1 files changed, 158 insertions, 0 deletions
diff --git a/roms/ipxe/src/arch/i386/transitions/librm_mgmt.c b/roms/ipxe/src/arch/i386/transitions/librm_mgmt.c
new file mode 100644
index 00000000..cc4765de
--- /dev/null
+++ b/roms/ipxe/src/arch/i386/transitions/librm_mgmt.c
@@ -0,0 +1,158 @@
+/*
+ * librm: a library for interfacing to real-mode code
+ *
+ * Michael Brown <mbrown@fensystems.co.uk>
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/profile.h>
+#include <realmode.h>
+#include <pic8259.h>
+
+/*
+ * This file provides functions for managing librm.
+ *
+ */
+
+/** The interrupt wrapper */
+extern char interrupt_wrapper[];
+
+/** The interrupt vectors */
+static struct interrupt_vector intr_vec[NUM_INT];
+
+/** The interrupt descriptor table */
+struct interrupt_descriptor idt[NUM_INT] __attribute__ (( aligned ( 16 ) ));
+
+/** The interrupt descriptor table register */
+struct idtr idtr = {
+	.limit = ( sizeof ( idt ) - 1 ),
+};
+
+/** Timer interrupt profiler */
+static struct profiler timer_irq_profiler __profiler = { .name = "irq.timer" };
+
+/** Other interrupt profiler */
+static struct profiler other_irq_profiler __profiler = { .name = "irq.other" };
+
+/**
+ * Allocate space on the real-mode stack and copy data there from a
+ * user buffer
+ *
+ * @v data		User buffer
+ * @v size		Size of stack data
+ * @ret sp		New value of real-mode stack pointer
+ */
+uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size ) {
+	userptr_t rm_stack;
+	rm_sp -= size;
+	rm_stack = real_to_user ( rm_ss, rm_sp );
+	memcpy_user ( rm_stack, 0, data, 0, size );
+	return rm_sp;
+};
+
+/**
+ * Deallocate space on the real-mode stack, optionally copying back
+ * data to a user buffer.
+ *
+ * @v data		User buffer
+ * @v size		Size of stack data
+ */
+void remove_user_from_rm_stack ( userptr_t data, size_t size ) {
+	if ( data ) {
+		userptr_t rm_stack = real_to_user ( rm_ss, rm_sp );
+		memcpy_user ( rm_stack, 0, data, 0, size );
+	}
+	rm_sp += size;
+};
+
+/**
+ * Set interrupt vector
+ *
+ * @v intr		Interrupt number
+ * @v vector		Interrupt vector, or NULL to disable
+ */
+void set_interrupt_vector ( unsigned int intr, void *vector ) {
+	struct interrupt_descriptor *idte;
+
+	idte = &idt[intr];
+	idte->segment = VIRTUAL_CS;
+	idte->attr = ( vector ? ( IDTE_PRESENT | IDTE_TYPE_IRQ32 ) : 0 );
+	idte->low = ( ( ( uint32_t ) vector ) & 0xffff );
+	idte->high = ( ( ( uint32_t ) vector ) >> 16 );
+}
+
+/**
+ * Initialise interrupt descriptor table
+ *
+ */
+void init_idt ( void ) {
+	struct interrupt_vector *vec;
+	unsigned int intr;
+
+	/* Initialise the interrupt descriptor table and interrupt vectors */
+	for ( intr = 0 ; intr < NUM_INT ; intr++ ) {
+		vec = &intr_vec[intr];
+		vec->pushal = PUSHAL_INSN;
+		vec->movb = MOVB_INSN;
+		vec->intr = intr;
+		vec->jmp = JMP_INSN;
+		vec->offset = ( ( uint32_t ) interrupt_wrapper -
+				( uint32_t ) vec->next );
+		set_interrupt_vector ( intr, vec );
+	}
+	DBGC ( &intr_vec[0], "INTn vector at %p+%xn (phys %#lx+%xn)\n",
+	       intr_vec, sizeof ( intr_vec[0] ),
+	       virt_to_phys ( intr_vec ), sizeof ( intr_vec[0] ) );
+
+	/* Initialise the interrupt descriptor table register */
+	idtr.base = virt_to_phys ( idt );
+}
+
+/**
+ * Determine interrupt profiler (for debugging)
+ *
+ * @v intr		Interrupt number
+ * @ret profiler	Profiler
+ */
+static struct profiler * interrupt_profiler ( int intr ) {
+
+	switch ( intr ) {
+	case IRQ_INT ( 0 ) :
+		return &timer_irq_profiler;
+	default:
+		return &other_irq_profiler;
+	}
+}
+
+/**
+ * Interrupt handler
+ *
+ * @v intr		Interrupt number
+ */
+void __attribute__ (( cdecl, regparm ( 1 ) )) interrupt ( int intr ) {
+	struct profiler *profiler = interrupt_profiler ( intr );
+	uint32_t discard_eax;
+
+	/* Reissue interrupt in real mode */
+	profile_start ( profiler );
+	__asm__ __volatile__ ( REAL_CODE ( "movb %%al, %%cs:(1f + 1)\n\t"
+					   "\n1:\n\t"
+					   "int $0x00\n\t" )
+			       : "=a" ( discard_eax ) : "0" ( intr ) );
+	profile_stop ( profiler );
+	profile_exclude ( profiler );
+}
+
+PROVIDE_UACCESS_INLINE ( librm, phys_to_user );
+PROVIDE_UACCESS_INLINE ( librm, user_to_phys );
+PROVIDE_UACCESS_INLINE ( librm, virt_to_user );
+PROVIDE_UACCESS_INLINE ( librm, user_to_virt );
+PROVIDE_UACCESS_INLINE ( librm, userptr_add );
+PROVIDE_UACCESS_INLINE ( librm, memcpy_user );
+PROVIDE_UACCESS_INLINE ( librm, memmove_user );
+PROVIDE_UACCESS_INLINE ( librm, memset_user );
+PROVIDE_UACCESS_INLINE ( librm, strlen_user );
+PROVIDE_UACCESS_INLINE ( librm, memchr_user );