sp1: bpt: Add boot protocol translation layer

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

usr/src/mk/sys.mk

@@ -11,6 +11,7 @@
 
 CC_PREFIX = x86_64-pc-mirocom
 ARCH_TARGET = amd64
+BOOT_PROTO = limine
 
 CC = \
 	var/cc/toolchain/gcc/bin/$(CC_PREFIX)-gcc
@@ -28,7 +29,7 @@ SYS_CFLAGS =			\
 	-mcmodel=kernel		\
 	-Wno-attributes		\
 	-fno-stack-protector\
-	-D_SP1_MULTICORE
+	-D_SP1_MULTICORE    \
 
 ifeq ($(ARCH_TARGET),x86_64)
 	SYS_CFLAGS += 		\
@@ -46,4 +47,5 @@ PASSDOWN_ARGS = \
 	ARCH=$(ARCH_TARGET)		\
 	SYS_CC=$(CC)			\
 	SYS_LD=$(LD)			\
-	SYS_CFLAGS="$(SYS_CFLAGS)"
+	SYS_CFLAGS="$(SYS_CFLAGS)" \
+	BOOT_PROTO="\"$(BOOT_PROTO)\""

usr/src/sp1/common/Makefile

@@ -11,6 +11,7 @@
 
 CFILES = $(shell find os/ -name "*.c")
 CFILES += $(shell find io/ -name "*.c")
+CFILES += $(shell find bpt/ -name "*.c")
 CFILES += $(shell find ../ext -name "*.c")
 CFILES += $(shell find ../lib -name "*.c")
 
@@ -28,7 +29,8 @@ CFLAGS = 			\
 	-D_KERNEL		\
 	-MMD			\
 	-DPRINTF_DISABLE_SUPPORT_PTRDIFF_T \
-	-DPRINTF_DISABLE_SUPPORT_FLOAT
+	-DPRINTF_DISABLE_SUPPORT_FLOAT     \
+	-D_BOOT_PROTO="\"$(BOOT_PROTO)\""
 
 .PHONY: all
 all: $(OFILES)

usr/src/sp1/common/bpt/bpt.c

@@ -0,0 +1,53 @@
+/*
+ * 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 <os/bpt.h>
+#include <lib/limine.h>
+#include <string.h>
+
+#ifndef _BOOT_PROTO
+#error "Boot protocol not defined!"
+#else
+#define BOOT_PROTO _BOOT_PROTO
+#endif  /* !_BOOT_PROTO */
+
+/* Boot protocol translation operations */
+static struct bpt_ops ops;
+
+status_t
+bpt_get_protovar(struct bpt_protovar *res)
+{
+    if (res == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    if (ops.get_protovar == NULL) {
+        return STATUS_IO_ERROR;
+    }
+
+    return ops.get_protovar(res);
+}
+
+status_t
+bpt_init(void)
+{
+    switch (*BOOT_PROTO) {
+    case 'l':
+        if (memcmp(BOOT_PROTO, "limine", 6) == 0) {
+            bpt_init_limine(&ops);
+            return STATUS_SUCCESS;
+        }
+
+        break;
+    }
+
+    return STATUS_INVALID_PARAM;
+}

usr/src/sp1/common/bpt/bpt_limine.c

@@ -0,0 +1,49 @@
+/*
+ * 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 <os/bpt.h>
+#include <lib/limine.h>
+#include <lib/printf.h>
+
+/* HHDM request */
+static struct limine_hhdm_response *hhdm_resp = NULL;
+static volatile struct limine_hhdm_request hhdm_req = {
+    .id = LIMINE_HHDM_REQUEST,
+    .revision = 0
+};
+
+/*
+ * Obtain the boot protocol variables
+ *
+ * @res: Result is written here
+ */
+static status_t
+limine_get_protovar(struct bpt_protovar *res)
+{
+    if (res == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    res->kload_base = hhdm_resp->offset;
+    return STATUS_SUCCESS;
+}
+
+status_t
+bpt_init_limine(struct bpt_ops *ops)
+{
+    if (ops == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    hhdm_resp = hhdm_req.response;
+    ops->get_protovar = limine_get_protovar;
+    return STATUS_SUCCESS;
+}

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

@@ -10,6 +10,7 @@
  */
 
 #include <io/cons/cons.h>
+#include <os/bpt.h>
 #include <lib/printf.h>
 #include <mu/cpu.h>
 
@@ -42,4 +43,7 @@ main(void)
 
     /* Pre-init the processor */
     mu_cpu_preinit(&bsp);
+
+    /* Initialize boot protocol translation layer */
+    bpt_init();
 }

usr/src/sp1/head/os/bpt.h

@@ -0,0 +1,50 @@
+/*
+ * 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 _OS_BPT_H_
+#define _OS_BPT_H_ 1
+
+#include <sys/types.h>
+#include <sys/status.h>
+
+/*
+ * The protovar stores a list of information passed
+ * by the bootloader.
+ *
+ * @kload_base:  Kernel load base
+ */
+struct bpt_protovar {
+    uintptr_t kload_base;
+};
+
+/*
+ * Operations associated with a specific boot protocol
+ */
+struct bpt_ops {
+    status_t(*get_protovar)(struct bpt_protovar *res);
+};
+
+/*
+ * Obtain the protocol variable structure reference
+ *
+ * @res: Result is written here
+ */
+status_t bpt_get_protovar(struct bpt_protovar *res);
+
+/*
+ * Initialize the boot protocol translation layer
+ */
+status_t bpt_init(void);
+
+/* Boot protocol specific init funcs */
+status_t bpt_init_limine(struct bpt_ops *ops);
+
+#endif  /* !_OS_BPT_H_ */