oops

kernel.ld

+/* Simple linker script for the JOS kernel.
+   See the GNU ld 'info' manual ("info ld") to learn the syntax. */
+
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+ENTRY(_start)
+
+SECTIONS
+{
+	/* Load the kernel at this address: "." means the current address */
+	. = 0xF0100000;
+
+	.text : AT(0x100000) {
+		*(.text .stub .text.* .gnu.linkonce.t.*)
+	}
+
+	PROVIDE(etext = .);	/* Define the 'etext' symbol to this value */
+
+	.rodata : {
+		*(.rodata .rodata.* .gnu.linkonce.r.*)
+	}
+
+	/* Include debugging information in kernel memory */
+	.stab : {
+		PROVIDE(__STAB_BEGIN__ = .);
+		*(.stab);
+		PROVIDE(__STAB_END__ = .);
+		BYTE(0)		/* Force the linker to allocate space
+				   for this section */
+	}
+
+	.stabstr : {
+		PROVIDE(__STABSTR_BEGIN__ = .);
+		*(.stabstr);
+		PROVIDE(__STABSTR_END__ = .);
+		BYTE(0)		/* Force the linker to allocate space
+				   for this section */
+	}
+
+	/* Adjust the address for the data segment to the next page */
+	. = ALIGN(0x1000);
+
+	/* The data segment */
+	.data : {
+		*(.data)
+	}
+
+	PROVIDE(edata = .);
+
+	.bss : {
+		*(.bss)
+	}
+
+	PROVIDE(end = .);
+
+	/DISCARD/ : {
+		*(.eh_frame .note.GNU-stack)
+	}
+}

memlayout.h

+// Memory layout
+
+#define PGSIZE          4096            // bytes mapped by a page
+#define PGSHIFT         12              // log2(PGSIZE)
+
+#define KSTKSIZE        (8*PGSIZE)              // size of a kernel stack
+
+#define IOSPACEB  0x0A0000 // begin IO space
+#define IOSPACEE  0x100000  // end IO space
+#define PHYSTOP   0xE000000 // use phys mem up to here as free pool
+
+// Key addresses for address space layout (see kmap in vm.c for the actual layout)
+#define KERNBASE 0xF0000000  // First kernel virtual address
+#define USERTOP  (KERNBASE-PGSIZE)  // Highest user virtual address
+#define KERNLINK 0xF0100000   // Address where kernel is linked
+
+#ifndef __ASSEMBLER__
+
+static inline uint v2p(void *a) { return (uint) a  - KERNBASE; }
+static inline void *p2v(uint a) { return (void *) a + KERNBASE; }
+
+#endif
+
+#define V2P(a) ((uint) a - KERNBASE)
+#define P2V(a) ((void *) a + KERNBASE)
+