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[boot][kernel] Split programs into sections

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To enable setting sections as NX or read-only, the boot program loader
now loads programs as lists of sections, and the kernel args are updated
accordingly. The kernel's loader now just takes a program pointer to
iterate the sections. Also enable NX in IA32_EFER in the bootloader.
This commit is contained in:
Justin C. Miller
2021-01-20 01:25:47 -08:00
parent 14aad62e02
commit cb612c36ea
13 changed files with 140 additions and 61 deletions
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28
src/boot/hardware.cpp
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@@ -37,8 +37,25 @@ find_acpi_table(uefi::system_table *st)
return reinterpret_cast<void*>(acpi1_table);
}
static uint64_t
rdmsr(uint32_t addr)
{
uint32_t low, high;
__asm__ __volatile__ ("rdmsr" : "=a"(low), "=d"(high) : "c"(addr));
return (static_cast<uint64_t>(high) << 32) | low;
}
static void
wrmsr(uint32_t addr, uint64_t value)
{
uint32_t low = value & 0xffffffff;
uint32_t high = value >> 32;
__asm__ __volatile__ ("wrmsr" :: "c"(addr), "a"(low), "d"(high));
}
void
setup_cr4()
setup_control_regs()
{
uint64_t cr4 = 0;
asm volatile ( "mov %%cr4, %0" : "=r" (cr4) );
@@ -49,6 +66,15 @@ setup_cr4()
0x020000 | // Enable PCIDs
0;
asm volatile ( "mov %0, %%cr4" :: "r" (cr4) );
// Set up IA32_EFER
constexpr uint32_t IA32_EFER = 0xC0000080;
uint64_t efer = rdmsr(IA32_EFER);
efer |=
0x0001 | // Enable SYSCALL
0x0800 | // Enable NX bit
0;
wrmsr(IA32_EFER, efer);
}
} // namespace hw