fix up printf functions at last, and remove sprintf

Author: braindigitalis

include/acpi.h

@@ -130,20 +130,6 @@ typedef struct pci_irq_route {
  */
 void init_acpi();
 
-/**
- * @brief Get total number of CPUs detected via ACPI.
- *
- * @return Number of CPUs detected.
- */
-uint16_t get_cpu_count();
-
-/**
- * @brief Retrieve the physical address of the Local APIC MMIO.
- *
- * @return 64-bit physical address of LAPIC base.
- */
-uint64_t get_local_apic();
-
 /**
  * @brief Retrieve the IOAPIC structure by index.
  *

include/devicename.h

@@ -12,7 +12,7 @@ typedef struct devname_prefix_t {
 	uint8_t increment;
 } devname_prefix_t;
 
-bool make_unique_device_name(const char* prefix, char* buffer);
+bool make_unique_device_name(const char* prefix, char* buffer, size_t buffer_len);
 
 void init_devicenames();
 

include/printf.h

@@ -1,50 +1,138 @@
 /**
- * @file printf.h
- * @author Craig Edwards (craigedwards@brainbox.cc)
- * @copyright Copyright (c) 2012-2025
+ * @file printf.c
+ * @author Craig Edwards
+ * @copyright 2012–2025
+ *
+ * @brief Minimal printf implementation for Retro Rocket
+ *
+ * @section provenance Provenance
+ * This implementation originated from a public-domain printf clone
+ * commonly circulated in early OSDev / hobbyist C runtimes. The original
+ * code dates back to the 1990s, likely adapted from 16‑bit DOS/Minix
+ * environments where:
+ *   - `PR_16` meant "use 16‑bit short",
+ *   - `PR_32` meant "use 32‑bit long",
+ *   - `PR_FP` supported "far pointers",
+ * and short identifiers were required because some compilers only
+ * guaranteed 8‑character identifier uniqueness.
+ *
+ * This version has since been heavily modernised:
+ *   - All 16‑bit and far pointer cruft removed.
+ *   - Flags renamed for clarity (`PR_INT32`, `PR_INT64`, `PR_WAS_NEG`).
+ *   - Goto-based control flow replaced with structured `switch`/`if`.
+ *   - Doxygen-style documentation added.
+ *   - Confirmed fit for 32‑/64‑bit protected mode systems.
+ *
+ * While the skeleton came from public domain code, the current
+ * implementation is effectively a clean-room rework and is considered
+ * part of the Retro Rocket codebase.
+ *
+ * @section limitations Limitations
+ * - Floating point formats (%f, %e, %g) are not implemented.
+ * - Width/precision parsing is minimal.
+ * - Thread safety relies on external spinlocks around vprintf/dprintf.
+ *
+ * @section intent Intent
+ * The purpose of this implementation is to provide a lightweight,
+ * dependency-free printf family for kernel and low-level userland code,
+ * suitable for use in kernel code where full libc is not available.
  */
+
 #pragma once
 
 #include "kernel.h"
 
+/**
+ * @brief Variadic argument support
+ * GCC/Clang builtins are used for variadic argument handling,
+ * ensuring this remains freestanding without requiring stdarg.h.
+ */
 typedef __builtin_va_list va_list;
 #define va_start(ap, X) __builtin_va_start(ap, X)
 #define va_arg(ap, type) __builtin_va_arg(ap, type)
 #define va_end(ap) __builtin_va_end(ap)
 
-/* flags used in processing format string */
-#define PR_LJ   0x001    /* left justify */
-#define PR_CA   0x002    /* use A-F instead of a-f for hex */
-#define PR_SG   0x004    /* signed numeric conversion (%d vs. %u) */
-#define PR_32   0x008    /* long (32-bit) numeric conversion */
-#define PR_16   0x010    /* short (16-bit) numeric conversion */
-#define PR_WS   0x020    /* PR_SG set and num was < 0 */
-#define PR_LZ   0x040    /* pad left with '0' instead of ' ' */
-#define PR_FP   0x080    /* pointers are far */
-#define PR_64   0x100    /* long (32-bit) numeric conversion */
-/* largest number handled is 2^64-1, lowest radix handled is 8.
-2^64-1 in base 8 has 21 digits (add 5 for trailing NUL and for slop) */
-#define PR_BUFLEN       26
+/**
+ * @brief Format Flags
+ *
+ * These flags are set during format string parsing and affect the
+ * behaviour of string/number emission. They may be combined.
+ */
+#define PR_LEFT_JUSTIFY	0x001    /**< Left justify within field width (%-d). */
+#define PR_UPPER_HEX	0x002    /**< Use A–F instead of a–f for hex digits (%X). */
+#define PR_SIGNED	0x004    /**< Signed numeric conversion (%d vs. %u). */
+#define PR_INT64   	0x008    /**< Treat numeric as 32-bit long. */
+#define PR_INT32	0x010    /**< Treat numeric as 16-bit short. */
+#define PR_WAS_NEG	0x020    /**< Write sign ('-') because PR_SG was set and number < 0. */
+#define PR_LEFT_ZEROES	0x040    /**< Pad left with zeroes instead of spaces. */
 
