aspeed: sbc: Allow per-machine settings

In order to correctly report secure boot running firmware the values
of certain registers must be set.

We don't yet have documentation from ASPEED on what they mean. The
meaning is inferred from u-boot's use of them.

Introduce properties so the settings can be configured per-machine.

Reviewed-by: Peter Delevoryas <pdel@fb.com>
Tested-by: Peter Delevoryas <pdel@fb.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20220628154740.1117349-4-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/misc/aspeed_sbc.c

@@ -11,6 +11,7 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/error-report.h"
+#include "hw/qdev-properties.h"
 #include "hw/misc/aspeed_sbc.h"
 #include "qapi/error.h"
 #include "migration/vmstate.h"
@@ -19,6 +20,27 @@
 #define R_STATUS        (0x014 / 4)
 #define R_QSR           (0x040 / 4)
 
+/* R_STATUS */
+#define ABR_EN                  BIT(14) /* Mirrors SCU510[11] */
+#define ABR_IMAGE_SOURCE        BIT(13)
+#define SPI_ABR_IMAGE_SOURCE    BIT(12)
+#define SB_CRYPTO_KEY_EXP_DONE  BIT(11)
+#define SB_CRYPTO_BUSY          BIT(10)
+#define OTP_WP_EN               BIT(9)
+#define OTP_ADDR_WP_EN          BIT(8)
+#define LOW_SEC_KEY_EN          BIT(7)
+#define SECURE_BOOT_EN          BIT(6)
+#define UART_BOOT_EN            BIT(5)
+/* bit 4 reserved*/
+#define OTP_CHARGE_PUMP_READY   BIT(3)
+#define OTP_IDLE                BIT(2)
+#define OTP_MEM_IDLE            BIT(1)
+#define OTP_COMPARE_STATUS      BIT(0)
+
+/* QSR */
+#define QSR_RSA_MASK           (0x3 << 12)
+#define QSR_HASH_MASK          (0x3 << 10)
+
 static uint64_t aspeed_sbc_read(void *opaque, hwaddr addr, unsigned int size)
 {
     AspeedSBCState *s = ASPEED_SBC(opaque);
@@ -80,8 +102,17 @@ static void aspeed_sbc_reset(DeviceState *dev)
     memset(s->regs, 0, sizeof(s->regs));
 
     /* Set secure boot enabled with RSA4096_SHA256 and enable eMMC ABR */
-    s->regs[R_STATUS] = 0x000044C6;
-    s->regs[R_QSR] = 0x07C07C89;
+    s->regs[R_STATUS] = OTP_IDLE | OTP_MEM_IDLE;
+
+    if (s->emmc_abr) {
+        s->regs[R_STATUS] &= ABR_EN;
+    }
+
+    if (s->signing_settings) {
+        s->regs[R_STATUS] &= SECURE_BOOT_EN;
+    }
+
+    s->regs[R_QSR] = s->signing_settings;
 }
 
 static void aspeed_sbc_realize(DeviceState *dev, Error **errp)
@@ -105,6 +136,12 @@ static const VMStateDescription vmstate_aspeed_sbc = {
     }
 };
 
+static Property aspeed_sbc_properties[] = {
+    DEFINE_PROP_BOOL("emmc-abr", AspeedSBCState, emmc_abr, 0),
+    DEFINE_PROP_UINT32("signing-settings", AspeedSBCState, signing_settings, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void aspeed_sbc_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -112,6 +149,7 @@ static void aspeed_sbc_class_init(ObjectClass *klass, void *data)
     dc->realize = aspeed_sbc_realize;
     dc->reset = aspeed_sbc_reset;
     dc->vmsd = &vmstate_aspeed_sbc;
+    device_class_set_props(dc, aspeed_sbc_properties);
 }
 
 static const TypeInfo aspeed_sbc_info = {

include/hw/misc/aspeed_sbc.h

@@ -17,9 +17,22 @@ OBJECT_DECLARE_TYPE(AspeedSBCState, AspeedSBCClass, ASPEED_SBC)
 
 #define ASPEED_SBC_NR_REGS (0x93c >> 2)
 
+#define QSR_AES                     BIT(27)
+#define QSR_RSA1024                 (0x0 << 12)
+#define QSR_RSA2048                 (0x1 << 12)
+#define QSR_RSA3072                 (0x2 << 12)
+#define QSR_RSA4096                 (0x3 << 12)
+#define QSR_SHA224                  (0x0 << 10)
+#define QSR_SHA256                  (0x1 << 10)
+#define QSR_SHA384                  (0x2 << 10)
+#define QSR_SHA512                  (0x3 << 10)
+
 struct AspeedSBCState {
     SysBusDevice parent;
 
+    bool emmc_abr;
+    uint32_t signing_settings;
+
     MemoryRegion iomem;
 
     uint32_t regs[ASPEED_SBC_NR_REGS];