1 files changed, 120 insertions, 0 deletions
diff --git a/arch/riscv/kernel/lumeos.lds.S b/arch/riscv/kernel/lumeos.lds.S
new file mode 100644
index 0000000..9bd083b
--- /dev/null
+++ b/arch/riscv/kernel/lumeos.lds.S
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * RISC-V Kernel Linker Script Template
+ *
+ * This is a C-preprocessed linker script (.lds.S). The build system
+ * runs it through CPP to produce the final vmlinux.lds which is
+ * passed to the linker.
+ *
+ * Architecture-specific definitions:
+ *   - OUTPUT_ARCH, ENTRY
+ *   - PAGE_OFFSET, BASE_ADDRESS, PHYS_BASE
+ *   - .head.text placement
+ *   - GP anchor (__global_pointer$ for RISC-V medany)
+ *   - early_pgdir and boot stacks in .bss
+ *
+ * Common section macros come from include/lume/vmlinux.lds.h
+ *
+ * Reference: docs/specs/linker_and_entry.md
+ */
+
+#include <lume/lumeos.lds.h>
+
+/* ===== RISC-V Architecture Constants ===== */
+
+OUTPUT_ARCH(riscv)
+
+PAGE_OFFSET  = 0xFFFFFFC000000000;
+BASE_ADDRESS = 0xFFFFFFC080200000;
+PHYS_BASE    = 0x80200000;
+
+ENTRY(_start)
+
+/* ===== RISC-V: GP anchor in .data (medany model) ===== */
+#define ARCH_DATA_EXTRA                         \
+    . = ALIGN(16);                              \
+    PROVIDE(__global_pointer$ = . + 0x800);     \
+    *(.sdata .sdata.*)
+
+/* ===== RISC-V: page-table storage + per-CPU boot stacks in .bss =====
+ *
+ * Linux RISC-V layout (arch/riscv/kernel/vmlinux.lds.S):
+ *   early_pg_dir       — first early page table built by setup_vm,
+ *                        used for the rest of boot after MMU enable
+ *   trampoline_pg_dir  — single-page table used only during the SATP
+ *                        switch from physical to higher-half VA; its
+ *                        identity + virt mappings of _start must both
+ *                        be valid in the same instruction window
+ *   fixmap_pg_dir      — covers the FIXADDR_START range used by the
+ *                        early console (UART MMIO before kernel page
+ *                        table proper is built)
+ *
+ * All three are allocated here so head.S can take their addresses without
+ * a C definition; their PA == VA mapping covers them during setup_vm.
+ */
+#define ARCH_BSS_EXTRA                          \
+    . = ALIGN(4096);                            \
+    early_pg_dir = .;                           \
+    . += 4096;                                  \
+    trampoline_pg_dir = .;                      \
+    . += 4096;                                  \
+    fixmap_pg_dir = .;                          \
+    . += 4096;                                  \
+    /* Legacy name retained for any caller still referencing it; */ \
+    /* points at the same first 4 KiB as early_pg_dir. */            \
+    early_pgdir = early_pg_dir;                 \
+    /* Per-CPU boot stacks: 8KB per CPU, max 8 CPUs */              \
+    . = ALIGN(4096);                            \
+    boot_stack = .;                             \
+    . += 8192 * 8;                              \
+    boot_stack_top = .;
+
+/* ===== Layout ===== */
+
+SECTIONS {
+    . = BASE_ADDRESS;
+
+    /* .head.text: Image Header (must be at byte 0 of the kernel image) */
+    .head.text : AT(PHYS_BASE) {
+        _start = .;
+        KEEP(*(.head.text))
+    }
+
+    TEXT_SECTION
+
+    . = ALIGN(4096);
+
+    /* .rela.dyn lives between .text and .rodata so it ends up in the
+     * read-only PT_LOAD segment.  Mirrors Linux vmlinux.lds.S where
+     * .rela.dyn sits at the tail of init data, just before RO_DATA. */
+    RELA_DYN_SECTION
+
+    . = ALIGN(4096);
+
+    RODATA_SECTION
+
+    . = ALIGN(4096);
+
+    DATA_SECTION
+
+    . = ALIGN(8);
+
+    /* .got lives right after .data in the RW PT_LOAD.  All other
+     * dynamic-linker artefacts (.plt, .dynamic, .dynsym, .dynstr,
+     * .hash, .gnu.hash, .interp, .dynbss) are discarded by the
+     * DISCARDS macro — mirrors Linux arch/riscv/kernel/vmlinux.lds.S. */
+    GOT_SECTION
+
+    . = ALIGN(4096);
+
+    /* End of file-backed image (BSS follows as NOBITS) */
+    __lume_image_end = .;
+
+    BSS_SECTION
+
+    KERNEL_END
+
+    DISCARDS
+}