Merge "fix(imx8mq): fix compilation with gcc >= 12.x" into integration
diff --git a/plat/imx/imx8m/imx8mq/imx8mq_bl31_setup.c b/plat/imx/imx8m/imx8mq/imx8mq_bl31_setup.c
index 661f8e2..7065a65 100644
--- a/plat/imx/imx8m/imx8mq/imx8mq_bl31_setup.c
+++ b/plat/imx/imx8m/imx8mq/imx8mq_bl31_setup.c
@@ -30,6 +30,20 @@
#define TRUSTY_PARAMS_LEN_BYTES (4096*2)
+/*
+ * Avoid the pointer dereference of the canonical mmio_read_8() implementation.
+ * This prevents the compiler from mis-interpreting the MMIO access as an
+ * illegal memory access to a very low address (the IMX ROM is mapped at 0).
+ */
+static uint8_t mmio_read_8_ldrb(uintptr_t address)
+{
+ uint8_t reg;
+
+ __asm__ volatile ("ldrb %w0, [%1]" : "=r" (reg) : "r" (address));
+
+ return reg;
+}
+
static const mmap_region_t imx_mmap[] = {
MAP_REGION_FLAT(GPV_BASE, GPV_SIZE, MT_DEVICE | MT_RW), /* GPV map */
MAP_REGION_FLAT(IMX_ROM_BASE, IMX_ROM_SIZE, MT_MEMORY | MT_RO), /* ROM map */
@@ -70,11 +84,11 @@
uint32_t ocotp_val;
imx_soc_revision = mmio_read_32(IMX_ANAMIX_BASE + ANAMIX_DIGPROG);
- rom_version = mmio_read_8(IMX_ROM_BASE + ROM_SOC_INFO_A0);
+ rom_version = mmio_read_8_ldrb(IMX_ROM_BASE + ROM_SOC_INFO_A0);
if (rom_version == 0x10)
return;
- rom_version = mmio_read_8(IMX_ROM_BASE + ROM_SOC_INFO_B0);
+ rom_version = mmio_read_8_ldrb(IMX_ROM_BASE + ROM_SOC_INFO_B0);
if (rom_version == 0x20) {
imx_soc_revision &= ~0xff;
imx_soc_revision |= rom_version;