Re: [Qemu-devel] [PULL 00/31] Misc changes for 2016-05-27

[Peter Maydell]

On 27 May 2016 at 13:53, Peter Maydell <address@hidden> wrote:
> On 27 May 2016 at 11:06, Paolo Bonzini <address@hidden> wrote:
>> The following changes since commit b75536c9fa742f887304769d0608557bb8e3a27f:
>>
>>   blockjob: Remove BlockJob.bs (2016-05-25 19:04:21 +0200)
>>
>> are available in the git repository at:
>>
>>   git://github.com/bonzini/qemu.git tags/for-upstream
>>
>> for you to fetch changes up to 7052033834d4c2d7ade147cf5b045be6eaf07113:
>>
>>   exec: hide mr->ram_addr from qemu_get_ram_ptr users (2016-05-27 11:55:23 
>> +0200)
>>
>> ----------------------------------------------------------------
>> * docs/atomics fixes and atomic_rcu_* optimization (Emilio)
>> * NBD bugfix (Eric)
>> * Memory fixes and cleanups (Paolo, Paul)
>> * scsi-block support for SCSI status, including persistent
>>   reservations (Paolo)
>> * linuxboot support for fw_cfg DMA (Marc, Richard Jones)
>> * kvm_stat moves to the Linux repository
>> * SCSI bug fixes (Peter, Prasad)
>> * Killing qemu_char_get_next_serial, non-ARM parts (Xiaoqiang)
>
> Hi; this fails to build for w32:
>
>   CC    optionrom/linuxboot_dma.o
>   Building optionrom/linuxboot_dma.img
> linuxboot_dma.o:linuxboot_dma.c:(.text+0x57): undefined reference to
> `load_kernel'

With V=1:

i686-w64-mingw32-ld -m i386pe -Ttext 0 -e _start -s -o
linuxboot_dma.img linuxboot_dma.o
linuxboot_dma.o:linuxboot_dma.c:(.text+0x57): undefined reference to
`load_kernel'

Building an image for the target using our host compiler seems like
an odd choice, but the makefile obviously intends to support it
since it has specific ifdef CONFIG_WIN32 code to adjust the linker
command line.

I suspect this is a mismatch between the symbol the native asm is
using and the one that the C compiler wants:

$ nm build/w32-new/pc-bios/optionrom/linuxboot_dma.o |grep load_kernel
000005dd T _load_kernel
         U load_kernel

since name mangling rules are different for Linux and Windows ABIs.

thanks
-- PMM