@@ -139,6 +139,7 @@ struct imx_fuse {
#if defined(CONFIG_IMX_HAB)
extern struct imx_fuse const imx_sec_config_fuse;
+extern struct imx_fuse const imx_field_return_fuse;
#endif
/*Function prototype description*/
@@ -26,6 +26,14 @@ DECLARE_GLOBAL_DATA_PTR;
#define IS_HAB_ENABLED_BIT \
(is_soc_type(MXC_SOC_MX7ULP) ? 0x80000000 : \
((is_soc_type(MXC_SOC_MX7) || is_soc_type(MXC_SOC_IMX8M)) ? 0x2000000 : 0x2))
+#define FIELD_RETURN_FUSE_MASK \
+ (is_imx8mp() ? 0xFFFFFFFF : 0x00000001)
+/*
+ * The fuse pattern for i.MX8M Plus is 0x28001401, but bit 2 is already set from factory.
+ * This means when field return is set, the fuse word value reads 0x28001405
+ */
+#define FIELD_RETURN_PATTERN \
+ (is_imx8mp() ? 0x28001405 : 0x00000001)
#ifdef CONFIG_MX7ULP
#define HAB_M4_PERSISTENT_START ((soc_rev() >= CHIP_REV_2_0) ? 0x20008040 : \
@@ -870,18 +878,30 @@ static int validate_ivt(struct ivt *ivt_initial)
bool imx_hab_is_enabled(void)
{
- struct imx_fuse *fuse =
+ struct imx_fuse *sec_config =
(struct imx_fuse *)&imx_sec_config_fuse;
+ struct imx_fuse *field_return =
+ (struct imx_fuse *)&imx_field_return_fuse;
uint32_t reg;
+ bool is_enabled;
int ret;
- ret = fuse_read(fuse->bank, fuse->word, ®);
+ ret = fuse_read(sec_config->bank, sec_config->word, ®);
if (ret) {
- puts("\nSecure boot fuse read error\n");
+ puts("Secure boot fuse read error\n");
return ret;
}
+ is_enabled = reg & IS_HAB_ENABLED_BIT;
+ if (is_enabled) {
+ ret = fuse_read(field_return->bank, field_return->word, ®);
+ if (ret) {
+ puts("Field return fuse read error\n");
+ return ret;
+ }
+ is_enabled = (reg & FIELD_RETURN_FUSE_MASK) != FIELD_RETURN_PATTERN;
+ }
- return (reg & IS_HAB_ENABLED_BIT) == IS_HAB_ENABLED_BIT;
+ return is_enabled;
}
int imx_hab_authenticate_image(uint32_t ddr_start, uint32_t image_size,
@@ -41,6 +41,11 @@ struct imx_fuse const imx_sec_config_fuse = {
.bank = 1,
.word = 3,
};
+
+struct imx_fuse const imx_field_return_fuse = {
+ .bank = 8,
+ .word = 3,
+};
#endif
int timer_init(void)
@@ -55,6 +55,11 @@ struct imx_fuse const imx_sec_config_fuse = {
.bank = 0,
.word = 6,
};
+
+struct imx_fuse const imx_field_return_fuse = {
+ .bank = 5,
+ .word = 6,
+};
#endif
u32 get_nr_cpus(void)
@@ -131,6 +131,11 @@ struct imx_fuse const imx_sec_config_fuse = {
.bank = 1,
.word = 3,
};
+
+struct imx_fuse const imx_field_return_fuse = {
+ .bank = 8,
+ .word = 3,
+};
#endif
static bool is_mx7d(void)
@@ -42,6 +42,11 @@ struct imx_fuse const imx_sec_config_fuse = {
.bank = 29,
.word = 6,
};
+
+struct imx_fuse const imx_field_return_fuse = {
+ .bank = 9,
+ .word = 6,
+};
#endif
#define ROM_VERSION_ADDR 0x80
The decision on whether HAB is enabled is solely based on the SEC_CONFIG fuse. The HAB FIELD_RETURN feature is able to permanently disable HAB on a CPU, after which it is able to boot unsigned firmware. U-Boot however does not take into account the FIELD_RETURN mode, and refuses to boot unsigned software when the feature is enabled. Also take the FIELD_RETURN fuse into account when deciding whether HAB is enabled. When The FIELD_RETURN fuse is blown, HAB is not enabled. Tested on i.MX8M Mini, i.MX8M Plus, i.MX8M Nano and i.MX6ULL Signed-off-by: Paul Geurts <paul.geurts@prodrive-technologies.com> --- arch/arm/include/asm/mach-imx/hab.h | 1 + arch/arm/mach-imx/hab.c | 28 ++++++++++++++++++++++++---- arch/arm/mach-imx/imx8m/soc.c | 5 +++++ arch/arm/mach-imx/mx6/soc.c | 5 +++++ arch/arm/mach-imx/mx7/soc.c | 5 +++++ arch/arm/mach-imx/mx7ulp/soc.c | 5 +++++ 6 files changed, 45 insertions(+), 4 deletions(-)