leon3: add a little bootloader

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 <chouteau@adacore.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: KONRAD Frederic <frederic.konrad@adacore.com>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
This commit is contained in:
KONRAD Frederic 2019-05-15 14:31:31 +02:00 committed by Mark Cave-Ayland
parent b70447aaea
commit dbed0d2d2a
1 changed files with 71 additions and 8 deletions

View File

@ -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;
}
}