target: disable armv6m unaligned memory access

[openocd] / src / target / cortex_m.c

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index f992bde4160acdbfd83536d720d8240618a61d98..e4374318aa1afb71a42a97f18cd60c8d356cde8f 100644 (file)
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1570,6 +1570,12 @@ static int cortex_m3_read_memory(struct target *target, uint32_t address,
        struct adiv5_dap *swjdp = &armv7m->dap;
        int retval = ERROR_COMMAND_SYNTAX_ERROR;
 
+       if (armv7m->arm.is_armv6m) {
+               /* armv6m does not handle unaligned memory access */
+               if (((size == 4) && (address & 0x3u)) || ((size == 2) && (address & 0x1u)))
+                       return ERROR_TARGET_UNALIGNED_ACCESS;
+       }
+
        /* cortex_m3 handles unaligned memory access */
        if (count && buffer) {
                switch (size) {
@@ -1595,6 +1601,12 @@ static int cortex_m3_write_memory(struct target *target, uint32_t address,
        struct adiv5_dap *swjdp = &armv7m->dap;
        int retval = ERROR_COMMAND_SYNTAX_ERROR;
 
+       if (armv7m->arm.is_armv6m) {
+               /* armv6m does not handle unaligned memory access */
+               if (((size == 4) && (address & 0x3u)) || ((size == 2) && (address & 0x1u)))
+                       return ERROR_TARGET_UNALIGNED_ACCESS;
+       }
+
        if (count && buffer) {
                switch (size) {
                        case 4:
@@ -1780,9 +1792,13 @@ int cortex_m3_examine(struct target *target)
        struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
        struct armv7m_common *armv7m = target_to_armv7m(target);
 
-       retval = ahbap_debugport_init(swjdp);
-       if (retval != ERROR_OK)
-               return retval;
+       /* stlink shares the examine handler but does not support
+        * all its calls */
+       if (!armv7m->stlink) {
+               retval = ahbap_debugport_init(swjdp);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
 
        if (!target_was_examined(target)) {
                target_set_examined(target);
@@ -1808,6 +1824,9 @@ int cortex_m3_examine(struct target *target)
                                LOG_DEBUG("Cortex-M%d floating point feature FPv4_SP found", i);
                                armv7m->fp_feature = FPv4_SP;
                        }
+               } else if (i == 0) {
+                       /* Cortex-M0 does not support unaligned memory access */
+                       armv7m->arm.is_armv6m = true;
                }
 
                /* NOTE: FPB and DWT are both optional. */