[platform][qemu-m68k] expand the bootinfo parsing code

Break into a separate .c file.

platform/qemu-virt-m68k/bootinfo.c

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2024 Travis Geiselbrecht
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT
+ */
+#include "bootinfo.h"
+
+#include <lk/compiler.h>
+#include <lk/trace.h>
+#include <lk/debug.h>
+#include <stdio.h>
+
+#define LOCAL_TRACE 0
+
+extern uint8_t __bss_end;
+
+static const char *bootinfo_tag_to_string(enum BOOTINFO_TAGS tag) {
+    switch (tag) {
+        case BOOTINFO_TAG_END: return "END";
+        case BOOTINFO_TAG_MACHTYPE: return "MACHTYPE";
+        case BOOTINFO_TAG_CPUTYPE: return "CPUTYPE";
+        case BOOTINFO_TAG_FPUTYPE: return "FPUTYPE";
+        case BOOTINFO_TAG_MMUTYPE: return "MMUTYPE";
+        case BOOTINFO_TAG_MEMCHUNK: return "MEMCHUNK";
+        case BOOTINFO_TAG_RAMDISK: return "RAMDISK";
+        case BOOTINFO_TAG_COMMAND_LINE: return "COMMAND_LINE";
+        case BOOTINFO_TAG_RNG_SEED: return "RNG_SEED";
+        case BOOTINFO_TAG_VIRT_QEMU_VERSION: return "VIRT_QEMU_VERSION";
+        case BOOTINFO_TAG_VIRT_GF_PIC_BASE: return "VIRT_GF_PIC_BASE";
+        case BOOTINFO_TAG_VIRT_GF_RTC_BASE: return "VIRT_GF_RTC_BASE";
+        case BOOTINFO_TAG_VIRT_GF_TTY_BASE: return "VIRT_GF_TTY_BASE";
+        case BOOTINFO_TAG_VIRT_VIRTIO_BASE: return "VIRT_VIRTIO_BASE";
+        case BOOTINFO_TAG_VIRT_CTRL_BASE: return "VIRT_CTRL_BASE";
+        default: return "UNKNOWN";
+    }
+}
+
+static void dump_bootinfo_record(const struct bootinfo_item *item) {
+    printf("item %p: tag %hx (%s), size %hu\n", item, item->tag, bootinfo_tag_to_string(item->tag), item->size);
+    if (item->size > 4) {
+        hexdump8(item->data, item->size - 4);
+    }
+}
+
+void dump_all_bootinfo_records(void) {
+    const uint8_t *ptr = &__bss_end;
+
+    printf("bootinfo records at %p:\n", ptr);
+    for (;;) {
+        const struct bootinfo_item *item = (const struct bootinfo_item *)ptr;
+        if (item->tag == BOOTINFO_TAG_END) {
+            break;
+        }
+
+        dump_bootinfo_record(item);
+
+        // move to the next field
+        ptr += item->size;
+    }
+}
+
+// look for tags that qemu left at the end of the kernel that hold various
+// pieces of system configuration info.
+const void *bootinfo_find_record(uint16_t id, uint16_t *size_out) {
+    const uint8_t *ptr = &__bss_end;
+
+    *size_out = 0;
+    for (;;) {
+        const struct bootinfo_item *item = (const struct bootinfo_item *)ptr;
+        if (item->tag == BOOTINFO_TAG_END) {
+            return NULL;
+        }
+
+        if (LOCAL_TRACE > 2) {
+            dump_bootinfo_record(item);
+        }
+
+        if (item->tag == id) {
+            *size_out = item->size - 4;
+            return item->data;
+        } else if (item->tag == 0) { // end token
+            return NULL;
+        }
+
+        // move to the next field
+        ptr += item->size;
+    }
+}
+

