104 lines
3.4 KiB
C
104 lines
3.4 KiB
C
/*
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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This file is part of the StarForth project.
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Licensed under the StarForth License, Version 1.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at:
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https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
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This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
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express or implied, including but not limited to the warranties of
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merchantability, fitness for a particular purpose, and noninfringement.
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See the License for the specific language governing permissions and
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limitations under the License.
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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This file is part of the StarForth project.
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Licensed under the StarForth License, Version 1.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at:
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https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
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This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
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express or implied, including but not limited to the warranties of
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merchantability, fitness for a particular purpose, and noninfringement.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#include "io.h"
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#include "log.h"
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#include <string.h>
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/** @} */
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/**
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* @brief Initialize the IO subsystem
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* @param vm Pointer to VM instance
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*
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* Initializes the block device view over the unified VM memory.
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* Zeros out the entire VM memory space.
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*/
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void io_init(VM *vm) {
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if (!vm || !vm->memory) {
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log_message(LOG_ERROR, "io_init: VM or VM memory not initialized");
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return;
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}
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/* Zero the entire VM address space so blocks start clean. */
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memset(vm->memory, 0, VM_MEMORY_SIZE);
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log_message(LOG_INFO,
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"IO subsystem initialized with %d blocks of %d bytes",
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(int) MAX_BLOCKS, (int) BLOCK_SIZE);
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}
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/*
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* @brief Write a block to VM memory
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* @param vm Pointer to VM instance
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* @param block_num Block number to write (0 to MAX_BLOCKS-1)
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* @param buffer Source buffer containing block data
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* @return 0 on success, -1 on error
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*/
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/**
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* @brief Write a block to VM memory
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* @param vm Pointer to VM instance
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* @param block_num Block number to write (0 to MAX_BLOCKS-1)
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* @param buffer Source buffer containing block data
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* @return 0 on success, -1 on error
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*
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* Writes a BLOCK_SIZE chunk of data from the provided buffer into the VM's memory
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* at the specified block number offset. The block number must be within valid range.
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* The entire block is written atomically.
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*
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* @note The buffer must contain at least BLOCK_SIZE bytes of valid data
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*/
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int io_write_block(VM *vm, int block_num, const unsigned char *buffer) {
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if (!vm || !vm->memory || !buffer) {
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log_message(LOG_ERROR, "io_write_block: bad args");
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return -1;
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}
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if (block_num < 0 || block_num >= (int) MAX_BLOCKS) {
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log_message(LOG_ERROR, "io_write_block: invalid block number %d", block_num);
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return -1;
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}
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size_t off = (size_t) block_num * (size_t) BLOCK_SIZE;
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memcpy(&vm->memory[off], buffer, BLOCK_SIZE);
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log_message(LOG_DEBUG, "io_write_block: wrote block %d", block_num);
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return 0;
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} |