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.
2026-07-02 16:17:09 +08:00
parent fbc14631e3
commit f1a2a110d7
182 changed files with 16472 additions and 0 deletions
@@ -0,0 +1,56 @@
+#include <utsm/utrw.h>
+#include <utsm/segment.h>
+#include <utsm/pckc.h>
+#include <utsm/crypto.h>
+#include <utsm/config.h>
+
+void *memcpy(void *dst, const void *src, usize len);
+
+int utsm_read(utsm_capability cap, u64 offset, void *dst, u64 len) {
+    if (!dst && len != 0) {
+        return UTSM_ERR_INVALID;
+    }
+    if (len == 0) {
+        return UTSM_OK;
+    }
+
+    utsm_segment_desc *desc = NULL;
+    int status = utsm_cap_validate(cap, UTSM_RIGHT_READ, offset, len, &desc);
+    if (status != UTSM_OK) {
+        return status;
+    }
+
+    utsm_key_material key;
+    status = utsm_pckc_get_or_derive(cap.segment_slot, desc, &key);
+    if (status != UTSM_OK) {
+        return status;
+    }
+
+    u8 line_plain[UTSM_CACHE_LINE_SIZE];
+    u64 seq_before = desc->writer_seq;
+    if (seq_before & 1ULL) {
+        return UTSM_ERR_RETRY;
+    }
+
+    u64 copied = 0;
+    while (copied < len) {
+        u64 absolute = offset + copied;
+        u64 line_start = (absolute / UTSM_CACHE_LINE_SIZE) * UTSM_CACHE_LINE_SIZE;
+        u64 in_line = absolute - line_start;
+        u64 chunk = UTSM_CACHE_LINE_SIZE - in_line;
+        if (chunk > len - copied) {
+            chunk = len - copied;
+        }
+        u64 line_index = line_start / UTSM_CACHE_LINE_SIZE;
+        u64 tweak = utsm_make_tweak(desc->tweak_seed, line_index, desc->key_epoch);
+        utsm_crypt_line(&key, tweak, desc->cipher_base + line_start, line_plain);
+        memcpy((u8 *)dst + copied, line_plain + in_line, chunk);
+        copied += chunk;
+    }
+
+    u64 seq_after = desc->writer_seq;
+    if (seq_before != seq_after) {
+        return UTSM_ERR_RETRY;
+    }
+    return UTSM_OK;
+}