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| From: | KONRAD Frederic |
| Subject: | Re: [Qemu-devel] [PATCH V1 1/3] leon3: add a little bootloader |
| Date: | Tue, 23 Apr 2019 16:37:25 +0200 |
| User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 |
Hi Philippe, Le 4/23/19 à 4:20 PM, Philippe Mathieu-Daudé a écrit :
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 <address@hidden> --- 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.
I hesitated but finally I choose to do it like that since all the other OFFSET comes in the second patch.
#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.
No problem. Thanks YOU for the review.
With the comments:
Will add the comments in the V2. Regards, Fred
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>+ 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; } }
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