Public bug reported:
If FPU is enabled by writing to CPACR, and the code is in the same
translation block as the following VFP code, qemu generates "v7M NOCP
UsageFault".
This can be reproduced with git HEAD (commit
8fe9f1f891eff4e37f82622b7480ee748bf4af74).
The target binary is attached. The qemu command is:
qemu-system-arm -nographic -monitor null -serial null -semihosting -machine
mps2-an505 -cpu cortex-m33 -kernel cpacr_vfp.elf -d
in_asm,int,exec,cpu,cpu_reset,unimp,guest_errors,nochain -D log
If the code is changed a little, so that they are not in the same block,
VFP code can see the effect of CPACR, or -singlestep of qemu has the
same result.
** Affects: qemu
Importance: Undecided
Status: New
** Tags: arm vfp
** Attachment added: "cpacr_vfp.elf"
https://bugs.launchpad.net/bugs/1924669/+attachment/5488612/+files/cpacr_vfp.elf
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https://bugs.launchpad.net/bugs/1924669
Title:
VFP code cannot see CPACR write in the same TB
Status in QEMU:
New
Bug description:
If FPU is enabled by writing to CPACR, and the code is in the same
translation block as the following VFP code, qemu generates "v7M NOCP
UsageFault".
This can be reproduced with git HEAD (commit
8fe9f1f891eff4e37f82622b7480ee748bf4af74).
The target binary is attached. The qemu command is:
qemu-system-arm -nographic -monitor null -serial null -semihosting -machine
mps2-an505 -cpu cortex-m33 -kernel cpacr_vfp.elf -d
in_asm,int,exec,cpu,cpu_reset,unimp,guest_errors,nochain -D log
If the code is changed a little, so that they are not in the same
block, VFP code can see the effect of CPACR, or -singlestep of qemu
has the same result.
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https://bugs.launchpad.net/qemu/+bug/1924669/+subscriptions
