1 files changed, 148 insertions, 0 deletions
diff --git a/roms/openbios/arch/sparc64/context.c b/roms/openbios/arch/sparc64/context.c
new file mode 100644
index 000000000..48dae3da5
--- /dev/null
+++ b/roms/openbios/arch/sparc64/context.c
@@ -0,0 +1,148 @@
+/*
+ * context switching
+ * 2003-10 by SONE Takeshi
+ */
+
+#include "config.h"
+#include "kernel/kernel.h"
+#include "context.h"
+#include "libopenbios/bindings.h"
+#include "libopenbios/initprogram.h"
+#include "libopenbios/sys_info.h"
+#include "boot.h"
+#include "openbios.h"
+
+#define MAIN_STACK_SIZE 16384
+#define IMAGE_STACK_SIZE 4096*4
+
+#define debug printk
+
+static void start_main(void); /* forward decl. */
+void __exit_context(void); /* assembly routine */
+
+/*
+ * Main context structure
+ * It is placed at the bottom of our stack, and loaded by assembly routine
+ * to start us up.
+ */
+static struct context main_ctx = {
+    .pc = (uint64_t) start_main,
+    .npc = (uint64_t) start_main + 4,
+    .return_addr = (uint64_t) __exit_context,
+};
+
+/* This is used by assembly routine to load/store the context which
+ * it is to switch/switched.  */
+struct context * volatile __context = &main_ctx;
+
+/* Client program context */
+static struct context *client_ctx;
+
+/* Stack for loaded ELF image */
+static uint8_t image_stack[IMAGE_STACK_SIZE];
+
+/* Pointer to startup context (physical address) */
+unsigned long __boot_ctx;
+
+/* Pointer to Forth context stack */
+void *_fcstack_ptr = &_efcstack;
+
+
+/*
+ * Main starter
+ * This is the C function that runs first.
+ */
+static void start_main(void)
+{
+    /* Save startup context, so we can refer to it later.
+     * We have to keep it in physical address since we will relocate. */
+    __boot_ctx = virt_to_phys(__context);
+
+    /* Set up client context */
+    client_ctx = init_context(image_stack, sizeof image_stack, 1);
+    __context = client_ctx;
+
+    /* Start the real fun */
+    openbios();
+
+    /* Returning from here should jump to __exit_context */
+    __context = boot_ctx;
+}
+
+static uint64_t ALIGN_SIZE(uint64_t x, uint64_t a)
+{
+    return (x + a - 1) & ~(a-1);
+}
+
+#define CTX_OFFSET(n) ALIGN_SIZE(sizeof(struct context) + n * sizeof(uint64_t), sizeof(uint64_t))
+
+/* Setup a new context using the given stack.
+ */
+struct context *
+init_context(uint8_t *stack, uint64_t stack_size, int num_params)
+{
+    struct context *ctx;
+    uint8_t *stack_top = stack + stack_size;
+
+    ctx = (struct context *)(stack_top - CTX_OFFSET(num_params));
+    /* Use valid window state from startup */
+    memcpy(ctx, &main_ctx, sizeof(struct context));
+
+    /* Fill in reasonable default for flat memory model */
+    ctx->return_addr = virt_to_phys(__exit_context);
+
+    return ctx;
+}
+
+/* init-program */
+extern uint64_t sparc64_of_client_interface;
+
+int
+arch_init_program(void)
+{
+    volatile struct context *ctx = __context;
+    ucell entry, param;
+
+    ctx->regs[REG_O0] = 0;
+    ctx->regs[REG_O0+4] = (uint64_t)&sparc64_of_client_interface;
+    ctx->regs[REG_SP] = (uint64_t)malloc(IMAGE_STACK_SIZE) + IMAGE_STACK_SIZE - CTX_OFFSET(0) - STACK_BIAS;
+
+    /* Set param */
+    feval("load-state >ls.param @");
+    param = POP();
+    ctx->param[0] = param;
+
+    /* Set entry point */
+    feval("load-state >ls.entry @");
+    entry = POP();
+    ctx->pc = entry;
+    ctx->npc = entry+4;
+
+    return 0;
+}
+
+/* Switch to another context. */
+struct context *switch_to(struct context *ctx)
+{
+    volatile struct context *save;
+    struct context *ret;
+
+    //debug("switching to new context: entry point %#llx stack 0x%016llx\n", ctx->pc, ctx->regs[REG_SP]);
+    save = __context;
+    __context = ctx;
+    //asm ("pushl %cs; call __switch_context");
+    asm ("call __switch_context; nop");
+    ret = __context;
+    __context = (struct context *)save;
+    return ret;
+}
+
+/* Start ELF Boot image */
+unsigned int start_elf(void)
+{
+    volatile struct context *ctx = __context;
+
+    ctx = switch_to((struct context *)ctx);
+
+    return 0;
+}