tendaac1518_httpd.py unicorn.unicorn.UcError: Invalid memory write (UC_ERR_WRITE_UNMAPPED)

[Ryze-T]

I followed the official documentation, used the official example:

https://github.com/qilingframework/qiling/blob/master/examples/tendaac1518_httpd.py

and still got an error :

I suggest that the official write a tutorial about the simulation firmware！！！

[elicn]

I recreated the environment to test it, but I am afraid I am no ARM expert, so I cannot tell exactly what's wrong there.
I did pick up the following, however:

• The /proc/sys/net/ipv4 folder should be created under rootfs
• The /proc/sys/kernel folder should be created under rootfs
• A file named /proc/sys/kernel/core_pattern is created on every run, and should be removed before running again
• The code accesses memory on 0xfffddxxx, which I guess has a special meaning for that particular ARM processor, but I do not know what it is. So I ended up just mapping it with ql.mem.map(0xfffdd000, 0x1000), and it kept running for a while until it crashed with access to page 0, which I suspect is a result of bogus data it read from the afored address. My guess is that zeros were read from the mapped address and then used in a pointer calculation for a further access that failed.

I don't know enough to really fix this.
Perhaps @xwings knows and can help fixing it.

[Ryze-T]

I recreated the environment to test it, but I am afraid I am no ARM expert, so I cannot tell exactly what's wrong there. I did pick up the following, however:

• The /proc/sys/net/ipv4 folder should be created under rootfs
• The /proc/sys/kernel folder should be created under rootfs
• A file named /proc/sys/kernel/core_pattern is created on every run, and should be removed before running again
• The code accesses memory on 0xfffddxxx, which I guess has a special meaning for that particular ARM processor, but I do not know what it is. So I ended up just mapping it with ql.mem.map(0xfffdd000, 0x1000), and it kept running for a while until it crashed with access to page 0, which I suspect is a result of bogus data it read from the afored address. My guess is that zeros were read from the mapped address and then used in a pointer calculation for a further access that failed.

I don't know enough to really fix this. Perhaps @xwings knows and can help fixing it.

Thank you for your help.
And I've tried something similar, but it crashes after a while，I hope this problem will be properly solved.

[xwings]

As far as i remeber, there is some crash when running the binary. What do you trying to achive and which version of Qiling are you running ?

[Ryze-T]

Qiling: lastest
I want to run httpd successfully when I fix the crash

[xwings]

I found and the bug and the fix is in #1249
Please checkout the latest dev version and try