How a plugin image works in newer uboot ?

[mrigendra_chaub]

I have a sabresd board, running with latest android O.

I also have an older code for another imx6qp based board. That board is based on plugin boot and it uses flash_header.S. I am trying to take changes from older code and integrate to the newer one.

Can anyone help me in understanding this,

Previously we used to have one flash_header.S file which used to support plugin booting.

Now same flash_header.S is broken in two files, one is plugin.S and another is mx6_plugin.S.

Can anybody tell me what are the fundamental difference between these two?

Like how and when,

b _start

is called when we use plugin.S and mx6_plugin.S.

When ivt header entries are created?

I see this in mx6_plugin.S

second_ivt_offset: .long (ivt2_header + 0x2C + FLASH_OFFSET)

/*
* The following is the second IVT header plus the second boot data
*/
ivt2_header: .long 0x0
app2_code_jump_v: .long 0x0
reserv3: .long 0x0
dcd2_ptr: .long 0x0
boot_data2_ptr: .long 0x0
self_ptr2: .long 0x0
app_code_csf2: .long 0x0
reserv4: .long 0x0
boot_data2: .long 0x0
image_len2: .long 0x0
plugin2: .long 0x0

No values are given, so when values are given? in flash_header.S all values for ivt headers were hardcoded.

Also in the generated linker u-boot.lds I don't see any flashheader section.

[diegoadrian]

Hello, 

I do not know if you are still having a problem. 

In the newer Android releases is not necessary for what you mentioned above, since the u-boot image is created with all that Android needs to boot. If you want to create the u-boot image separately you can see the section 3.3 of the Android User Guide. 

Hope this can help you.

Best Regards,

Diego.