Re: [Qemu-devel] arm: semihosting: Preliminary AArch64 support

[Liviu Ionescu]

> On 30 Mar 2015, at 14:44, Leon Alrae <address@hidden> wrote:
> 
> ... QEMU parser doesn't seem to support the same sub-argument used multiple
> times (always the last value is used):
> -semihosting-config arg="argument 1",arg="argument 2",arg="argument 3"

yes, unfortunately it is not supported.

please note that the actual code cannot pass the full path of the executable as 
argv[0], because it may be way too long, and semihosting applications usually 
have a tiny buffer to process args.

this is the reason why my code requires passing the entire command line, 
starting with argv[0]. this is also in line with other debugging tools, like 
the SEGGER J-Link GDB Server.

> I may look into it to see how much is missing to make it work.

ok, please do, but last year, when we analysed several options, altering the 
parser was considered too risky.

> The reason I chose "arg" is because it naturally translates into argv[]
> for the guest program. As far as "cmdline" option goes -- wouldn't "arg"
> be more flexible so that you could use it to assemble cmdline?

if you manage to parse multiple sub-arguments with the same name, arg is 
probably ok, but for the entire line I would vote for "cmdline=".

my changes are available from git://git.code.sf.net/p/gnuarmeclipse/qemu, the 
gnuarmeclipse-dev branch (work in progress).

btw, defining an array of strings is not very useful in this case, since the 
semihosting api does not allow to pass it as array, and the strings must be 
concatenated into a single string anyway (and parsed back inside the 
application). 


regards,

Liviu