Implement CRC32 algorithm for RISC-V.

[fw/openocd] / src / target / riscv / riscv.c

diff --git a/src/target/riscv/riscv.c b/src/target/riscv/riscv.c
index c26e6358fde2245fcec8dfd578ff938bbb8d16d7..c883b420300675fb342f3190d8d0900f18c8afc2 100644 (file)
--- a/src/target/riscv/riscv.c
+++ b/src/target/riscv/riscv.c
@@ -1853,7 +1853,86 @@ static int riscv_checksum_memory(struct target *target,
                target_addr_t address, uint32_t count,
                uint32_t *checksum)
 {
-       return ERROR_FAIL;
+       struct working_area *crc_algorithm;
+       struct reg_param reg_params[2];
+       int retval;
+
+       LOG_DEBUG("address=0x%" TARGET_PRIxADDR "; count=0x%" PRIx32, address, count);
+
+       static const uint8_t riscv32_crc_code[] = {
+#include "../../contrib/loaders/checksum/riscv32_crc.inc"
+       };
+       static const uint8_t riscv64_crc_code[] = {
+#include "../../contrib/loaders/checksum/riscv64_crc.inc"
+       };
+
+       static const uint8_t *crc_code;
+
+       unsigned xlen = riscv_xlen(target);
+       unsigned crc_code_size;
+       if (xlen == 32) {
+               crc_code = riscv32_crc_code;
+               crc_code_size = sizeof(riscv32_crc_code);
+       } else {
+               crc_code = riscv64_crc_code;
+               crc_code_size = sizeof(riscv64_crc_code);
+       }
+
+       if (count < crc_code_size * 4) {
+               /* Don't use the algorithm for relatively small buffers. It's faster
+                * just to read the memory.  target_checksum_memory() will take care of
+                * that if we fail. */
+               return ERROR_FAIL;
+       }
+
+       retval = target_alloc_working_area(target, crc_code_size, &crc_algorithm);
+       if (retval != ERROR_OK)
+               return retval;
+
+       if (crc_algorithm->address + crc_algorithm->size > address &&
+                       crc_algorithm->address < address + count) {
+               /* Region to checksum overlaps with the work area we've been assigned.
+                * Bail. (Would be better to manually checksum what we read there, and
+                * use the algorithm for the rest.) */
+               target_free_working_area(target, crc_algorithm);
+               return ERROR_FAIL;
+       }
+
+       retval = target_write_buffer(target, crc_algorithm->address, crc_code_size,
+                       crc_code);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("Failed to write code to " TARGET_ADDR_FMT ": %d",
+                               crc_algorithm->address, retval);
+               target_free_working_area(target, crc_algorithm);
+               return retval;
+       }
+
+       init_reg_param(&reg_params[0], "a0", xlen, PARAM_IN_OUT);
+       init_reg_param(&reg_params[1], "a1", xlen, PARAM_OUT);
+       buf_set_u64(reg_params[0].value, 0, xlen, address);
+       buf_set_u64(reg_params[1].value, 0, xlen, count);
+
+       /* 20 second timeout/megabyte */
+       int timeout = 20000 * (1 + (count / (1024 * 1024)));
+
+       retval = target_run_algorithm(target, 0, NULL, 2, reg_params,
+                       crc_algorithm->address,
+                       0,      /* Leave exit point unspecified because we don't know. */
+                       timeout, NULL);
+
+       if (retval == ERROR_OK)
+               *checksum = buf_get_u32(reg_params[0].value, 0, 32);
+       else
+               LOG_ERROR("error executing RISC-V CRC algorithm");
+
+       destroy_reg_param(&reg_params[0]);
+       destroy_reg_param(&reg_params[1]);
+
+       target_free_working_area(target, crc_algorithm);
+
+       LOG_DEBUG("checksum=0x%" PRIx32 ", result=%d", *checksum, retval);
+
+       return retval;
 }
 
 /*** OpenOCD Helper Functions ***/