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-rw-r--r--arch/riscv64/config.h53
-rw-r--r--arch/riscv64/gen/asm-offsets.c26
-rw-r--r--arch/riscv64/include/tcb.h8
-rw-r--r--arch/riscv64/init/init.c29
-rw-r--r--arch/riscv64/init/start.S1
-rw-r--r--arch/riscv64/kernel/irq.c12
6 files changed, 104 insertions, 25 deletions
diff --git a/arch/riscv64/config.h b/arch/riscv64/config.h
index 33c84a0..bdf31ae 100644
--- a/arch/riscv64/config.h
+++ b/arch/riscv64/config.h
@@ -7,44 +7,74 @@
* and immutable parameters. Included on the command line by
* -include.
*
+ * Assume Sv39, probably wouldn't be too difficult to use runtime parameters
+ * instead. First 4K is reserved for NULL, but I suppose it could be mapped
+ * later if *absolutely* necessary.
+ *
* @todo Consider separating user-specified and immutable parameters.
+ * @todo Write more thorough documentation, maybe a separate .md file?
*/
#include <apos/sizes.h>
/* --- START ARCH USER CONFIG VALUES --- */
-/* physical address to which the kernel will be loaded */
+/** Physical address to where the OS image will be loaded. */
#define RAM_BASE 0x80000000
+/* --- END ARCH USER CONFIG VALUES --- */
+
+/* don't touch >:( */
+
+/** Physical address to where the kernel proper will be relocated. */
#define PM_KERN_BASE (RAM_BASE + SZ_512K)
+
+/** Maximum size of the kernel proper. Largely arbitrary. */
#define PM_KERN_SIZE (SZ_256K)
+
+/** Highest allowed physical address where kernel stuff may lie. */
#define PM_KERN_TOP (PM_KERN_BASE + PM_KERN_SIZE)
-/* --- END ARCH USER CONFIG VALUES --- */
-/* don't touch >:( */
+/** Physical memory stack base. In this case, right after the kernel. */
+#define PM_STACK_BASE (PM_KERN_BASE + PM_KERN_SIZE)
-#define PM_STACK_BASE (PM_KERN_BASE + SZ_256K)
+/** Size of physical memory stack. */
#define PM_STACK_SIZE (SZ_256K)
+
+/** Top of physical memory stack. */
#define PM_STACK_TOP (PM_STACK_BASE + PM_STACK_SIZE)
-#if __riscv_xlen == 64
+#if defined(riscv64)
/* 64bit */
+
+/** Direct map offset. */
#define VM_DMAP (0xffffffc000000000) /* testing for now */
+
+/** Virtual address of kernel proper inside direct mapping. */
#define VM_KERN (VM_DMAP + SZ_256K)
+/** Page reserved for kernel I/O. */
#define IO_PAGE 511UL
+
+/** Direct mapping starts from this page. */
#define KSTART_PAGE 256UL
+
+/** The RPC stack page. */
#define CSTACK_PAGE 255UL
-/* assume Sv39, probably wouldn't be too difficult to use runtime parameters
- * instead. First 4K is reserved for NULL, but I suppose it could be mapped
- * later if *absolutely* necessary. */
+/** User virtual memory space start. */
#define UVMEM_START (SZ_4K)
+
+/** User virtual memory space end. */
#define UVMEM_END (SZ_256G - SZ_1G)
-#define PROC_STACK_TOP (SZ_256G)
-#define PROC_STACK_BASE (SZ_256G - SZ_1G)
+/** RPC stack top. */
+#define RPC_STACK_TOP (SZ_256G)
+
+/** RPC stack base. */
+#define RPC_STACK_BASE (SZ_256G - SZ_1G)
+
#else
/* 32bit */
+
/* TODO: figure this stuff out */
#define VM_DMAP (0x000000000)
#define VM_KERN (VM_DMAP + SZ_256K)
@@ -55,9 +85,6 @@
#define KSTART_PAGE 512UL
#define CSTACK_PAGE 511UL
-/* assume Sv39, probably wouldn't be too difficult to use runtime parameters
- * instead. First 4K is reserved for NULL, but I suppose it could be mapped
- * later if *absolutely* necessary. */
#define UVMEM_START (SZ_4K)
#define UVMEM_END (SZ_4G - SZ_8M)
diff --git a/arch/riscv64/gen/asm-offsets.c b/arch/riscv64/gen/asm-offsets.c
index fbe2726..71a1c9a 100644
--- a/arch/riscv64/gen/asm-offsets.c
+++ b/arch/riscv64/gen/asm-offsets.c
@@ -7,12 +7,36 @@
#include <apos/utils.h>
#include "../kernel/regs.h"
-/* largely based on linux */
+/**
+ * Insert assembly comment with calculated value.
+ * Largely based on linux
+ *
+ * @param sym Name of symbol.
