp;footprint&nbsp;than&nbsp;most&nbsp;conventional&nbsp;embedded&nbsp;<br />&nbsp;operating&nbsp;systems&nbsp;when&nbsp;configured&nbsp;with&nbsp;equivalent&nbsp;options.&nbsp;This&nbsp;is&nbsp;the&nbsp;pric&nbsp;<br />e&nbsp;you&nbsp;pay&nbsp;to&nbsp;leverage&nbsp;the&nbsp;advantages&nbsp;of&nbsp;its&nbsp;enormous&nbsp;desktop&nbsp;user&nbsp;base,&nbsp;and&nbsp;&nbsp;<br />being&nbsp;able&nbsp;to&nbsp;share&nbsp;a&nbsp;common&nbsp;desktop&nbsp;and&nbsp;embedded&nbsp;environment.&nbsp;For&nbsp;most&nbsp;appl&nbsp;<br />ications&nbsp;the&nbsp;difference&nbsp;is&nbsp;insignificant,&nbsp;but&nbsp;if&nbsp;every&nbsp;last&nbsp;byte&nbsp;counts&nbsp;in&nbsp;y&nbsp;<br />our&nbsp;application,&nbsp;you&nbsp;might&nbsp;want&nbsp;to&nbsp;consider&nbsp;RTEMs&nbsp;or&nbsp;eCos&nbsp;instead.&nbsp;<br />Beware&nbsp;that&nbsp;commercial&nbsp;embedded&nbsp;operating&nbsp;system&nbsp;vendors&nbsp;often&nbsp;make&nbsp;meaningl&nbsp;<br />ess&nbsp;claims&nbsp;regarding&nbsp;the&nbsp;footprint&nbsp;of&nbsp;their&nbsp;micro-kernel,&nbsp;and&nbsp;the&nbsp;total&nbsp;memo&nbsp;<br />ry&nbsp;footprint&nbsp;(and&nbsp;often&nbsp;the&nbsp;royalties&nbsp;payable)&nbsp;increases&nbsp;substantially&nbsp;once&nbsp;&nbsp;<br />all&nbsp;the&nbsp;optional&nbsp;packages&nbsp;needed&nbsp;to&nbsp;provide&nbsp;the&nbsp;required&nbsp;functionality&nbsp;for&nbsp;a&nbsp;<br />&nbsp;typical&nbsp;networked&nbsp;device&nbsp;are&nbsp;included.&nbsp;Work&nbsp;out&nbsp;what&nbsp;functionality&nbsp;you&nbsp;need&nbsp;<br />&nbsp;before&nbsp;attempting&nbsp;to&nbsp;make&nbsp;valid&nbsp;comparisons.&nbsp;<br />For&nbsp;good&nbsp;architectural&nbsp;reasons,&nbsp;Linux&nbsp;isn't&nbsp;a&nbsp;micro-kernel.&nbsp;However,&nbsp;it&nbsp;does&nbsp;<br />&nbsp;allow&nbsp;large&nbsp;chunks&nbsp;of&nbsp;code&nbsp;to&nbsp;be&nbsp;removed&nbsp;easily&nbsp;at&nbsp;configuration&nbsp;time.&nbsp;In&nbsp;p&nbsp;<br />ractice&nbsp;the&nbsp;architectural&nbsp;distinction&nbsp;between&nbsp;micro&nbsp;and&nbsp;monolithic&nbsp;kernels&nbsp;m&nbsp;<br />akes&nbsp;little&nbsp;difference&nbsp;to&nbsp;total&nbsp;memory&nbsp;requirements&nbsp;of&nbsp;the&nbsp;overall&nbsp;system.&nbsp;<br />Minimum&nbsp;memory&nbsp;requirement&nbsp;when&nbsp;using&nbsp;an&nbsp;initrd&nbsp;based&nbsp;root&nbsp;filesystem&nbsp;is&nbsp;gen&nbsp;<br />erally&nbsp;2&nbsp;MB&nbsp;of&nbsp;flash&nbsp;ROM&nbsp;and&nbsp;8&nbsp;MB&nbsp;of&nbsp;RAM,&nbsp;and&nbsp;here's&nbsp;what&nbsp;you&nbsp;can&nbsp;expect&nbsp;to&nbsp;&nbsp;<br />fit&nbsp;in:&nbsp;<br />8xxROM&nbsp;Monitor&nbsp;<br />Linux-2.2.13&nbsp;kernel&nbsp;<br />minimal&nbsp;compressed&nbsp;initrd&nbsp;root&nbsp;filesystem&nbsp;with&nbsp;/dev,&nbsp;/etc,&nbsp;/var&nbsp;etc.&nbsp;<br />glibc-2.1.3&nbsp;Shared&nbsp;C&nbsp;library,&nbsp;including&nbsp;pthreads&nbsp;support.