Change and compile wifi driver on android Get

Change and compile wifi driver on android

Get kernel • cd ~/Android • git clone git: //android. git. kernel. org/kernel/msm. git kernel-nexus. One • # the last parameter, nexus. One is your choice. It is the destination directory

List branches and get the branch you want • • #--- Listing all available branches cd kernel-nexus git branch -a # find kernel that matches the phones. . – • • see setting -> about phone -> kernel version #--- Selecting the desired branch. # Assume that one of branch is "remotes/origin/android-msm-2. 6. 32 nexusonec" #git checkout --track -b android-msm-2. 6. 29 -nexusone origin/archive/android-msm-2. 6. 29 -nexusone git checkout --track -b android-msm-2. 6. 32 origin/archive/android-msm 2. 6. 32

Compile kernel • Make config file – – • adb pull /proc/config. gz Move to kernel-nexus. One directory gunzip config. gz mv config Make armmake – – Open new file called armmake Put the follow two lines • • PATH=$PATH: /usr/Android/source/prebuilt/linux-x 86/toolchain/arm-eabi-4. 3. 1/bin make ARCH=arm CROSS_COMPILE=arm-eabi- $1 – Double check that the path is correct. • The arm compiler is part of the ndk – Make armmake executable • Compile kernel (and everything else) –. /armmake • This might take a long time, especially the first time you run it

Driver version • The wifi driver is – kernel-nexus. One/drivers/net/wireless/bcm 4329. ko • The driver should be – /system/lib/modules/bcm 4329. ko • Make a backup to current driver –. /adb pull /system/lib/modules/bcm 4329. ko. old – Do not skip this step! • Move driver – Remount system parition • adb shell mount -o remount rw /system –. /adb push /usr/Android/source/kernelnexus. One/drivers/net/wireless/bcm 4329. ko /system/lib/modules/bcm 4329. ko • Restart wifi – Doesn’t work!!!

Fixing driver version • • The driver version must match the kernel version Check versions – Check old version of driver (if you didn’t it up, this step would be difficult) • at command prompt, type – – • At the command prompts, type – • • These two kernel versions do not match. Get the correct kernel version, or Make the versions stored in the string the same • We follow this approach Find and edit kernel-nexus. One/scripts/setlocalversion file – Step 1 • Make – • • – echo "$atag" | awk -F- '{printf("-%05 d-%s", $(NF-1), $(NF))}' Into – echo "$atag" | awk -F- '{printf("-XXXX")}' Where XXXX is the correct version Step 2 • Make – • printf '%s' –dirty Into – • • • Strings bcm 4329. ko | grep magic Fixes – – • strings bcm 4329. ko. old | grep magic The output is the kernel version printf '' –dirty Save and recompile When done, recheck if versions match Move driver and check that wifi works

new driver • Let’s print information about received frames to kernel messages • Edit kernel-nexus. One/drivers/net/wireless/bcm 4329/dhd_sdio. c • Search for function – dhdsdio_readframes • Add variables – struct sk_buff *Tmp. Pkt; – uchar *HW_header_p; • In the same function, search for – /* Fill in packet len and prio, deliver upward */ – Just above, add • • Tmp. Pkt = (struct sk_buff *)pkt; HW_header_p = (uchar *)Tmp. Pkt->data;

• • • Just before /* Unlock during rx call */, add { uchar *A = HW_header_p; • printk(“HW : %d %dn", A[0], A[1], A[2], A[3]); printk(“SW : seq=%d chan=%d %d doff=%d %d txmax=%d %d %dn", A[4], A[5], A[6], A[7], A[8], A[9], A[10], A[11], A[12], A[13]); printk(“BDC : fl=%d pri=%d fl=%d rssi=%dn", A[14], A[15], A[16], A[17]-256); printk(“MAC : DA=%02 x %02 x SA=%02 x %02 x proto=%02 xn", A[18], A[19], A[20], A[21], A[22], A[23], A[24], A[25], A[26], A[27], A[28], A[29], A[30], A[31]); printk(“MSDU : %02 x %02 x %02 xn", A[32], A[33], A[34], A[35], A[36], A[37], A[38], A[39], A[40], A[41]); } • • • Save and recompile, move driver, restart wifi. Connect to access point. In adb shell, cat /proc/kmsg Observe info being printed out • • •

Sk_buff • • • • • • /** 261 * struct sk_buff - socket buffer 262 * @next: Next buffer in list 263 * @prev: Previous buffer in list 264 * @sk: Socket we are owned by 265 * @tstamp: Time we arrived 266 * @dev: Device we arrived on/are leaving by 267 * @transport_header: Transport layer header 268 * @network_header: Network layer header 269 * @mac_header: Link layer header 270 * @_skb_refdst: destination entry (with norefcount bit) 271 * @sp: the security path, used for xfrm 272 * @cb: Control buffer. Free for use by every layer. Put private vars here 273 * @len: Length of actual data 274 * @data_len: Data length 275 * @mac_len: Length of link layer header 276 * @hdr_len: writable header length of cloned skb 277 * @csum: Checksum (must include start/offset pair) 278 * @csum_start: Offset from skb->head where checksumming should start 279 * @csum_offset: Offset from csum_start where checksum should be stored 280 * @local_df: allow local fragmentation 281 * @cloned: Head may be cloned (check refcnt to be sure) 282 * @nohdr: Payload reference only, must not modify header 283 * @pkt_type: Packet class 284 * @fclone: skbuff clone status • • • • • • • 287 * @users: User count - see {datagram, tcp}. c 288 * @protocol: Packet protocol from driver 289 * @truesize: Buffer size 290 * @head: Head of buffer 291 * @data: Data head pointer 292 * @tail: Tail pointer 293 * @end: End pointer 294 * @destructor: Destruct function 295 * @mark: Generic packet mark 296 * @nfct: Associated connection, if any 297 * @ipvs_property: skbuff is owned by ipvs 298 * @peeked: this packet has been seen already, so stats have been 299 * done for it, don't do them again 300 * @nf_trace: netfilter packet trace flag 301 * @nfctinfo: Relationship of this skb to the connection 302 * @nfct_reasm: netfilter conntrack re-assembly pointer 303 * @nf_bridge: Saved data about a bridged frame - see br_netfilter. c 304 * @skb_iif: ifindex of device we arrived on 305 * @rxhash: the packet hash computed on receive 306 * @queue_mapping: Queue mapping for multiqueue devices 307 * @tc_index: Traffic control index 308 * @tc_verd: traffic control verdict 309 * @ndisc_nodetype: router type (from link layer) 310 * @dma_cookie: a cookie to one of several possible DMA operations 311 * done by skb DMA functions 312 * @secmark: security marking 313 * @vlan_tci: vlan tag control information

Socket buffer (skb) data structure len head data tail end

Functions skb_push(skb, s) len@ s head data@, # tail data moves end Tail is fixed @ : changed # : returned skb_pull(skb, s) len@ s head data@, # tail end

Functions skb_put(skb, s) len@ s head @ : changed # : returned data tail# tail@ end tail moves

Functions skb_headroom(skb) s# head len data tail end # : returned skb_tailroom(skb, s) s# len head data tail end

Functions skb_reserve(skb, s) len head data tail len s head end data@ shifted tail@ end

Functions skb_set_mac_header(skb, s) len s head data mac_header@ tail end skb_reset_mac_header(skb) mac_header@ len head data Mac header points to the beginning of the data

Functions skb_mac_header(skb) mac_header# len head data tail The pattern for network, transport layers is similar end