[mask_rom] Do Not Zero Test Area
We avoid zeroing the Test area in RAM, which is used by DV and Verilator
to report information to the simulation environment. This should avoid
spurious failures where we write data that causes the core to halt.
Signed-off-by: Sam Elliott <selliott@lowrisc.org>
diff --git a/sw/device/mask_rom/mask_rom_start.S b/sw/device/mask_rom/mask_rom_start.S
index 8de9ca9..ba5d30d 100644
--- a/sw/device/mask_rom/mask_rom_start.S
+++ b/sw/device/mask_rom/mask_rom_start.S
@@ -205,7 +205,9 @@
// `t0` is the address to start zeroing at.
// `t1` is the address to stop zeroing at.
li t0, TOP_EARLGREY_RAM_MAIN_BASE_ADDR
- li t1, (TOP_EARLGREY_RAM_MAIN_BASE_ADDR + TOP_EARLGREY_RAM_MAIN_SIZE_BYTES)
+ // TODO: Ensure we do zero all of RAM, for the moment we're not zeroing the
+ // test area. https://github.com/lowRISC/opentitan/issues/3619
+ la t1, _test_reserved_start
bgeu t0, t1, sram_zero_end
sram_zero_loop:
// TODO: Unroll loop