-typedef int (*fnptr_t)(unsigned c, void **helper, const void* end);
+/**
+ * @brief Maximum temporary buffer length for number-to-string conversion.
+ *
+ * Largest number handled is 2^64–1. In base 8, this is 21 digits.
+ * Add 1 for sign, 1 for NUL terminator, and a few for slop.
+ */
+#define PR_BUFLEN 26
 
-int vsprintf(char *buf, const char *fmt, va_list args);
+/**
+ * @brief Output Function Type
+ *
+ * Each printf variant passes characters to a callback function
+ * of this type. This decouples formatting from the output device.
+ *
+ * @param c       Character to output
+ * @param helper  Opaque pointer (e.g. buffer write position)
+ * @param end     End-of-buffer guard (if bounded)
+ * @return        0 on success, nonzero if buffer/device is full
+ */
+typedef int (*fnptr_t)(unsigned c, void **helper, const void* end);
 
+/**
+ * @brief Write formatted output to a string buffer with max size.
+ * @param buf Output buffer
+ * @param max Maximum number of characters (including NUL terminator)
+ * @param fmt Format string
+ * @param args Variadic argument list
+ * @return Number of characters written (excluding NUL terminator)
+ */
 int vsnprintf(char *buf, size_t max, const char *fmt, va_list args);
 
-int sprintf(char *buf, const char *fmt, ...);
-
+/**
+ * @brief Write formatted output to a string buffer with max size.
+ * @param buf Output buffer
+ * @param max Maximum number of characters (including NUL terminator)
+ * @param fmt Format string
+ * @param ... Format arguments
+ * @return Number of characters written (excluding NUL terminator)
+ */
 int snprintf(char *buf, size_t max, const char *fmt, ...);
 
+/**
+ * @brief Write formatted output to the active console.
+ *        Thread-safe via spinlocks.
+ * @param fmt Format string
+ * @param args Variadic argument list
+ * @return Number of characters written
+ */
 int vprintf(const char *fmt, va_list args);
 
+/**
+ * @brief Write formatted output to the active console.
+ *        Thread-safe via spinlocks.
+ * @param fmt Format string
+ * @param ... Format arguments
+ * @return Number of characters written
+ */
 int printf(const char *fmt, ...);
 
 /**
- * @brief Debug only to int 0xE9
- * 
- * @param fmt format specifier
- * @param ... format args
- * @return int number of printed characters
+ * @brief Debug output only (I/O port 0xE9).
+ *
+ * Characters are written to the Bochs/QEMU debug console,
+ * prefixed with a timestamp (kernel tick count).
+ *
+ * @param fmt Format string
+ * @param ... Format arguments
+ * @return Number of characters written
  */
 int dprintf(const char *fmt, ...);

src/ahci.c

@@ -205,7 +205,7 @@ void probe_port(ahci_hba_mem_t *abar, pci_dev_t dev)
 				sd->blockread = storage_device_ahci_block_read;
 				sd->blockwrite = storage_device_ahci_block_write;
 				sd->size = dt == AHCI_DEV_SATA ? ahci_read_size(&abar->ports[i], abar) : SIZE_MAX;
-				make_unique_device_name(dt == AHCI_DEV_SATA ? "hd" : "cd", sd->name);
+				make_unique_device_name(dt == AHCI_DEV_SATA ? "hd" : "cd", sd->name, sizeof(sd->name));
 				sd->block_size = dt == AHCI_DEV_SATA ? HDD_SECTOR_SIZE : ATAPI_SECTOR_SIZE;
 				register_storage_device(sd);
 			}

