Architecturally the CCR is not byte-accessible. The v7M Arm ARM defines
in B3.1.1 "General rules for PPB register accesses" that unless
otherwise stated, register support word accesses only, and the CCR
register definition does not say that byte access is supported. This is
true also in v8M, where the CCR register definition explicitly marks
halfword and byte accesses to CCR as UNPREDICTABLE.
So this looks like buggy guest code to me...
** Changed in: qemu
Status: New => Incomplete
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1863526
Title:
NVIC CCR register not 8-bit accessible using Cortex-M4
Status in QEMU:
Incomplete
Bug description:
Head at commit b29c3e23f64938.
Running with '-d unimp,guest_errors -trace nvic\*' I get:
[email protected]:nvic_sysreg_read NVIC sysreg read addr 0xd88 data
0xf00000 size 4
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd88 data
0xf00000 size 4
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd08 data
0x4200 size 4
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd15 data
0x0 size 1
NVIC: Bad write of size 1 at offset 0xd15
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd16 data
0x0 size 1
NVIC: Bad write of size 1 at offset 0xd16
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd17 data
0x0 size 1
NVIC: Bad write of size 1 at offset 0xd17
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd18 data
0x0 size 1
[email protected]:nvic_set_prio NVIC set irq 4 secure-bank 0 priority 0
[email protected]:nvic_recompute_state NVIC state recomputed:
vectpending 0 vectpending_prio 256 exception_prio 256
[email protected]:nvic_irq_update NVIC vectpending 0 pending prio 256
exception_prio 256: setting irq line to 0
[email protected]:nvic_sysreg_write NVIC sysreg write addr 0xd19 data
0x0 size 1
[email protected]:nvic_set_prio NVIC set irq 5 secure-bank 0 priority 0
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1863526/+subscriptions
