From 2c6b33ce3e2eb287e6a0b25d46b96ba7876fe17a Mon Sep 17 00:00:00 2001 From: Klaus Schnass Date: Mon, 31 Mar 2008 21:02:29 +0000 Subject: Libpayload fixes to prevent triple-faults when running in QEMU. Let the linker figure out the correct address and just CALL the start_main entry point. Signed-off-by: Klaus Schnass Acked-by: Uwe Hermann git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3204 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- payloads/libpayload/i386/head.S | 29 ++++++++++++----------------- payloads/libpayload/i386/main.c | 18 +++++++----------- 2 files changed, 19 insertions(+), 28 deletions(-) (limited to 'payloads') diff --git a/payloads/libpayload/i386/head.S b/payloads/libpayload/i386/head.S index e05cb3ed30..e548329c66 100644 --- a/payloads/libpayload/i386/head.S +++ b/payloads/libpayload/i386/head.S @@ -50,31 +50,26 @@ _init: /* No interrupts, please. */ cli - /* Get the current stack pointer. */ + /* Store current stack pointer. */ movl %esp, %esi + /* Setup new stack. */ movl _istack, %ebx - /* lret needs %cs in the stack, so copy it over. */ - movw %cs, 4(%ebx) + movl (%ebx), %esp - /* - * Exchange the current stack pointer for the one in the initial - * stack (which happens to be the new stack pointer). - */ - xchgl %esi, 16(%ebx) - - /* Set the new stack pointer. */ - movl %esi, %esp - - /* Return into the main entry function and go. */ - lret + /* Save old stack pointer. */ + pushl %esi + /* Let's rock. */ + call start_main + _leave: - movl _istack, %ebx + /* Get old stack pointer. */ + popl %ebx - /* Restore the stack pointer from the storage area. */ - movl 16(%ebx), %esp + /* Restore old stack. */ + movl %esp, %ebx /* Return to the original context. */ lret diff --git a/payloads/libpayload/i386/main.c b/payloads/libpayload/i386/main.c index 066e2a275e..a167218ffc 100644 --- a/payloads/libpayload/i386/main.c +++ b/payloads/libpayload/i386/main.c @@ -36,17 +36,12 @@ * stack we store the original stack pointer from the calling application. */ -static void start_main(void); extern void _leave(void); static struct { - uint32_t eip[2]; - uint32_t raddr[2]; uint32_t esp; -} initial_stack __attribute__ ((section(".istack"))) = { - { (uint32_t) start_main, 0 }, - { (uint32_t) _leave, 0 }, - (uint32_t) & initial_stack, +} initial_stack __attribute__ ((section(".istack"))) = { + (uint32_t) &initial_stack, }; void *_istack = &initial_stack; @@ -55,7 +50,7 @@ void *_istack = &initial_stack; * This is our C entry function - set up the system * and jump into the payload entry point. */ -static void start_main(void) +void start_main(void) { extern int main(void); @@ -70,9 +65,10 @@ static void start_main(void) * user gets control goes here. */ - /* Go to the entry point. */ - - /* In the future we may care about the return value. */ + /* + * Go to the entry point. + * In the future we may care about the return value. + */ (void) main(); /* -- cgit v1.2.3