On 03/05/2019 08:53, Mark Cave-Ayland wrote:
> On 25/04/2019 13:18, KONRAD Frederic wrote:
>
>> 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 | 84
>> +++++++++++++++++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 74 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c
>> index 774639a..f25432c 100644
>> --- a/hw/sparc/leon3.c
>> +++ b/hw/sparc/leon3.c
>> @@ -1,7 +1,7 @@
>> /*
>> * QEMU Leon3 System Emulator
>> *
>> - * Copyright (c) 2010-2011 AdaCore
>> + * Copyright (c) 2010-2019 AdaCore
>> *
>> * Permission is hereby granted, free of charge, to any person obtaining a
>> copy
>> * of this software and associated documentation files (the "Software"), to
>> deal
>> @@ -44,6 +44,8 @@
>> #define CPU_CLK (40 * 1000 * 1000)
>>
>> #define PROM_FILENAME "u-boot.bin"
>> +#define LEON3_PROM_OFFSET (0x00000000)
>> +#define LEON3_RAM_OFFSET (0x40000000)
>>
>> #define MAX_PILS 16
>>
>> @@ -53,6 +55,59 @@ 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;
>> @@ -131,11 +186,12 @@ 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 */
>> - grlib_irqmp_create(0x80000200, env, &cpu_irqs, MAX_PILS,
>> &leon3_set_pil_in);
>> + grlib_irqmp_create(0x80000200, env, &cpu_irqs, MAX_PILS,
>> + &leon3_set_pil_in);
>>
>> env->qemu_irq_ack = leon3_irq_manager;
>>
>> @@ -148,13 +204,13 @@ 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) {
>> @@ -174,7 +230,7 @@ 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);
>> @@ -198,10 +254,18 @@ 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;
>> }
>> }
>
> I think this patch is basically okay, however if you don't supply both a
> kernel and
> bios then you get the slightly enigmatic message below:
>
> $ ./qemu-system-sparc -M leon3_generic
> qemu-system-sparc: Can't read bios image (null)
>
> Perhaps add a define for LEON3_BIOS_FILENAME and return that if filename ==
> NULL to
> give a better error message?
Okay I see there is already a PROM_FILENAME that exists and can be used here.
ATB,
Mark.
