ARM CPUs fetch instructions in little-endian. smpboot[] encoded instructions are written in little-endian.
We call tswap32() on the array. tswap32 function swap a 32-bit value if the target endianness doesn't match the host one. Otherwise it is a NOP. * On a little-endian host, the array is stored as it. tswap32() is a NOP, and the vCPU fetches the instructions as it, in little-endian. * On a big-endian host, the array is stored as it. tswap32() swap the instructions to little-endian, and the vCPU fetches the instructions as it, in little-endian. Using tswap() on system emulation is a bit odd: while the target particularities might change the system emulation, the host ones (such its endianness) shouldn't interfere. We can simplify by using const_le32() to always store the instructions in the array in little-endian, removing the need for the dubious tswap(). Two boards which weren't swapping (aspeed and raspi) are fixed. Tested running ARM avocado tests on x86_64 and s390x. Philippe Mathieu-Daudé (6): hw/arm/aspeed: Fix smpboot[] on big-endian hosts hw/arm/raspi: Fix smpboot[] on big-endian hosts hw/arm/exynos4210: Remove tswap32() calls and constify smpboot[] hw/arm/npcm7xx: Remove tswap32() calls and constify smpboot[] hw/arm/xilinx_zynq: Remove tswap32() calls and constify smpboot[] hw/arm/boot: Remove tswap32() calls and constify board_setup_blob[] hw/arm/aspeed.c | 28 ++++++++++++------------ hw/arm/boot.c | 52 +++++++++++++++++++------------------------- hw/arm/exynos4210.c | 48 ++++++++++++++++++---------------------- hw/arm/npcm7xx.c | 49 +++++++++++++++++------------------------ hw/arm/raspi.c | 46 +++++++++++++++++++-------------------- hw/arm/xilinx_zynq.c | 27 ++++++++++------------- 6 files changed, 112 insertions(+), 138 deletions(-) -- 2.38.1