+ * @param val Value of symbol.
+ */
#define DEFINE(sym, val) \
__asm__ volatile ("\n#-> " #sym " %0 " #val "\n" : : "i" (val))
+
+/**
+ * Insert offset of member in structure.
+ *
+ * @param m Member.
+ * @param s Structure.
+ */
#define OFFSETOF(m, s) DEFINE(offsetof_##m, offsetof(s, m))
+
+/**
+ * Insert size of structure.
+ *
+ * @param n Name of structure.
+ * @param s Structure.
+ */
#define SIZEOF(n, s) DEFINE(sizeof_##n, sizeof(s))
+/**
+ * Generate assembly with calculated offsets and sizes.
+ * See arch/riscv64/gen/source.mk for how the assembly is used.
+ */
void asm_offsets()
{
OFFSETOF(ra, struct riscv_regs);
diff --git a/arch/riscv64/include/tcb.h b/arch/riscv64/include/tcb.h
index be6d58a..8cd32ed 100644
--- a/arch/riscv64/include/tcb.h
+++ b/arch/riscv64/include/tcb.h
@@ -6,9 +6,13 @@
* riscv64 definitions of arch-specific tcb data.
*/
+/**
+ * riscv-specific thread handling stuff.
+ *
+ * Empty for now, but should probably be filled with stuff like register
+ * saving of something
+ */
struct arch_tcbd {
- /* empty for now, but should probably be filled with stuff like register
- * saving of something */
};
#endif /* ARCH_RISCV_TCB_H */
diff --git a/arch/riscv64/init/init.c b/arch/riscv64/init/init.c
index 5fe463a..db428dd 100644
--- a/arch/riscv64/init/init.c
+++ b/arch/riscv64/init/init.c
@@ -11,13 +11,22 @@
#include <arch/vmem.h>
#include "../kernel/csr.h"
-/* assume 64 bit for now */
+/** Temporary virtual memory space.
+ * Assume 64bit riscv for now.
+ */
struct vmem *root_branch;
+/**
+ * Create page table entry.
+ * Copy from \ref arch/riscv64/kernel/vmem.c.
+ *
+ * @param a Virtual address.
+ * @param f PTE flags.
+ */
#define to_pte(a, f) (((a) >> 12) << 10 | (f))
-/* assume Sv39 for now */
-void init_bootmem()
+/** Jump into virtual memory. */
+static void init_bootmem()
{
size_t flags = VM_V | VM_X | VM_R | VM_W;
@@ -41,7 +50,8 @@ void init_bootmem()
csr_write(CSR_SATP, SATP_MODE_Sv39 | ((uintptr_t)root_branch >> 12));
}
-void move_kernel()
+/** Relocate kernel proper. */
+static void move_kernel()
{
extern char *__init_end;
extern char *__kernel_size;
@@ -53,6 +63,12 @@ void move_kernel()
dst[i] = src[i];
}
+/**
+ * Convert an existing physical address in a register to a virtual address.
+ * There is probably an easier way to do this, but this seems to work alright.
+ *
+ * @param reg Register to modify.
+ */
#define __va_reg(reg) \
{ \
vm_t reg = 0; \
@@ -61,6 +77,11 @@ void move_kernel()
__asm__ ("mv " QUOTE(reg) ", %0" ::"rK" (reg) :); \
}
+/**
+ * Main driver for the init loader.
+ *
+ * @param fdt Global FDT pointer, provided by bootloader.
+ */
void init(void *fdt)
{
extern char *__init_end;
diff --git a/arch/riscv64/init/start.S b/arch/riscv64/init/start.S
index 7842946..f5ed2fe 100644
--- a/arch/riscv64/init/start.S
+++ b/arch/riscv64/init/start.S
@@ -1,5 +1,6 @@
.section .init.start
.global _start
+/* Entry point to the kernel loader. */
_start:
li sp, PM_STACK_TOP
call init
diff --git a/arch/riscv64/kernel/irq.c b/arch/riscv64/kernel/irq.c
index 15fa750..6fdfe85 100644
--- a/arch/riscv64/kernel/irq.c
+++ b/arch/riscv64/kernel/irq.c
@@ -8,7 +8,13 @@
#include <arch/irq.h>
#include "csr.h"
-extern void handle_irq(void);
+/** Defined in arch/riscv64/kernel/entry.S. */
+extern void handle_irq();
+
+/** Called from arch/riscv64/kernel/entry.S. */
+void handle_sys_irq()
+{
+}
void init_irq(void *fdt)
{
@@ -20,10 +26,6 @@ void init_irq(void *fdt)
info("CSR_SIE: %lx\n", s);
}
-void handle_sys_irq()
-{
-}
-
/* very simple for now */
void enable_irq()
{
generated by cgit v1.3 (git 2.53.0) at 2026-08-27 03:49:11 +0000