&nbsp;<br />inetd&nbsp;Internet&nbsp;server&nbsp;<br />ftpd&nbsp;FTP&nbsp;server&nbsp;(for&nbsp;field&nbsp;flash&nbsp;ROM&nbsp;upgrades)&nbsp;<br />Medium&nbsp;sized&nbsp;Embedded&nbsp;C++&nbsp;application&nbsp;(&nbsp;200&nbsp;Kb)&nbsp;<br />This&nbsp;is&nbsp;the&nbsp;most&nbsp;common&nbsp;configuration&nbsp;because&nbsp;it&nbsp;attempts&nbsp;to&nbsp;minimize&nbsp;ROM&nbsp;sp&nbsp;<br />ace&nbsp;at&nbsp;the&nbsp;expense&nbsp;of&nbsp;RAM,&nbsp;since&nbsp;ROM&nbsp;is&nbsp;generally&nbsp;more&nbsp;expensive.&nbsp;However,&nbsp;y&nbsp;<br />ou&nbsp;can&nbsp;trade&nbsp;off&nbsp;ROM&nbsp;space&nbsp;to&nbsp;reduce&nbsp;RAM&nbsp;usage&nbsp;by&nbsp;using&nbsp;a&nbsp;compressed&nbsp;flash&nbsp;f&nbsp;<br />ile&nbsp;system&nbsp;and/or&nbsp;running&nbsp;the&nbsp;kernel&nbsp;directly&nbsp;from&nbsp;ROM.&nbsp;Both&nbsp;these&nbsp;options&nbsp;a&nbsp;<br />re&nbsp;more&nbsp;difficult,&nbsp;but&nbsp;have&nbsp;been&nbsp;successfully&nbsp;deployed&nbsp;and&nbsp;discussed&nbsp;on&nbsp;the&nbsp;&nbsp;<br />mailing&nbsp;list.&nbsp;<br />3.3&nbsp;Commercially&nbsp;available&nbsp;boards&nbsp;<br />There&nbsp;are&nbsp;many&nbsp;off-the-shelf&nbsp;options&nbsp;including&nbsp;systems&nbsp;from&nbsp;Motorola&nbsp;and&nbsp;oth&nbsp;<br />er&nbsp;parties.&nbsp;If&nbsp;you're&nbsp;planning&nbsp;on&nbsp;building&nbsp;your&nbsp;own&nbsp;custom&nbsp;hardware,&nbsp;conside&nbsp;<br />r&nbsp;using&nbsp;one&nbsp;of&nbsp;the&nbsp;Single&nbsp;Board&nbsp;Computer&nbsp;systems&nbsp;listed&nbsp;below&nbsp;instead.&nbsp;You&nbsp;m&nbsp;<br />ay&nbsp;get&nbsp;by&nbsp;with&nbsp;just&nbsp;a&nbsp;custom&nbsp;daughter&nbsp;card,&nbsp;or&nbsp;may&nbsp;not&nbsp;need&nbsp;to&nbsp;do&nbsp;any&nbsp;hardwa&nbsp;<br />re&nbsp;of&nbsp;your&nbsp;own&nbsp;at&nbsp;all.&nbsp;<br />All&nbsp;the&nbsp;boards&nbsp;listed&nbsp;below&nbsp;are&nbsp;known&nbsp;to&nbsp;run&nbsp;Linux,&nbsp;although&nbsp;the&nbsp;degree&nbsp;of&nbsp;s&nbsp;<br />upport&nbsp;can&nbsp;vary.&nbsp;Mention&nbsp;to&nbsp;the&nbsp;vendor&nbsp;that&nbsp;you&nbsp;want&nbsp;to&nbsp;run&nbsp;Linux&nbsp;on&nbsp;the&nbsp;boa&nbsp;<br />rd,&nbsp;and&nbsp;they&nbsp;should&nbsp;be&nbsp;able&nbsp;to&nbsp;point&nbsp;you&nbsp;to&nbsp;the&nbsp;relevant&nbsp;files&nbsp;you&nbsp;need.&nbsp;The&nbsp;<br />&nbsp;best&nbsp;supported&nbsp;boards&nbsp;are&nbsp;supported&nbsp;directly&nbsp;in&nbsp;the&nbsp;main&nbsp;kernel&nbsp;development&nbsp;<br />&nbsp;tree,&nbsp;which&nbsp;is&nbsp;most&nbsp;evident&nbsp;by&nbsp;having&nbsp;a&nbsp;dedicated&nbsp;_MACH_...&nbsp;constant&nbsp;alread&nbsp;<br />y&nbsp;assigned&nbsp;in&nbsp;include/asm-ppc/processor.h.&nbsp;<br />If&nbsp;you&nbsp;still&nbsp;think&nbsp;you&nbsp;want&nbsp;to&nbsp;do&nbsp;a&nbsp;full&nbsp;custom&nbsp;design,&nbsp;pick&nbsp;a&nbsp;board&nbsp;from&nbsp;on&nbsp;<br />e&nbsp;of&nbsp;the&nbsp;following&nbsp;sources&nbsp;with&nbsp;the&nbsp;closest&nbsp;feature&nbsp;match&nbsp;to&nbsp;what&nbsp;you&nbsp;plan&nbsp;t&nbsp;<br />
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