[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v6] Add optionrom compatible with fw_cfg DMA ver
Re: [Qemu-devel] [PATCH v6] Add optionrom compatible with fw_cfg DMA version
Mon, 9 May 2016 23:16:00 +0200
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0
On 05/09/16 18:48, Richard W.M. Jones wrote:
> Actually there's a rather more fundamental problem. In the current
> linuxboot_dma.c we use asm statements at the top and bottom of the
> file (outside any function). The asm statements define the header and
> what I assume is the footer of the file. At any rate, they encode the
> size of the file (the calculation `.byte (_end - _start) / 512').
> Clang just rearranges everything in the file, so the _start and _end
> asm snippets appear together at the beginning of the input to the
> assembler, and nothing works after that.
> So that pretty much screws up the whole project of trying to write an
> option ROM in C.
> Of course we're well outside any standards here. Can we tell clang
> users to use the GCC/pre-compiled option ROMs :-? Any other ideas? I
> don't think I've missed a flag (GCC has -fno-toplevel-reorder, but
> clang 3.8 doesn't ...)
IIRC for a while we used to ship pre-compiled ACPI byte-code, for people
who didn't have "iasl" installed.
We could make this C source file gcc-only, and provide a pre-compiled
assembly source file for those platforms that only have clang.