src/basic/main.c

@@ -532,7 +532,7 @@ bool accept(int token, struct basic_ctx* ctx)
 	if (token != tokenizer_token(ctx)) {
 		char err[MAX_STRINGLEN];
 		GENERATE_ENUM_STRING_NAMES(TOKEN, token_names)
-		sprintf(err, "Expected %s got %s", token_names[token], token_names[tokenizer_token(ctx)]);
+		snprintf(err, MAX_STRINGLEN, "Expected %s got %s", token_names[token], token_names[tokenizer_token(ctx)]);
 		tokenizer_error_print(ctx, err);
 		return false;
 	}

src/basic/string.c

@@ -294,7 +294,7 @@ char* basic_itoa(struct basic_ctx* ctx)
 	PARAMS_GET_ITEM(BIP_INT);
 	int64_t radix = intval;
 	PARAMS_END("RADIX$", "");
-	char buffer[128] = {0};
+	char buffer[MAX_STRINGLEN] = {0};
 	int err;
 	if ((err = do_itoa(target, buffer, radix)) >= 0) {
 		return gc_strdup(buffer);
@@ -304,7 +304,7 @@ char* basic_itoa(struct basic_ctx* ctx)
 		tokenizer_error_print(ctx, "Invalid radix (not in range between 2 and 36)");
 		return "";
 	}
-	sprintf(buffer, "Unknown `do_itoa` error: %d", -err);
+	snprintf(buffer, MAX_STRINGLEN, "Unknown `do_itoa` error: %d", -err);
 	tokenizer_error_print(ctx, buffer);
 	return "";
 }

src/basic/variable.c

@@ -418,8 +418,8 @@ const char* basic_get_string_variable(const char* var, struct basic_ctx* ctx)
 		}
 	}
 
-	char err[1024];
-	sprintf(err, "No such string variable '%s'", var);
+	char err[MAX_STRINGLEN];
+	snprintf(err, MAX_STRINGLEN, "No such string variable '%s'", var);
 	tokenizer_error_print(ctx, err);
 	return "";
 }
@@ -566,9 +566,9 @@ bool basic_get_double_variable(const char* var, struct basic_ctx* ctx, double* r
 	}
 
 
-	char err[1024];
+	char err[MAX_STRINGLEN];
 	if (var[strlen(var) - 1] == '#') {
-		sprintf(err, "No such real variable '%s'", var);
+		snprintf(err, MAX_STRINGLEN, "No such real variable '%s'", var);
 		tokenizer_error_print(ctx, err);
 	}
 	*res = 0.0; /* No such variable */

src/devicename.c

@@ -14,7 +14,7 @@ uint64_t string_hash(const void *item, uint64_t seed0, uint64_t seed1) {
 	return hashmap_sip(a->prefix, strlen(a->prefix), seed0, seed1);
 }
 
-bool make_unique_device_name(const char* prefix, char* buffer)
+bool make_unique_device_name(const char* prefix, char* buffer, size_t buffer_len)
 {
 	if (prefix == NULL || buffer == NULL) {
 		return false;
@@ -31,7 +31,7 @@ bool make_unique_device_name(const char* prefix, char* buffer)
 		hashmap_set(prefix_hash, &find);
 		exists = &find;
 	}
-	sprintf(buffer, "%s%d", prefix, prefix_increment);
+	snprintf(buffer, buffer_len, "%s%d", prefix, prefix_increment);
 	dprintf("Registered new device name: %s\n", buffer);
 	add_random_entropy((uint64_t)buffer); // NOTE: *address* used as entropy!
 	hashmap_set(prefix_hash, exists);

src/e1000.c

@@ -376,7 +376,7 @@ bool e1000_start(pci_dev_t *pci_device) {
 	}
 	net->opaque = NULL;
 	net->deviceid = (INTEL_VEND << 16) | e1000_device_id;
-	make_unique_device_name("net", net->name);
+	make_unique_device_name("net", net->name, sizeof(net->name));
 	net->description = "Intel e1000 Gigabit";
 	net->flags = CONNECTED;
 	net->mtu = 0;

src/keyboard.c

@@ -175,7 +175,7 @@ void init_keyboard()
 	char devname[16];
 	buffer_write_ptr = 0;
 	buffer_read_ptr = 0;
-	make_unique_device_name("kb", devname);
+	make_unique_device_name("kb", devname, sizeof(devname));
 	register_interrupt_handler(IRQ1, keyboard_handler, dev_zero, NULL);
 	proc_register_idle(keyboard_repeat_tick, IDLE_BACKGROUND);
 }