Commit 93d39210 authored by Cédric Le Goater's avatar Cédric Le Goater Committed by Benjamin Herrenschmidt

powerpc/boot: Define a routine to enter prom

This patch defines a 'prom' routine similar to 'enter_prom' in the
kernel.

The difference is in the MSR which is built before entering prom. Big
endian order is enforced as in the kernel but 32bit mode is not. It
prepares ground for the next patches which will introduce Little endian
order.
Signed-off-by: default avatarCédric Le Goater <clg@fr.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 002c39db
......@@ -126,3 +126,74 @@ RELACOUNT = 0x6ffffff9
/* Call start */
b start
#ifdef __powerpc64__
#define PROM_FRAME_SIZE 512
#define SAVE_GPR(n, base) std n,8*(n)(base)
#define REST_GPR(n, base) ld n,8*(n)(base)
#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base)
#define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
#define SAVE_8GPRS(n, base) SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base)
#define SAVE_10GPRS(n, base) SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base)
#define REST_2GPRS(n, base) REST_GPR(n, base); REST_GPR(n+1, base)
#define REST_4GPRS(n, base) REST_2GPRS(n, base); REST_2GPRS(n+2, base)
#define REST_8GPRS(n, base) REST_4GPRS(n, base); REST_4GPRS(n+4, base)
#define REST_10GPRS(n, base) REST_8GPRS(n, base); REST_2GPRS(n+8, base)
/* prom handles the jump into and return from firmware. The prom args pointer
is loaded in r3. */
.globl prom
prom:
mflr r0
std r0,16(r1)
stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
SAVE_GPR(2, r1)
SAVE_GPR(13, r1)
SAVE_8GPRS(14, r1)
SAVE_10GPRS(22, r1)
mfcr r10
std r10,8*32(r1)
mfmsr r10
std r10,8*33(r1)
/* remove MSR_LE from msr but keep MSR_SF */
mfmsr r10
rldicr r10,r10,0,62
mtsrr1 r10
/* Load FW address, set LR to label 1, and jump to FW */
bl 0f
0: mflr r10
addi r11,r10,(1f-0b)
mtlr r11
ld r10,(p_prom-0b)(r10)
mtsrr0 r10
rfid
1: /* Return from OF */
/* Restore registers and return. */
rldicl r1,r1,0,32
/* Restore the MSR (back to 64 bits) */
ld r10,8*(33)(r1)
mtmsr r10
isync
/* Restore other registers */
REST_GPR(2, r1)
REST_GPR(13, r1)
REST_8GPRS(14, r1)
REST_10GPRS(22, r1)
ld r10,8*32(r1)
mtcr r10
addi r1,r1,PROM_FRAME_SIZE
ld r0,16(r1)
mtlr r0
blr
#endif
......@@ -27,11 +27,17 @@ struct prom_args {
__be32 args[10]; /* Input/output arguments. */
};
#ifdef __powerpc64__
extern int prom(void *);
#else
static int (*prom) (void *);
#endif
void of_init(void *promptr)
{
#ifndef __powerpc64__
prom = (int (*)(void *))promptr;
#endif
}
#define ADDR(x) (u32)(unsigned long)(x)
......
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