Import backup from 2004-07-10

kernel/boot.asm

@@ -1,7 +1,7 @@
 ;boot.asm
 ;Author: Josh Holtrop
 ;Date: 07/08/04
-;Modified: 07/08/04
+;Modified: 07/10/04
 
 
 %define	MULTIBOOT_MAGIC	0x1BADB002

kernel/kernel.c

@@ -3,10 +3,61 @@
 #include "multiboot.h"
 #include "module.h"
 
+mb_info_t mb_info_block;
+mb_mmap_t mb_mmap[MAX_MMAP];
+mb_module_t mb_modules[MAX_MODULES];
+mb_apm_t mb_apm_table;
+char mb_cmdline[256];
 
-
+/* This function runs in segmented memory - 0xC000_0000 is mapped to 0x0 but 0x0
+   itself is an invalid linear address. Therefore, the multiboot information addresses
+   must be manually adjusted by VIRT_OFFSET to become valid linear addresses. */
 int k_mbsave(mb_info_t *mbinfo, unsigned int mb_magic)
 {
+	if (mb_magic != MULTIBOOT_BOOTLOADER_MAGIC)
+	{
+		char *msg = "Bad multiboot magic identifier!";
+		char *dest = (char *) 0xC00B8000;
+		while (*msg)
+		{
+			*dest++ = *msg++;
+			*dest++ = 0x04;		//red error message
+		}
+		for (;;) ;
+	}
+	mb_info_block = *mbinfo;
+	if (mb_info_block.flags & MB_BOOTLOADER_COMMAND_LINE)
+	{
+		mb_info_block.cmdline += VIRT_OFFSET;
+		memcpy(mb_cmdline, mb_info_block.cmdline, 256);
+		mb_cmdline[255] = 0;
+	}
+	if (mb_info_block.flags & MB_BOOTLOADER_MODS)
+	{
+		mb_info_block.mods_addr += VIRT_OFFSET;
+		int i;
+		for (i = 0; i < mb_info_block.mods_count && i < MAX_MODULES; i++)
+		{
+			mb_modules[i] = ((mb_module_t *)mb_info_block.mods_addr)[i];
+		}
+	}
+	if (mb_info_block.flags & MB_BOOTLOADER_MMAP)
+	{
+		mb_info_block.mmap_addr += VIRT_OFFSET - 4;	//-4 to get to size field, not base_addr_low field
+		mb_mmap_t *mmap = (mb_mmap_t *)mb_info_block.mmap_addr;
+		int i, sz = 0;
+		for (i = 0; sz < mb_info_block.mmap_length && i < MAX_MMAP; i++)
+		{
+			sz += mmap->size;
+			mb_mmap[i] = *mmap;
+			mmap = (mb_mmap_t *)(((u32_t) mmap) + mmap->size);
+		}
+	}
+	if (mb_info_block.flags & MB_BOOTLOADER_APM)
+	{
+		mb_info_block.apm_table += VIRT_OFFSET;
+		mb_apm_table = *(mb_apm_t *)mb_info_block.apm_table;
+	}
 	return 0;
 }