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authorPeter Maydell <peter.maydell@linaro.org>2021-03-18 17:48:23 +0000
committerPeter Maydell <peter.maydell@linaro.org>2021-03-23 11:47:31 +0000
commit75ce72b785a7c9fcb9af2779854142a34825da59 (patch)
tree0713f93030ad23b5d77af9717c2a303a7deb2858
parent1228c4596a0046b3e4e71f62773caa835dfc79df (diff)
target/arm: Make M-profile VTOR loads on reset handle memory aliasing
For Arm M-profile CPUs, on reset the CPU must load its initial PC and SP from a vector table in guest memory. Because we can't guarantee reset ordering, we have to handle the possibility that the ROM blob loader's reset function has not yet run when the CPU resets, in which case the data in an ELF file specified by the user won't be in guest memory to be read yet. We work around the reset ordering problem by checking whether the ROM blob loader has any data for the address where the vector table is, using rom_ptr(). Unfortunately this does not handle the possibility of memory aliasing. For many M-profile boards, memory can be accessed via multiple possible physical addresses; if the board has the vector table at address X but the user's ELF file loads data via a different address Y which is an alias to the same underlying guest RAM then rom_ptr() will not find it. Use the new rom_ptr_for_as() function, which deals with memory aliasing when locating a relevant ROM blob. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20210318174823.18066-6-peter.maydell@linaro.org
-rw-r--r--target/arm/cpu.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index ae04884408..0dd623e590 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -331,7 +331,7 @@ static void arm_cpu_reset(DeviceState *dev)
/* Load the initial SP and PC from offset 0 and 4 in the vector table */
vecbase = env->v7m.vecbase[env->v7m.secure];
- rom = rom_ptr(vecbase, 8);
+ rom = rom_ptr_for_as(s->as, vecbase, 8);
if (rom) {
/* Address zero is covered by ROM which hasn't yet been
* copied into physical memory.