platform/qemu-virt-m68k/bootinfo.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2024 Travis Geiselbrecht
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT
+ */
+#pragma once
+
+#include <stdint.h>
+
+// parse bootinfo
+struct bootinfo_item {
+    uint16_t tag;
+    uint16_t size;
+    uint32_t data[0];
+};
+
+// bootinfo tags (from QEMU)
+enum BOOTINFO_TAGS {
+    BOOTINFO_TAG_END = 0,
+    BOOTINFO_TAG_MACHTYPE = 1,
+    BOOTINFO_TAG_CPUTYPE = 2,
+    BOOTINFO_TAG_FPUTYPE = 3,
+    BOOTINFO_TAG_MMUTYPE = 4,
+    BOOTINFO_TAG_MEMCHUNK = 5,
+    BOOTINFO_TAG_RAMDISK = 6,
+    BOOTINFO_TAG_COMMAND_LINE = 7,
+    BOOTINFO_TAG_RNG_SEED = 8,
+    BOOTINFO_TAG_VIRT_QEMU_VERSION = 0x8000,
+    BOOTINFO_TAG_VIRT_GF_PIC_BASE = 0x8001,
+    BOOTINFO_TAG_VIRT_GF_RTC_BASE = 0x8002,
+    BOOTINFO_TAG_VIRT_GF_TTY_BASE = 0x8003,
+    BOOTINFO_TAG_VIRT_VIRTIO_BASE = 0x8004,
+    BOOTINFO_TAG_VIRT_CTRL_BASE = 0x8005,
+};
+
+void dump_all_bootinfo_records(void);
+const void *bootinfo_find_record(uint16_t id, uint16_t *size_out);
+
+// for BOOTINFO_TAG_*TYPE tags
+struct bootinfo_item_type {
+    uint32_t type;
+};
+
+// for BOOTINFO_TAG_VIRT_QEMU_VERSION
+struct bootinfo_item_qemu_version {
+    uint8_t major;
+    uint8_t minor;
+    uint8_t micro;
+    uint8_t unused__;
+};
+
+// for BOOTINFO_TAG_MEMCHUNK
+struct bootinfo_item_memchunk {
+    uint32_t base;
+    uint32_t size;
+};
+
+// for VIRT_*_BASE tags
+struct bootinfo_item_device {
+    uint32_t base;
+    uint32_t irq_base;
+};

platform/qemu-virt-m68k/platform.c

@@ -25,60 +25,39 @@
 #include <kernel/novm.h>
 #endif
 
+#include "bootinfo.h"
 #include "platform_p.h"
 
 #define LOCAL_TRACE 0
 
-extern uint8_t __bss_end;
-
-// parse bootinfo
-struct bootinfo_item {
-    uint16_t tag;
-    uint16_t size;
-    uint32_t data[0];
-};
-
-// look for tags that qemu left at the end of the kernel that hold various
-// pieces of system configuration info.
-static void *bootinfo_find_record(uint16_t id, uint16_t *size_out) {
-    uint8_t *ptr = &__bss_end;
-
-    *size_out = 0;
-    for (;;) {
-        struct bootinfo_item *item = (struct bootinfo_item *)ptr;
-
-        LTRACEF_LEVEL(2, "item %p: tag %hx, size %hu\n", item, item->tag, item->size);
-
-        if (item->tag == id) {
-            *size_out = item->size - 4;
-            return item->data;
-        } else if (item->tag == 0) { // end token
-            return NULL;
-        }
-
-        // move to the next field
-        ptr += item->size;
-    }
-}
-
 void platform_early_init(void) {
     goldfish_tty_early_init();
     pic_early_init();
     goldfish_rtc_early_init();
 
+    // Dump the bootinfo structure
+    if (LK_DEBUGLEVEL >= INFO) {
+        dump_all_bootinfo_records();
+    }
+
     // look for tag 0x5, which describes the memory layout of the system
     uint16_t size;
-    void *ptr = bootinfo_find_record(0x5, &size);
+    const void *ptr = bootinfo_find_record(BOOTINFO_TAG_MEMCHUNK, &size);
     if (!ptr) {
         panic("68K VIRT: unable to find MEMCHUNK BOOTINFO record\n");
     }
+    if (size < 8) {
+        panic("68K VIRT: MEMCHUNK BOOTINFO record too small\n");
+    }
     LTRACEF("MEMCHUNK ptr %p, size %hu\n", ptr, size);
 
-    uint32_t membase = *(uint32_t *)ptr;
-    uint32_t memsize = *(uint32_t *)((uintptr_t)ptr + 4);
+    uint32_t membase = *(const uint32_t *)ptr;
+    uint32_t memsize = *(const uint32_t *)((uintptr_t)ptr + 4);
 
     dprintf(INFO, "VIRT: memory base %#x size %#x\n", membase, memsize);
     novm_add_arena("mem", membase, memsize);
+
+    // TODO: read the rest of the device bootinfo records and dynamically locate devices
 }
 
 void platform_init(void) {

platform/qemu-virt-m68k/rules.mk

@@ -11,6 +11,7 @@ MODULE_DEPS += dev/virtio/block
 MODULE_DEPS += dev/virtio/gpu
 MODULE_DEPS += dev/virtio/net
 
+MODULE_SRCS += $(LOCAL_DIR)/bootinfo.c
 MODULE_SRCS += $(LOCAL_DIR)/goldfish_rtc.c
 MODULE_SRCS += $(LOCAL_DIR)/goldfish_tty.c
 MODULE_SRCS += $(LOCAL_DIR)/pic.c