[sw/silicon_creator] Clean up flash disable in shutdown
The flash disable register was originally rw1c but is now rw0c.
Writing 1 to the register does actually work because the reset value
of the register is 5 but writing 0 to the register is cleaner.
Signed-off-by: Michael Munday <mike.munday@lowrisc.org>
diff --git a/sw/device/silicon_creator/lib/shutdown.c b/sw/device/silicon_creator/lib/shutdown.c
index dac24e9..b932df8 100644
--- a/sw/device/silicon_creator/lib/shutdown.c
+++ b/sw/device/silicon_creator/lib/shutdown.c
@@ -294,7 +294,8 @@
SHUTDOWN_FUNC(NO_MODIFIERS, shutdown_flash_kill(void)) {
enum { kBase = TOP_EARLGREY_FLASH_CTRL_CORE_BASE_ADDR };
- abs_mmio_write32(kBase + FLASH_CTRL_DIS_REG_OFFSET, 1);
+ // Setting DIS (rw0c) to a value other than 5 will disable flash permanently.
+ abs_mmio_write32(kBase + FLASH_CTRL_DIS_REG_OFFSET, 0);
}
SHUTDOWN_FUNC(noreturn, shutdown_hang(void)) {
diff --git a/sw/device/silicon_creator/lib/shutdown_unittest.cc b/sw/device/silicon_creator/lib/shutdown_unittest.cc
index bc0f216..19dc487 100644
--- a/sw/device/silicon_creator/lib/shutdown_unittest.cc
+++ b/sw/device/silicon_creator/lib/shutdown_unittest.cc
@@ -605,7 +605,7 @@
TEST_F(ShutdownTest, FlashKill) {
EXPECT_ABS_WRITE32(
- TOP_EARLGREY_FLASH_CTRL_CORE_BASE_ADDR + FLASH_CTRL_DIS_REG_OFFSET, 1);
+ TOP_EARLGREY_FLASH_CTRL_CORE_BASE_ADDR + FLASH_CTRL_DIS_REG_OFFSET, 0);
unmocked_shutdown_flash_kill();
}
