Hi Frederic,
On 4/19/19 12:18 PM, 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.
>
> Signed-off-by: KONRAD Frederic <frederic.kon...@adacore.com>
> ---
> hw/sparc/leon3.c | 80
> +++++++++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 70 insertions(+), 10 deletions(-)
>
> diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c
> index 774639a..2c6f486 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)
I'd have split this patch in 2, first add/use these definitions, then
the bootloader code, but that's OK.
>
> #define MAX_PILS 16
>
> @@ -53,6 +55,55 @@ typedef struct ResetData {
> target_ulong sp; /* initial stack pointer */
> } ResetData;
>
> +static uint32_t *gen_write_to_addr(uint32_t *code, hwaddr addr, uint32_t val)
Can you rename that gen_store_u32()?
If you prefer gen_write_to_addr() that's fine.
> +{
> + 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 */
> + p = gen_write_to_addr(p, 0x80000108, 3);
Can you add comments?
Here are the notes I took while reviewing, they might be enough:
// *UART_CONTROL = UART_RECEIVE_ENABLE | UART_TRANSMIT_ENABLE;
> +
> + /* Initialize the TIMER 0 */
> + p = gen_write_to_addr(p, 0x80000304, 39);
// *GPTIMER_SCALER_RELOAD = 40 - 1;
> + p = gen_write_to_addr(p, 0x80000314, 0xFFFFFFFE);
// *GPTIMER0_COUNTER_RELOAD = 0xFFFE;
> + p = gen_write_to_addr(p, 0x80000318, 3);
// *GPTIMER0_CONFIG = GPTIMER_ENABLE | GPTIMER_RESTART;
> +
> + /* 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 */
> +}
Thanks for adding write_bootloader(), I really appreciate your effort.
With the comments:
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> +
> static void main_cpu_reset(void *opaque)
> {
> ResetData *s = (ResetData *)opaque;
> @@ -131,11 +182,12 @@ 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 +200,13 @@ 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 +226,7 @@ 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 +250,18 @@ 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;
> }
> }
>
>
