h1. AddingADB

First extract the boot.img from the zip
<pre>
$ mkdir temp
$ cd temp 
$ unzip ../replicant-6.0-0004-rc1-maguro.zip
$ file boot.img
boot.img: Android bootimg, kernel, ramdisk, page size: 2048, cmdline (androidboot.hardware=tuna)
</pre>

Then extract the kernel, and initramfs from the boot.img. Also save the infos such as the load address, etc in boot.txt:
<pre>
$ unbootimg --kernel kernel.img --ramdisk ramdisk.cpio.gz -i boot.img | tee boot.txt
total image size:   5619712
kernel size:        4604340
kernel load addr:   0x80008000
ramdisk size:       1009915
ramdisk load addr:  0x81000000
2nd boot size:      0
2nd boot load addr: 0x80f00000
kernel tags addr:   0x80000100
page size:          2048
board:              `'
cmdline:            `androidboot.hardware=tuna'
id:                 9b90141066f527ecd3909d2ab8e383ebd995fd40000
</pre>

Then uncompress the initramfs
<pre>
$ gunzip ramdisk.cpio.gz
$ file ramdisk.cpio 
ramdisk.cpio: ASCII cpio archive (SVR4 with no CRC)
</pre>

Then edit the default.props, we use sed on the raw cpio image for simplicity (we don't have permissions and username to take care of this way):
<pre>
$ sed 's#ro.adb.secure=0#               #' -i ramdisk.cpio
$ sed 's#ro.secure=1#ro.secure=0#' -i ramdisk.cpio
$ sed 's#persist.sys.usb.config=none#persist.sys.usb.config=adb #' -i ramdisk.cpio
</pre>

Then recompress the initramfs
<pre>
$ gzip ramdisk.cpio
</pre>

We then recreate the image with the infos we saved in boot.txt. Note that the base is 0x80000000. The kernel has an offset and will be in 0x80008000:
<pre>
$ mkbootimg --cmdline="androidboot.hardware=tuna" --kernel kernel.img --ramdisk ramdisk.cpio.gz  --base 0x80000000 -o boot_new.img
</pre>

Verify that we got all the arguments right:
<pre>
$ unbootimg -i boot_new.img | tee boot_new.txt
$ diff -u boot.txt boot_new.txt
$ --- boot.txt	2020-02-18 00:39:59.890285634 +0100
+++ boot_new.txt	2020-02-18 00:44:16.208897037 +0100
@@ -1,7 +1,7 @@
 total image size:   5619712
 kernel size:        4604340
 kernel load addr:   0x80008000
-ramdisk size:       1009915
+ramdisk size:       1010280
 ramdisk load addr:  0x81000000
 2nd boot size:      0
 2nd boot load addr: 0x80f00000
@@ -9,4 +9,4 @@
 page size:          2048
 board:              `'
 cmdline:            `androidboot.hardware=tuna'
-id:                 9b90141066f527ecd3909d2ab8e383ebd995fd40000
+id:                 dd37b2ae1e50be62fe5c94b81b85aa56ffea17be000
</pre>

Reflash the image:
<pre>
heimdall flash --boot boot.img --recovery boot.img
</pre>