Record networking and DMA development progress

Add the current OS source tree, build scripts, system image layout, and development notes covering DMA page allocation, e1000 bring-up, net API dispatch, and DHCP work in progress.

CODE/UTSM/include/utsm/dma.h

@@ -0,0 +1,20 @@
+#ifndef UTSM_DMA_H
+#define UTSM_DMA_H
+
+#include <utsm/types.h>
+
+typedef struct dkm_dma_buffer {
+    void *virt;
+    u64 phys;
+    u64 size;
+} dkm_dma_buffer;
+
+typedef struct dkm_dma_api {
+    int (*alloc_pages)(u64 page_count, u64 alignment, u64 max_phys, dkm_dma_buffer *out);
+} dkm_dma_api;
+
+void dma_init(void);
+int dma_alloc_pages(u64 page_count, u64 alignment, u64 max_phys, dkm_dma_buffer *out);
+const dkm_dma_api *dma_get_api(void);
+
+#endif