sw: add idma library functions

Author: phsauter

sw/config.h

@@ -12,6 +12,7 @@
 #define UART_BASE_ADDR 0x03002000
 #define GPIO_BASE_ADDR 0x03005000
 #define OBI_TIMER_BASE_ADDR 0x0300A000
+#define IDMA_BASE_ADDR 0x0300B000
 #define CLINT_BASE_ADDR 0x02040000
 
 // Frequencies
@@ -31,3 +32,4 @@
 #define IRQ_OBI_TIMER 16
 #define IRQ_UART 17
 #define IRQ_GPIO 18
+#define IRQ_IDMA 19

sw/lib/inc/idma.h

@@ -0,0 +1,53 @@
+// Copyright 2026 ETH Zurich and University of Bologna.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Thomas Benz <tbenz@iis.ee.ethz.ch>
+// Philippe Sauter <phsauter@iis.ee.ethz.ch>
+
+#pragma once
+
+#include <stdint.h>
+
+// Register offsets (from croc_idma.sv)
+#define IDMA_CONF_OFFSET         0x00
+#define IDMA_NEXT_ID_OFFSET      0x44
+#define IDMA_DONE_ID_OFFSET      0x84
+#define IDMA_DST_ADDR_OFFSET     0xd0
+#define IDMA_SRC_ADDR_OFFSET     0xd8
+#define IDMA_LENGTH_OFFSET       0xe0
+#define IDMA_DST_STRIDE_2_OFFSET 0xe8
+#define IDMA_SRC_STRIDE_2_OFFSET 0xf0
+#define IDMA_REPS_2_OFFSET       0xf8
+
+// Config register bits
+#define IDMA_CONF_ND_ENA_BIT 11
+
+// Configure a simple 1D DMA transfer
+void idma_set_src_addr(uint32_t addr);
+void idma_set_dst_addr(uint32_t addr);
+void idma_set_length(uint32_t length);
+
+// Configure 2D (ND) transfers
+void idma_set_nd_enable(int enable);
+void idma_set_src_stride(uint32_t stride);
+void idma_set_dst_stride(uint32_t stride);
+void idma_set_reps(uint32_t reps);
+
+// Launch a transfer and return the job ID.
+// Reading NEXT_ID submits the job configured in the registers.
+uint32_t idma_launch(void);
+
+// Return the ID of the last completed transfer
+uint32_t idma_done_id(void);
+
+// Check if a transfer with the given job ID has completed
+uint32_t idma_is_done(uint32_t job_id);
+
+// Launch a blocking 1D memory copy and return the job ID
+uint32_t idma_memcpy(uint32_t dst, uint32_t src, uint32_t length);
+
+// Launch a blocking 2D transfer and return the job ID
+uint32_t idma_memcpy_2d(uint32_t dst, uint32_t src, uint32_t length,
+                        uint32_t dst_stride, uint32_t src_stride,
+                        uint32_t reps);

sw/lib/src/idma.c

@@ -0,0 +1,88 @@
+// Copyright 2026 ETH Zurich and University of Bologna.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Thomas Benz <tbenz@iis.ee.ethz.ch>
+// Philippe Sauter <phsauter@iis.ee.ethz.ch>
+
+#include "idma.h"
+#include "util.h"
+#include "config.h"
+
+////////////////////////
+//  Register access   //
+////////////////////////
+
+void idma_set_src_addr(uint32_t addr) {
+    *reg32(IDMA_BASE_ADDR, IDMA_SRC_ADDR_OFFSET) = addr;
+}
+
+void idma_set_dst_addr(uint32_t addr) {
+    *reg32(IDMA_BASE_ADDR, IDMA_DST_ADDR_OFFSET) = addr;
+}
+
+void idma_set_length(uint32_t length) {
+    *reg32(IDMA_BASE_ADDR, IDMA_LENGTH_OFFSET) = length;
+}
+
+void idma_set_nd_enable(int enable) {
+    uint32_t conf = *reg32(IDMA_BASE_ADDR, IDMA_CONF_OFFSET);
+    if (enable)
+        conf |= (1u << IDMA_CONF_ND_ENA_BIT);
+    else
+        conf &= ~(1u << IDMA_CONF_ND_ENA_BIT);
+    *reg32(IDMA_BASE_ADDR, IDMA_CONF_OFFSET) = conf;
+}
+
+void idma_set_src_stride(uint32_t stride) {
+    *reg32(IDMA_BASE_ADDR, IDMA_SRC_STRIDE_2_OFFSET) = stride;
+}
+
+void idma_set_dst_stride(uint32_t stride) {
+    *reg32(IDMA_BASE_ADDR, IDMA_DST_STRIDE_2_OFFSET) = stride;
+}
+
+void idma_set_reps(uint32_t reps) {
+    *reg32(IDMA_BASE_ADDR, IDMA_REPS_2_OFFSET) = reps;
+}
+
+uint32_t idma_launch(void) {
+    return *reg32(IDMA_BASE_ADDR, IDMA_NEXT_ID_OFFSET);
+}
+
+uint32_t idma_done_id(void) {
+    return *reg32(IDMA_BASE_ADDR, IDMA_DONE_ID_OFFSET);
+}
+
+uint32_t idma_is_done(uint32_t job_id) {
+    return idma_done_id() >= job_id;
+}
+
+////////////////////////
+//  Convenience API   //
+////////////////////////
+
+uint32_t idma_memcpy(uint32_t dst, uint32_t src, uint32_t length) {
+    idma_set_nd_enable(0);
+    idma_set_src_addr(src);
+    idma_set_dst_addr(dst);
+    idma_set_length(length);
+    uint32_t id = idma_launch();
+    while (!idma_is_done(id));
+    return id;
+}
+
+uint32_t idma_memcpy_2d(uint32_t dst, uint32_t src, uint32_t length,
+                        uint32_t dst_stride, uint32_t src_stride,
+                        uint32_t reps) {
+    idma_set_nd_enable(1);
+    idma_set_src_addr(src);
+    idma_set_dst_addr(dst);
+    idma_set_length(length);
+    idma_set_dst_stride(dst_stride);
+    idma_set_src_stride(src_stride);
+    idma_set_reps(reps);
+    uint32_t id = idma_launch();
+    while (!idma_is_done(id));
+    return id;
+}