sp1: mm: Add physical memory management groundwork

Signed-off-by: Ian Moffett <ian@mirocom.org>

usr/src/sp1/common/Makefile

@@ -12,6 +12,7 @@
 CFILES = $(shell find os/ -name "*.c")
 CFILES += $(shell find io/ -name "*.c")
 CFILES += $(shell find bpt/ -name "*.c")
+CFILES += $(shell find mm/ -name "*.c")
 CFILES += $(shell find ../ext -name "*.c")
 CFILES += $(shell find ../lib -name "*.c")
 

usr/src/sp1/common/mm/vm_physseg.c

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#include <sys/param.h>
+#include <sys/units.h>
+#include <mm/physmem.h>
+#include <mu/param.h>
+#include <lib/printf.h>
+#include <os/bpt.h>
+
+#define pr_trace(fmt, ...) \
+    printf("physseg: " fmt, ##__VA_ARGS__)
+
+/* Use to convert type constants to strings */
+#define MEM_TYPE(TYPE)          \
+    ((TYPE) < NELEM(typetab))   \
+        ? typetab[(TYPE)]       \
+        : "invalid"
+
+/*
+ * Memory type constant to human readable
+ * string table.
+ */
+static const char *typetab[] = {
+    [MEMORY_USABLE]         = "usable",
+    [MEMORY_RESERVED]       = "reserved",
+    [MEMORY_ACPI_RECLAIM]   = "acpi reclaimable",
+    [MEMORY_ACPI_NVS]       = "acpi nvs",
+    [MEMORY_BAD]            = "bad*",
+    [MEMORY_BOOTLOADER]     = "bootloader",
+    [MEMORY_KERNEL]         = "syspaw",
+    [MEMORY_FRAMEBUFFER]    = "framebuffer",
+    [MEMORY_ACPI_TABLES]    = "acpi tables"
+};
+
+/* Memory stats */
+static uintptr_t highest_usable;
+static size_t mem_total = 0;
+static size_t mem_usable = 0;
+
+static inline void
+physmem_print_size(const char *title, size_t len)
+{
+    if (title == NULL) {
+        return;
+    }
+
+    if (len >= UNIT_GIB) {
+        pr_trace("... %d GiB %s\n", len / UNIT_GIB, title);
+    } else if (len >= UNIT_MIB) {
+        pr_trace("... %d MiB %s\n", len / UNIT_MIB, title);
+    } else {
+        pr_trace("... %d bytes %s\n", len, title);
+    }
+}
+
+/*
+ * Begin scanning physical memory for usable entries
+ * and other information
+ */
+static void
+physmem_probe(void)
+{
+    struct mem_entry entry;
+    status_t status;
+
+    for (size_t i = 0;; ++i) {
+        status = bpt_mem_entry_i(i, &entry);
+
+        /* Are there no more entries? */
+        if (status != STATUS_SUCCESS) {
+            break;
+        }
+
+        /* Print this entry */
+        pr_trace(
+            "%p ... %p : %s\n",
+            entry.base,
+            entry.base + entry.length,
+            MEM_TYPE(entry.type)
+        );
+
+        mem_total += entry.length;
+
+        /* Skip non-usable memory from here on out */
+        if (entry.type != MEMORY_USABLE) {
+            continue;
+        }
+
+        if ((entry.base + entry.length) > highest_usable) {
+            highest_usable = ALIGN_UP(entry.base + entry.length, PAGESIZE);
+        }
+
+        mem_usable += entry.length;
+    }
+
+    /* Print memory stats */
+    pr_trace("begin stats\n");
+    physmem_print_size("usable", mem_usable);
+    physmem_print_size("total", mem_total);
+}
+
+void
+mm_physmem_init(void)
+{
+    /* Probe the physical memory */
+    pr_trace("sniffing out physical memory...\n");
+    physmem_probe();
+}

usr/src/sp1/common/os/main.c

@@ -13,6 +13,7 @@
 #include <os/bpt.h>
 #include <lib/printf.h>
 #include <mu/cpu.h>
+#include <mm/physmem.h>
 
 #define KERNEL_VERSION "0.0.1"
 
@@ -46,4 +47,7 @@ main(void)
 
     /* Initialize boot protocol translation layer */
     bpt_init();
+
+    /* Initialize physical memory management */
+    mm_physmem_init();
 }

usr/src/sp1/head/mm/physmem.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#ifndef _MM_PHYSMEM_H_
+#define _MM_PHYSMEM_H_ 1
+
+/*
+ * Initialize the physical memory management
+ */
+void mm_physmem_init(void);
+
+#endif  /* !_MM_PHYSMEM_H_ */