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authorJonathan Neuschäfer <j.neuschaefer@gmx.net>2016-08-22 19:37:15 +0200
committerRonald G. Minnich <rminnich@gmail.com>2016-08-23 23:43:24 +0200
commitb6648cd888f1ba8e0e81c59f296028ba831c6eae (patch)
tree682cfc84a95cb4146261ee2a754f7390c84f3bae
parent85b1aadcc1f0cec7eef73a527c5131fb3b1c2f95 (diff)
arch/riscv: Fix unaligned memory access emulation
Change-Id: I06c6493355f25f3780f75e345c517b434912696f Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-on: https://review.coreboot.org/16261 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
-rw-r--r--src/arch/riscv/trap_handler.c32
1 files changed, 20 insertions, 12 deletions
diff --git a/src/arch/riscv/trap_handler.c b/src/arch/riscv/trap_handler.c
index 9f3f07f830..d8ac784c27 100644
--- a/src/arch/riscv/trap_handler.c
+++ b/src/arch/riscv/trap_handler.c
@@ -14,10 +14,11 @@
* GNU General Public License for more details.
*/
-#include <console/console.h>
#include <arch/exception.h>
+#include <console/console.h>
#include <spike_util.h>
#include <string.h>
+#include <vm.h>
#define HART_ID 0
#define CONSOLE_PUT 1
@@ -171,14 +172,16 @@ void trap_handler(trapframe *tf) {
die("Can't recover from trap. Halting.\n");
}
+static uint32_t fetch_instruction(uintptr_t vaddr) {
+ printk(BIOS_SPEW, "fetching instruction at 0x%016zx\n", (size_t)vaddr);
+ return mprv_read_u32((uint32_t *) vaddr);
+}
+
void handle_misaligned_load(trapframe *tf) {
printk(BIOS_DEBUG, "Trapframe ptr: %p\n", tf);
printk(BIOS_DEBUG, "Stored sp: %p\n", (void*) tf->gpr[2]);
- insn_t faultingInstruction = 0;
uintptr_t faultingInstructionAddr = tf->epc;
- asm("move t0, %0" : /* No outputs */ : "r"(faultingInstructionAddr));
- asm("lw t0, 0(t0)");
- asm("move %0, t0" : "=r"(faultingInstruction));
+ insn_t faultingInstruction = fetch_instruction(faultingInstructionAddr);
printk(BIOS_DEBUG, "Faulting instruction: 0x%x\n", faultingInstruction);
insn_t widthMask = 0x7000;
insn_t memWidth = (faultingInstruction & widthMask) >> 12;
@@ -188,7 +191,12 @@ void handle_misaligned_load(trapframe *tf) {
if (memWidth == 3) {
// load double, handle the issue
void* badAddress = (void*) tf->badvaddr;
- memcpy(&(tf->gpr[destRegister]), badAddress, 8);
+ uint64_t value = 0;
+ for (int i = 0; i < 8; i++) {
+ value <<= 8;
+ value += mprv_read_u8(badAddress+i);
+ }
+ tf->gpr[destRegister] = value;
} else {
// panic, this should not have happened
printk(BIOS_DEBUG, "Code should not reach this path, misaligned on a non-64 bit store/load\n");
@@ -203,11 +211,8 @@ void handle_misaligned_load(trapframe *tf) {
void handle_misaligned_store(trapframe *tf) {
printk(BIOS_DEBUG, "Trapframe ptr: %p\n", tf);
printk(BIOS_DEBUG, "Stored sp: %p\n", (void*) tf->gpr[2]);
- insn_t faultingInstruction = 0;
uintptr_t faultingInstructionAddr = tf->epc;
- asm("move t0, %0" : /* No outputs */ : "r"(faultingInstructionAddr));
- asm("lw t0, 0(t0)");
- asm("move %0, t0" : "=r"(faultingInstruction));
+ insn_t faultingInstruction = fetch_instruction(faultingInstructionAddr);
printk(BIOS_DEBUG, "Faulting instruction: 0x%x\n", faultingInstruction);
insn_t widthMask = 0x7000;
insn_t memWidth = (faultingInstruction & widthMask) >> 12;
@@ -217,8 +222,11 @@ void handle_misaligned_store(trapframe *tf) {
if (memWidth == 3) {
// store double, handle the issue
void* badAddress = (void*) tf->badvaddr;
- long valueToStore = tf->gpr[srcRegister];
- memcpy(badAddress, &valueToStore, 8);
+ uint64_t value = tf->gpr[srcRegister];
+ for (int i = 0; i < 8; i++) {
+ mprv_write_u8(badAddress+i, value);
+ value >>= 8;
+ }
} else {
// panic, this should not have happened
printk(BIOS_DEBUG, "Code should not reach this path, misaligned on a non-64 bit store/load\n");