This adds a little bootloader to the leon3_machine when a ram image is
given through the kernel parameter and no bios are provided:
* The UART transmiter is enabled.
* The TIMER is initialized.
Reviewed-by: Fabien Chouteau <chout...@adacore.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
Signed-off-by: KONRAD Frederic <frederic.kon...@adacore.com>
---
hw/sparc/leon3.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 71 insertions(+), 8 deletions(-)
diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c
index 4f58691..6ba63e6 100644
--- a/hw/sparc/leon3.c
+++ b/hw/sparc/leon3.c
@@ -44,6 +44,8 @@
#define CPU_CLK (40 * 1000 * 1000)
#define LEON3_PROM_FILENAME "u-boot.bin"
+#define LEON3_PROM_OFFSET (0x00000000)
+#define LEON3_RAM_OFFSET (0x40000000)
#define MAX_PILS 16
@@ -62,6 +64,59 @@ typedef struct ResetData {
target_ulong sp; /* initial stack pointer */
} ResetData;
+static uint32_t *gen_store_u32(uint32_t *code, hwaddr addr, uint32_t val)
+{
+ stl_p(code++, 0x82100000); /* mov %g0, %g1 */
+ stl_p(code++, 0x84100000); /* mov %g0, %g2 */
+ stl_p(code++, 0x03000000 +
+ extract32(addr, 10, 22));
+ /* sethi %hi(addr), %g1 */
+ stl_p(code++, 0x82106000 +
+ extract32(addr, 0, 10));
+ /* or %g1, addr, %g1 */
+ stl_p(code++, 0x05000000 +
+ extract32(val, 10, 22));
+ /* sethi %hi(val), %g2 */
+ stl_p(code++, 0x8410a000 +
+ extract32(val, 0, 10));
+ /* or %g2, val, %g2 */
+ stl_p(code++, 0xc4204000); /* st %g2, [ %g1 ] */
+
+ return code;
+}
+
+/*
+ * When loading a kernel in RAM the machine is expected to be in a different
+ * state (eg: initialized by the bootloader). This little code reproduces
+ * this behavior.
+ */
+static void write_bootloader(CPUSPARCState *env, uint8_t *base,
+ hwaddr kernel_addr)
+{
+ uint32_t *p = (uint32_t *) base;
+
+ /* Initialize the UARTs */
+ /* *UART_CONTROL = UART_RECEIVE_ENABLE | UART_TRANSMIT_ENABLE; */
+ p = gen_store_u32(p, 0x80000108, 3);
+
+ /* Initialize the TIMER 0 */
+ /* *GPTIMER_SCALER_RELOAD = 40 - 1; */
+ p = gen_store_u32(p, 0x80000304, 39);
+ /* *GPTIMER0_COUNTER_RELOAD = 0xFFFE; */
+ p = gen_store_u32(p, 0x80000314, 0xFFFFFFFE);
+ /* *GPTIMER0_CONFIG = GPTIMER_ENABLE | GPTIMER_RESTART; */
+ p = gen_store_u32(p, 0x80000318, 3);
+
+ /* JUMP to the entry point */
+ stl_p(p++, 0x82100000); /* mov %g0, %g1 */
+ stl_p(p++, 0x03000000 + extract32(kernel_addr, 10, 22));
+ /* sethi %hi(kernel_addr), %g1 */
+ stl_p(p++, 0x82106000 + extract32(kernel_addr, 0, 10));
+ /* or kernel_addr, %g1 */
+ stl_p(p++, 0x81c04000); /* jmp %g1 */
+ stl_p(p++, 0x01000000); /* nop */
+}
+
static void main_cpu_reset(void *opaque)
{
ResetData *s = (ResetData *)opaque;
@@ -142,7 +197,7 @@ static void leon3_generic_hw_init(MachineState *machine)
/* Reset data */
reset_info = g_malloc0(sizeof(ResetData));
reset_info->cpu = cpu;
- reset_info->sp = 0x40000000 + ram_size;
+ reset_info->sp = LEON3_RAM_OFFSET + ram_size;
qemu_register_reset(main_cpu_reset, reset_info);
/* Allocate IRQ manager */
@@ -164,13 +219,13 @@ static void leon3_generic_hw_init(MachineState *machine)
}
memory_region_allocate_system_memory(ram, NULL, "leon3.ram", ram_size);
- memory_region_add_subregion(address_space_mem, 0x40000000, ram);
+ memory_region_add_subregion(address_space_mem, LEON3_RAM_OFFSET, ram);
/* Allocate BIOS */
prom_size = 8 * MiB;
memory_region_init_ram(prom, NULL, "Leon3.bios", prom_size, &error_fatal);
memory_region_set_readonly(prom, true);
- memory_region_add_subregion(address_space_mem, 0x00000000, prom);
+ memory_region_add_subregion(address_space_mem, LEON3_PROM_OFFSET, prom);
/* Load boot prom */
if (bios_name == NULL) {
@@ -190,7 +245,7 @@ static void leon3_generic_hw_init(MachineState *machine)
}
if (bios_size > 0) {
- ret = load_image_targphys(filename, 0x00000000, bios_size);
+ ret = load_image_targphys(filename, LEON3_PROM_OFFSET, bios_size);
if (ret < 0 || ret > prom_size) {
error_report("could not load prom '%s'", filename);
exit(1);
@@ -220,10 +275,18 @@ static void leon3_generic_hw_init(MachineState *machine)
exit(1);
}
if (bios_size <= 0) {
- /* If there is no bios/monitor, start the application. */
- env->pc = entry;
- env->npc = entry + 4;
- reset_info->entry = entry;
+ /*
+ * If there is no bios/monitor just start the application but put
+ * the machine in an initialized state through a little
+ * bootloader.
+ */
+ uint8_t *bootloader_entry;
+
+ bootloader_entry = memory_region_get_ram_ptr(prom);
+ write_bootloader(env, bootloader_entry, entry);
+ env->pc = LEON3_PROM_OFFSET;
+ env->npc = LEON3_PROM_OFFSET + 4;
+ reset_info->entry = LEON3_PROM_OFFSET;
}
}
--
1.8.3.1
